ECS and Wheel Aligment_KMC

8/18/2019 ECS and Wheel Aligment_KMC

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WHEEL ALIGNMENT & ECS

WHEEL ALIGNMENTWHEEL ALIGNMENT

& ECS& ECS

Chonan Technical Service Training Center 1




CONTENTS

WHEEL ALIGNMENT

NECESSITY OF WHEEL ALIGNMENT ---------------------------------------------------------

WHAT HAPPENS DURING AN ALIGNMENT -------------------------------------------------

EQUIPMENT REQUIREMENTS ------------------------------------------------------------------

HEIGHT MUST BE RIGHT -------------------------------------------------------------------------

DIAGNOSIS PROCEDURE FOR ALIGNMENT ----------------------------------------------

CAMBER ------------------------------------------------------------------------------------------------

CASTER -------------------------------------------------------------------------------------------------

TOE -------------------------------------------------------------------------------------------------------

STEERING AXIS INCLINATION (SAI) ----------------------------------------------------------

INCLUDED ANGLE ----------------------------------------------------------------------------------

STEERING OFFSET ---------------------------------------------------------------------------------

SET BACK ----------------------------------------------------------------------------------------------

THRUST ANGLE --------------------------------------------------------------------------------------

STEERING CENTER ---------------------------------------------------------------------------------

TOE OUT ON TURNS --------------------------------------------------------------------------------

DIAGNOSIS BY VEHICLE SYMPTOM ----------------------------------------------------------

INTEGRATED FRAME AND BODY (MONOCOQUE) ---------------------------------------

SUSPENSION SYSTEMS ---------------------------------------------------------------------------

FRONT SUSPENSION -------------------------------------------------------------------------------

REAR SUSPENSION ---------------------------------------------------------------------------------

SPRUNG WEIGHT AND UNSPRUNG WEIGHT ----------------------------------------------

SIMPLIFIED SUSPENSION MODEL -------------------------------------------------------------

OSCILLATION OF SPRUNG WEIGHT -----------------------------------------------------------





SEMI-ACTIVE ECS

SEMI-ACTIVE ECS (Ele!"#$% C#$!"#lle S'e$%#$) ----------------------------------

SKY HOOK SYSTEM ----------------------------------------------------------------------------------

SKY HOOK DAMPER - ADVANTAGE OF REVERSE TYPE DAMPER -----------------

SYSTEM PERFORMANCE --------------------------------------------------------------------------

CONSTRUCTION AND OPERATION OF SHOCK ABSORBER --------------------------

ECS SHOCK ABSORBER ---------------------------------------------------------------------------

DAMPING FORCE CHARACTERISTICS --------------------------------------------------------

SEMI-ACTIVE CONTROL ----------------------------------------------------------------------------

CONSTRUCTION OF SEMI-ACTIVE ECS ------------------------------------------------------

INPUTS & OUTPUTS ----------------------------------------------------------------------------------

INPUTS

*) ECS CONTROL MODULE POWER SUPPLY ---------------------------------------------

+) ALTERNATOR ,L, TERMINAL ----------------------------------------------------------------

) BRAKE SWITCH ---------------------------------------------------------------------------------

.) ECS MODE SWITCH (SPORT/NORMAL SWITCH) ------------------------------------

0) VEHICLE SPEED SENSOR -------------------------------------------------------------------

1) STEERING SENSOR ----------------------------------------------------------------------------

2) THROTTLE POSITION SENSOR ------------------------------------------------------------

3) ACCELERATION SENSOR (G-SENSOR) ---------------------------------------------------

OUTPUTS

*) ACTUATOR RELAY -----------------------------------------------------------------------------

+) ECS LAMP -----------------------------------------------------------------------------------------

) SOLENOID VALVE (PROPORTIONAL TYPE) --------------------------------------------

DTC LIST ------------------------------------------------------------------------------------------------

DIAGNOSTIC TROUBLE CODE ------------------------------------------------------------------

WIRING DIAGRAM -----------------------------------------------------------------------------------





WHEEL ALIGNMENT

NECESSITY OF WHEEL ALIGNMENT

Wheel alignment is just adjusting the relationshi !et"een the susension and steering





comonents# the "heels# and the $rame o$ the vehicle% ehicle manu$acturers determine "hich

angles are adjusta!le $rom the $actor' !ased on need and $easi!ilit'% arious adjustment

mechanisms such as shims# cams# threaded rods and slotted $rames usuall' rovide enough

adjustment# roviding height is correct# to !ring the vehicle into seci$ication% When the angles are

all as seci$ied# the car or truc( is roerl' aligned# and the !est ossi!le comromise has !een

achieved among minimum rolling $riction# ma)imum tire mileage# sta!ilit' o$ the car on the road#

and steering control $or the driver% ehicle accident# road shoc( and general "ear and tear can

ma(e some o$ these angles out o$ sec% When that haens# control o$ the vehicle ma' !e

threatened# and the tires ma' !egin to "ear unevenl' and raidl'% The car needs to !e realigned to

have all the roer angles restored%

The "arning signs suggesting the need $or alignment are*

-Irregular "ear on tires% Loo( closel' at all $our o$ 'our tires% I$ one or more o$ them

demonstrate e)cessive "ear on one side# or "ear in a cued# scalloed or diagonal strie

attern at edges or across the tread# or uneven "ear !ut "ith +$eathered+ edges on the

treads# an alignment could !e needed%

- ,nusual steering $eeling% I$ the steering $eels sti$$er than it used to# or i$ the "heel does not

return to the center osition "hen released# or i$ the car $eels s(ittish the "heels ma' !e out

o$ alignment%

- I$ the steering "heel ulls to one side "hen the $ront "heels are ointing straight ahead# an

alignment is almost certainl' needed%

-While driving# i$ the car "ants to ull to one side# tends to "ander or "eave# or is su!ject to

$ront end +shimm'+# 'ou should have the alignment chec(ed immediatel'%

- There are three !asic "heel angles such as Cam!er# Caster and Toe "hich determine

"hether a vehicle is roerl' aligned and goes "here it is ointed% These three angles must

!e set roerl' $or the alignment to !e correct%

- -our."heel alignment is essential on vehicles "ith $ront "heel drive /-W01 and

indeendent rear susension% The rear "heels should $ollo" the $ronts in a arallel ath% I$

the rear "heels are ointed in a slightl' di$$erent direction# the' a$$ect tire "ear and the

vehicle2s sta!ilit'%

Common alignment errors to avoid are*

- -ailing to er$orm an accurate vehicle insection# including height measurement# to

assure a 3ualit' alignment%

- -ailing to ull the rear turn.late ins during a thrust alignment%

- 4vertor3uing rear hu! attachment !olts# causing ossi!le $ull or artial contact shim

de$ormation%





- 5emem!ering to insect the vehicle $or the resence o$ a rear shim rior to cutting a ne"

one%

4ther $acts should !e (no"n a!out "heel alignments*

- A "heel alignment should al"a's start and end "ith a test drive%

- The $ront end and steering lin(age should !e chec(ed $or "ear !e$ore er$orming an

alignment%

- The tires should all !e in good shae "ith even "ear atterns%

- 6ulling ro!lems are not al"a's related to "heel alignment# ro!lems "ith tires# !ra(es

and o"er steering can also !e resonsi!le% It is u to a good "heel alignment technician to

determine the cause%

WHAT HAPPENS DURING AN ALIGNMENT

7e$ore a "heel alignment# a thorough insection o$ the entire undercar# including susension arts#

!ushings# steering lin(age# !all joints and "heel !earings# "heels and tires as "ell as the vehicle2s

$rame and ride height% Loosened or !ent arts need to !e chec(ed% 4nce this insection is

comlete# the car "ill !e chec(ed and adjusted on the alignment machine in order# cam!er# caster

and toe# !eginning "ith the rear "heels%

Items to !e chec(ed !e$ore the measurement o$ "heel alignment are *

- Tire in$lation ressure /under standard condition1

- ,neven "ear o$ tires or di$$erence in tire si8es

- 7all joint la' due to "ear

- Tie rod end la' due to "ear

- -ront "heel !earing la' due to "ear

- Lengths o$ le$t and right strut !ars

- 0e$ormation or "ear o$ steering lin(age arts

- 0e$ormation or "ear o$ arts related to $ront susension

- Chassis.to.ground clearance

Alignment chec(s are recommended "henever steering# susension arts# or some $ront."heel

drive /-W01 driveline comonents are relaced# or "hen ne" tires are installed# or "hen

customers comlain o$ vehicle ulling or a!normal tire "ear such as scu$$ing# cuing or more

accelerated "ear on one side o$ the tire%





The t'e o$ alignment er$ormed usuall' is conditional uon the amount o$ adjustment that2s

$easi!le on a articular vehicle# as "ell as the sho2s e3uiment caa!ilit'% 4n solid.a)le# rear.

"heel.drive /5W01 vehicles# $or e)amle# a thrust alignment is usuall' er$ormed so the $ront

"heels are aligned to the rear a)le% The drive direction o$ the rear a)le is re$erred to as the thrust

line# "hich should in theor' !e the same as the geometric center o$ the vehicle%

A $our."heel alignment involves adjusting the rear "heels to achieve roer cam!er and toe and a

thrust angle as close to 8ero as ossi!le# then adjusting the $ront "heels to the same vehicle

centerline% -our."heel alignments are recommended $or most -W0 cars# M6/Multi 6urose

ehicles1# some S,/Sort ,tilit' ehicles1 and 5W0 vehicles "ith indeendent susension%

EQUIPMENT REQUIREMENTS

To er$orm a $our."heel alignment# a $our.sensor machine is re3uired% Turnlates or rear sli

lates at all $our corners are needed during !oth $our."heel and thrust alignments% The rear

"heels must !e allo"ed to rela) to their normal osition to achieve roer readings "hether the'

are to !e adjusted or not%

In addition to roviding caster# cam!er and toe readings# alignment machines can !e used as a

diagnostic tool% 0iagnostic angles such as Steering A)is Inclination /SAI1# Included Angle /IA1#

Set!ac( and Turning 5adius can hel the technician to identi$' ro!lems that other"ise might !e

overloo(ed% When the SAI reading is com!ined "ith the cam!er reading# the sum o$ the t"o

angles e3uals the IA% ,sing SAI9IA and cam!er "ill hel identi$' a !ent or shi$ted comonent% The

otimum setting on all vehicles $or Set!ac( is 8ero# so either a ositive or negative Set!ac(

reading indicates cradle shi$ting or some other comonent has moved%

Turning 5adius# also re$erred to as toe.out on turns# is determined !' the steering arms relative to

the lo"er steering ivot% When the vehicle is steered into a turn# the steering arms cause the

"heels to turn at di$$erent angles# creating a toe.out condition% I$ the turning radius is incorrect#


T4"'! l%$e

Ge#5e!"%e$!e" l%$e




insect the steering arm and lo"er steering ivot comonents $or damage% ,sing the turnlates on

alignment e3uiment# a technician can chec( $or a !ent steering arm !' measuring the amount o$

toe.out on turns $or each "heel and comare them%

HEIGHT MUST BE RIGHT

Some o$ toda'2s alignment e3uiment also can diagnose ride height# "hich is critical to roer

alignment and susension geometr'% 5ide height is the angle that all "heel alignment angles are

!uilt around and should !e (et "ithin manu$acturer seci$ications $or otimum er$ormance o$ the

entire steering# susension and driveline s'stem%

When vehicles have !een modi$ied $rom the manu$acturer2s original design# $actor' alignmentsettings ma' no longer al'% Altering tire si8es ma' uset the sindle2s distance $rom the ground#

"hich can have an e$$ect on scru! radius% 5aising or lo"ering vehicle height ma' alter the

susension and steering s'stems2 geometr' during de$lection and cause e)cessive toe change or

stress some arts !e'ond their limits%

Wea(# sagging srings can $orce the entire steering and

susension s'stem to go out o$ roer alignment# "hich sells

ro!lems $or an' vehicle% A correct alignment "ith a sagged

susension can still roduce tire "ear and handling ro!lems

during d'namic oeration% The !est "a' to $i) the ride height is

to relace the srings /Note* srings should onl' !e relaced

in matched airs1% Changes in riding height "ill a$$ect cam!er

and toe so i$ srings are relaced or torsion !ars are adjusted#

then the "heel alignment must !e chec(ed to avoid the

ossi!ilit' o$ tire "ear% It is imortant to note that the onl'

s'mtom o$ "ea( coil srings is a sag in the riding height% I$

the riding height is good# then the srings are good%

Air susended vehicles ma' have a seci$ied rocedure that is necessar' to achieve the correctalignment height rior to adjustment% 4n some air susension s'stems# it is $irst necessar' to

allo" the air in the air sring to reach sho temerature rior to alignment%

-ailure to detect incorrect chassis height can o$ten lead a technician to a "rong diagnosis# such

as attri!uting the lac( o$ adjustment range to a !ent $rame%

DIAGNOSIS PROCEDURE FOR ALIGNMENT


:Cam!er change !'a sagging sring;




Tire# !ra(e and driveline ro!lems are o$ten mista(en $or an alignment ro!lem !' the vehicle

o"ner# so the customer should !e consulted as to "hat made them thin( the vehicle needs

aligning% 7egin !' as(ing the customer a $e" simle 3uestions# such as* What is 'our vehicle

doing to ma(e 'ou thin( 'ou need an alignment< 0oes it ull< When does it ull< Is the steering

"heel straight< Are the tires "orn unevenl'<

Ne)t# veri$' the ro!lem "ith a test drive and a comlete insection o$ the tires and the "ear

atterns the' disla' that indicate a steering or susension ro!lem% I$ the customer is getting ne"

tires# e)amine the old ones $or unusual "ear !e$ore the' come o$$ the vehicle% E)lain to the

customer ho" ne" tires "ill e)erience the same "ear as the old ones unless the underl'ing

cause o$ the ro!lem is corrected%

I$ a loose steering or susension art is discovered# sho" the customer the actual ro!lem% I$

ossi!le# demonstrate a roerl' $unctioning art on a similar vehicle in the sho $or comarison%0ue to the hectic schedule in most shos# this ste is sometimes overloo(ed even though eole

learn !est $rom hands.on e)erience%

It2s essential to al"a's !e recise "hen discussing $actor' seci$ications $or steering and

susension comonents% Some chassis arts must e)ceed a listed tolerance $or looseness to

actuall' re3uire relacement% In man' cases# the art can !e "ithin its tolerance range !ut still

contri!ute to tire "ear# alignment and handling ro!lems% Some amount o$ looseness "ithin this

sec could create ro!lems $or the driver o$ the vehicle# !ut the relacement is not re3uired until

the tolerance is reached% When ma(ing a service suggestion to the customer# e)lain that

although the !all joint ma' !e "ithin its listed tolerance# the looseness could allo" "heel

movement and create alignment angle changes% A art that is loose# !ut still "ithin its listed

tolerance# should never !e descri!ed as !ad%

Some steering comonents such as tie rod ends ma' not have a listed tolerance% Insection o$

these comonents ma' rel' entirel' on the technician2s judgment# using hand ressure or some

other aroved method as a measure o$ e)cessive looseness%

CAMBER

Cam!er is the angle o$ the "heel# measured in degrees# "hen

vie"ed $rom the $ront o$ the vehicle% The $ront "heels o$ the

car are installed "ith their tos tilted out"ard or in"ard% This is

called cam!er and is measured in degrees o$ tilt $rom the

vertical% When the to o$ a "heel is tilted out"ard# it is called

ositive cam!er% Conversel'# in"ard inclination is called

negative cam!er%

Chonan Technical Service Training Center 9:Cam!er;




4n man' vehicles# cam!er changes "ith di$$erent road

seeds% This is !ecause aerod'namic $orces cause a change

in riding height $rom the height o$ a vehicle at rest% 7ecause o$

this# riding height should !e chec(ed and ro!lems corrected

!e$ore setting cam!er% -or man' 'ears the trend has !een to

set the cam!er $rom 8ero to slightl' ositive to o$$set vehicle

loading# ho"ever the current trend is to slightl' negative

settings to increase vehicle sta!ilit' and imrove handling%

I$ the cam!er is out o$ adjustment# it "ill cause tire "ear on

one side o$ the tire2s tread% I$ the cam!er is too $ar negative# $or

instance# then the tire "ill "ear on the inside o$ the tread% 4n

man' $ront."heel.drive vehicles# cam!er is not adjusta!le% I$

the cam!er is out on these cars# it indicates that something is

"orn or !ent# ossi!l' $rom an accident and must !e reaired

or relaced%

P#%!%6e C758e"

Slight ositive cam!er results in a d'namic loading that allo"s

the tire to run relativel' $lat against the road sur$ace% 6ositive

cam!er also directs the "eight and shoc( load o$ the vehicle

on the larger inner "heel !earing and in!oard ortion o$ the

sindle rather than the out!oard !earing% 6ositive cam!er in

moderation results in longer !earing li$e# less li(el' sudden

load $ailure# and as a side !ene$it# easier steering% E)cessive

ositive cam!er "ears the outside o$ the tire and can cause

"ear to susension arts such as "heel !earings and

sindles%

Giving the "heel ositive cam!er causes the load to !e

alied to the inner side o$ the sindle# reducing the $orce

acting on the sindle and the steering (nuc(le%

The reactive $orce# "hich is e3ual in si8e to the vehicle load# is

alied to the "heel erendicularl' to the road% this is divided

into erendicular $orce to the a)is o$ the sindle and arallel

$orce to the a)is o$ the sindle "hich $orces the "heel in"ard#

heling to revent the "heel $rom sliing o$$ the sindle% The

inner "heel !earing is made larger than the outer one in order

to !ear this load%


:Cam!er "ear attern;

:ehicle load & Wheel !earing;

Ve4%le l#7

I$$e"94eel

8e7"%$:

:ehicle load & Wheel !earing;

Ve4%le l#7

O'!e"94eel

8e7"%$:




Ne:7!%6e C758e"

ariations in negative cam!er can !e used to imrove the

handling o$ a vehicle; A setting o$ =9>? negative on !oth sides

"ill imrove cornering "ithout a$$ecting tire li$e greatl'% This

negative setting comensates $or the slight ositive cam!er

change o$ the outside tire due to vehicle roll# there!' allo"ing a

$latter tire contact atch during cornering% E)cessive negative

cam!er "ears the inside o$ the tire and similar to ositive

cam!er# it can cause "ear and stress on susension arts%

Re7" C758e"

5ear cam!er is not adjusta!le on most rear "heel drive vehicles% These vehicles are !uilt "ith 8ero

cam!er setting and are strong enough not to $le) or !end under normal load% Most $ront "heel drive

vehicles have a manu$acturers seci$ication calling $or a slight amount o$ rear cam!er# usuall' a

small amount o$ negative cam!er $or cornering sta!ilit'% I$ the manu$acturers seci$ication allo"s# a

setting o$ @? to .@%?/B@1 is re$erred $or tire "ear and ride sta!ilit'% I$ rear cam!er settings change#

de$ected rear susension arts are necessaril' relaced% Ho"ever# most vehicles can !e adjusted

!' using an a$termar(et t'e o$ adjustment# such as shims# cam !olts or !ushings%

R#7 C"#9$ 7$ C758e"

A cro"ned road means that the outside9right hand side o$ the lane is lo"er than the le$t side o$ the

lane% This imroves the drainage o$ the road !ut adversel' a$$ects vehicle handling% 5oad cro"n

must !e comensated $or in alignment settings !ecause a vehicle driving on a cro"ned road leans

to the right# causing some "eight trans$er to the right# and the cam!er changes slightl' more

ositive% This com!ination creates a ull or dri$t to the right% Most alignment technicians adjust the

vehicle "ith a slightl' more ositive cam!er# usuall' =9D?/=1# on the le$t to comensate $or the

road cro"n% This slightl' more ositive cam!er "ill not cause a noticea!le ull "hen driving on a

$lat road% Ho"ever# i$ cam!er is une3ual $rom side to side "ith a di$$erence greater than =9>?/B@1#

the vehicle "ill ull to the side "ith the most ositive cam!er% I$ the seci$ications allo"# @? to

@%?/B@1 is usuall' !est $or tire li$e and vehicle handling%

C7'e #< C758e" C47$:e

- 5ide height

Al"a's chec( a ride height seci$ication rior to

!eginning alignment% Changes in ride height $rom

seci$ications a$$ect cam!er%


:Misaligned Cam!er;

P'll%$: !#!4e "%:4!




- Sagging o$ sring

As a vehicle ages# the susension has a tendenc'

to sag% E)cessive vehicle "eight or a!use can

cause srings to "ea(en%

- Sagging o$ cross.mem!er or su!.$rame

Another $actor to consider is sagging o$ cross.

mem!er or su!.$rame% Modi$ications to the vehicle

such as raising or lo"ering the susension or

changing the total "eight o$ the vehicle can also

a$$ect cam!er%

P"#8le5 C7'e 8= I$#""e! C758e"

- ehicle ulls to one side

- 5aid "ear on inside or outside o$ tire tread

- Increased "ear on the "heel !earings%

- Increased "ear on !all joints /incorrect cam!er creates

increased leverage on sindle and sindle suort

resulting in increased loads on !all joints1%

CASTER

Caster can !e de$ined as the $or"ard or rear"ard tilt o$ the steering (nuc(le ivot oints# is also

called the steering a)is% Caster is measured in degrees# $rom the steering a)is to true vertical# as

vie"ed $rom the side% 4n strut e3uied vehicles# the line e)tends through the lo"er !all joint to the

center o$ the uer strut mount%

The caster angle is $ormed !' the steering a)is and a true vertical line assing through the sindle%

The urose o$ caster angle is to rovide directional control sta!ilit' $or the $ront "heels to travel a

straight course "ith minimal e$$ort% 6roer caster angle also hels to return the $ront "heels to a

straight ahead osition a$ter a turn% Caster has little a$$ect on tire "ear%

6urose o$ Caster are *





- To aid in the directional control o$ the vehicle !' heling the $ront "heels maintain a

straight ahead osition

- To hel return the $ront "heels to straight ahead osition a$ter a turn%

-To o$$set the e$$ects o$ road cro"n on vehicle direction%

- To oerate in concert "ith the vehicle susension design# cam!er angle and steering a)is

inclination angle to rovide the desired cam!er change during vehicle turns%

Man' $ront."heel.drive vehicles# caster is not adjusta!le% I$ the caster is out sec# it indicates that

something is "orn or !ent# ossi!l' $rom an accident# and must !e reaired or relaced%

P#%!%6e 7!e"

6ositive caster is "hen the to o$ the steering a)is it tilted

rear"ard% The caster line intersects the ground ahead o$ the

contact atch o$ the tire# "hich rovides good directional control%

Ho"ever# e)cessive ositive caster can cause t"o ro!lems%

The $irst is that e)cessive caster "ill cause a high level o$ road

shoc( to !e transmitted to the driver "hen the vehicle hits a

!um and it causes hard steering%

The second ro!lem is that a tire "ith ositive caster has a

tendenc' to toe in"ard "hen the vehicle is !eing driven% I$ one

side has more ositive caster than the other# this causes it totoe in"ard "ith more $orce than the other side% This "ill cause

a lead or ull to the side "ith least amount o$ ositive caster%

Ne:7!%6e 7!e"

Negative caster is "hen the to o$ the steering a)is

is tilted $or"ard% This laces the oint contact ahead o$

the oint o$ load# "hich rovides easier steering at

slo"er seeds%

Ho"ever# it can cause di$$icult' in returning out o$ a

turn and "andering & "eaving at high seeds and

is a$$ected !' an' road sur$ace variation such as

small road irregularities or !ums% I$ the caster is

too negative# the steering "ill !e light and the

vehicle "ill "ander and !e di$$icult to (ee in a

straight line%


F#"97"

:6ositive Caster;

F#"97"

:Negative Caster;




>e"# 7!e"

Fero caster is "hen the to o$ the steering a)is is

e)actl' vertical% I$ the vehicle has une3ual caster#

the vehicle ulls to the side "ith the least ositive caster%

A ma)imum side to side variation o$ @%?/B@1 is

recommended on most vehicles%

M#6e5e$! #< %$le 94%le !'"$%$:

With ositive caster# the sindle o$ inner "heel

moves do"n and the sindle o$ outer "heel moves

u "hile turning%

Ho"ever# it causes the sindle to rise and $all as

the "heels are turned in one direction or the other%

7ecause the tire cannot !e $orced into the ground

as the sindle travels in an arc# the tire9"heel

assem!l' raises the susension%

That is "h' steering e$$ort increases "hen theositive caster goes u%

TOE

The toe measurement is the di$$erence in the distance !et"een the $ront o$ the tires and the !ac( o$

the tires% Toe.in# or ositive toe# is de$ined as the $ront o$ the tires !eing closer together than the

rear o$ the tires% Toe.out# or negative toe# is "hen the rear o$ the tires are closer together than the

$ront o$ the tires% Fero toe is "hen the tires are arallel to each other%

Since most alignment seci$ications sho" toe as

total toe o$ !oth "heels# it is imortant to

understand that =9> o$ the total toe should !e

alied to each $ront "heel% A minus /.1 indicates a

toe.out and toe.in is sho"n as a ositive /1%

T#e-%$ ? B @ A T#e-#'! ? B A

It is imortant to note that although toe has

historicall' !een measured as a distance in


F#"97"

:6ositive Caster;

:Sindle movement "hile turning;

:Toe & Toe angle;




milliliters or decimal inches /7.A1# it is !ecoming

more common to e)ress toe in degrees /α#β1% The

idea is that the angle# rather than an ar!itrar'

distance# determines the side sli o$ the tire% Thisshould not !e a$$ected !' the tire si8e# !ut rather

should !e constant $or a given measurement%

E)1 Toe.in /7.A1 mm/in%1 * @>mm /@@%@ in%1 or @%@° ± @%@° /each o$ α#β1

R#le #< T#e 7$:le

The main $unction o$ toe angle is to cancel out the cam!er thrust generated "hen cam!er is

alied% When the $ront "heels are given ositive cam!er# the' tilt out"ard at the to% This causes

them to attemt to roll out"ard as the car moves $or"ard# and there$ore to side.sli% This su!jectsthe tires to "ear% There$ore# toe.in is rovided $or the $ront "heels to revent this !' canceling

out"ard rolling due to cam!er% Since cam!er aroaches 8ero in most recent vehicles# the toe

angle value is also !ecoming smaller%

S'e$%#$ "%:%%!= 7$ T#e 7$:le

0uring driving# $orces $rom various direction are !rought to !ear on the susension# "ith the result

that the "heels tend to toe out% In order to revent this# some vehicles are given a slight toe.in even

"hen the cam!er is 8ero%

E<<e! #< T#e

E)cessive toe increases tire scu$$ing and results in tire "ear and drag on the vehicle% E)cessive

toe.in# or ositive toe# increases scu$$ing on the outside o$ the tire% E)cessive toe.out# or negative

toe# increases scu$$ing on the inside o$ the tire# and in some cases can cause a darting or

"andering ro!lem%

Earl' indication o$ toe tire "ear can aear as a $eather edge

or scu$$ on the edge o$ the tire tread sur$ace% Toe tire "ear can

also !e $ound on rear tires as a cuing# $eather edge or smooth edge on the tire tread sur$ace% Too much toe in "ill

cause the $eather edge to oint in "hile toe out "ill cause the

$eather edge to oint out% Toe is adjusted !' turning the tie rod

turn!uc(les%

ariation $rom $actor' secs is usuall' caused !' "orn or !ent susension arts or changes in

caster# cam!er settings% Toe angle can also !e a$$ected !' !od' structure or $rame damage%


:Toe "ear attern;




T#e 7'!5e$!

a% -ront Toe adjustment

To adjust $ront toe.in# change the lengths o$ the tie rod connecting the steering (nuc(le%

- Increasing the tie rod length * increases toe.in%

- Increasing

the tie rod length

* increases

toe. out%

!% 5ear Toe adjustment5ear "heel alignment o$ an indeendent rear

susension is accomlished !' adjusting the cam!er

and toe angle% The method o$ adjusting the cam!er

and toe angle di$$ers deending on the t'e o$

susension% Some models have no mechanism $or

adjusting the cam!er%

7' turning the eccentric cam# the arm can !e moved to

the le$t or right to change the direction o$ the "heel#

thus adjusting the toe.in%

As "ith $ront toe.in# i$ the length o$ the rear arms are

not made the same in order to adjust the toe.in o$ the

rear "heels searatel'# the angles o$ the le$t and right

"heels "ill di$$er no matter ho" correct the toe.in is%

-or this reason# $irst o$ all# correct the angles o$ the le$t

and right "heels# then adjust the toe.in%


:Increase o$ Toe.in; :0ecrease o$ Toe.in;

:Correct adjustment;




STEERING AXIS INCLINATION (SAI)

The a)is around "hich the "heel rotates as it turns to the right

or le$t# is called the steering a)is% Steering A)is is an imaginar'

line through the uer and lo"er !all joints /ivot joints1 on

short & long arm susensions /e)% 0ou!le Wish!one t'e

susension1% This a)is is $ound !' dra"ing an imaginar' line

!et"een the to o$ the shoc( a!sor!ers uer suort

!earing and the lo"er susension arm !all joint /in the case o$

strut t'e susensions1%

Steering A)is Inclination /SAI1 is the angle !et"een the

centerline o$ the steering a)is and vertical line $rom center

contact area o$ the tire /as vie"ed $rom the $ront1% SAI is also

re$erred to as J6I /Jing 6in Inclination1 on truc(s and old cars

"ith (ing ins instead o$ !all joints%

Steering o$$set# or Jingin o$$set is the distance !et"een the

"heel center and the oint at "hich the steering a)is intersects

the road sur$ace% It is negative "hen the oint o$ intersection is

!et"een the center and the outside o$ the "heel%

SAI rovides good driving and handling characteristics through

directional sta!ilit' and "eight rojection% 0irectional Sta!ilit'

is the tendenc' o$ a "heel to straighten $rom a turned osition

and remain straight%


Steering o$$set

SAI

:SAI o$ Mac6herson Strutt'e susension;

:SAI o$ 0ou!le Wish!onet'e susension;




Since the "heel turns to the right and le$t "ith the steering a)is

as its center and the o$$set as the radius# a large o$$set "ill

generate a great moment around the steering a)is due to the

rolling resistance o$ the tire# thus increasing steering e$$ort%

I$ the o$$set is too large# the reactive $orces acting on the

"heels during driving o$ !ra(ing# "ill generate a moment

around the relevant steering a)is# causing the "heel to ull to

the side ull eseciall' at ver' slo" seeds% This moment is

roortional to the si8e o$ the o$$set% As the o$$set aroaches

8ero# less moment is generated around the steering a)is "hen

a $orce is alied to the "heel# and the steering is less

in$luenced !' !ra(ing or road shoc(

Thus# since it has a tendenc' to maintain or see( a straight ahead osition# less ositive caster isneeded to maintain directional sta!ilit'% A vehicle rovides sta!le handling "ithout an' de$ects o$

high ositive caster !ecause o$ SAI%

SAI/C758e"/IA T"#'8le4##!%$: C47"! (M7P4e"#$ S!"'! !=e 'e$%#$)

SAI Cam!er Included Angle 6ro!lem Area

E3ual to Secs More than Secs More than Secs 7ent Sindle and9or Strut 7od'

More than Secs More than Secs More than SecsStrut To"er IN at To and Sindle or

Strut 7ent

Less than Secs More than Secs E3ual to Secs7ent Control Arm or Strut 4,T at To

and 7ent Sindle or 7ent Strut 7od'

Less than Secs More than Secs Less than Secs7ent Control Arm or Strut 4,T at To

and 7ent Sindle or Strut 7od'

Less than Secs More than Secs More than Secs7ent Control Arm or Strut 4,T at To

and 7ent Sindle or Strut 7od'

E3ual to Secs Less than Secs Less than Secs 7ent Sindle and9or 7ent Strut 7od'

Less than Secs Less than Secs Less than SecsStrut To or 7ent Control Arm and

7ent Sindle or Strut 7od'

More than Secs Less than Secs E3ual to Secs Strut To"er IN at To

SAI/C758e"/IA T"#'8le4##!%$: C47"! (D#'8le W%48#$e !=e 'e$%#$)





SAI Cam!er Included Angle 6ro!lem Area

More than Secs E3ual to Secs Less than SecsSindle9Jnuc(le or ,er Control

Arm and9or Control Arm Mount

Less than Secs E3ual to Secs More than Secs7ent Lo"er Control Arm and9or

Lo"er Control Arm Mount

E3ual to Secs More than Secs More than Secs Sindle9Jnuc(le Assem!l'

Less than Secs More than Secs E3ual to Secs 7ent Lo"er Control Arm

Less than Secs More than Secs More than SecsSindle9Jnuc(le Assem!l'

7ent Lo"er Control Arm

E3ual to Secs Less than Secs Less than Secs Sindle9Jnuc(le Assem!l'

More than Secs Less than Secs E3ual to Secs 7ent ,er Control Arm

Me7'"%$: P"#e'"e

SAI should al"a's !e measured a$ter 'ou have adjusted the cam!er and caster to the roer

seci$ications or as close to the seci$ications as ossi!le% Chec( $or "orn susension arts% SAI is

!est measured "ith the $ront "heels o$$ the ground# !ra(es alied and alignment e3uiment

leveled and loc(ed% 5aise the vehicle underneath the lo"er control arms !ut do not rela) thesusension% Not raising the vehicle $rom the turnta!les can cause the control arm !ushings to

move "hen "heels are turned# resulting in an inaccurate reading%

Ho"ever SAI is t'icall' not adjusta!le% The most li(el' cause $or SAI !eing out is !ent arts "hich

must !e relaced to correct the condition% A ma)imum variation side.to.side o$ =%@? ma' also

indicate vehicle damage%

INCLUDED ANGLEIncluded angle is not directl' measura!le% It is the com!ination o$

SAI and cam!er% ie"ed $rom the $ront# the included angle is SAI

lus cam!er i$ the cam!er is ositive /Included angle "ill !e

greater than the SAI1% I$ the cam!er is negative the included angle

is SAI minus cam!er /Included angle "ill !e less than the SAI1%

The included angle must !e the same $rom side to side even i$ the

cam!er is di$$erent% I$ a side.to.side variation greater than =%?

e)ists# then something is !ent# most li(el' the steering (nuc(le%

SAI Cam!er K Included Angle /I9A1

Chonan Technical Service Training Center 19 :Included Angle;

SAI Cam!er




STEERING OFFSET

Steering o$$set# or Jingin o$$set is the distance at the road

sur$ace !et"een the tire line and the SAI line e)tended do"n"ard

through the steering a)is% The line through the steering a)is

creates a ivot oint around "hich the tire turns% There$ore this

distance must !e e)actl' the same $rom side to side other"ise the

vehicle "ill ull strongl' at all seeds%

6ositive steering o$$set is "hen the tire contact atch is outside o$

the SAI ivot# "hile negative steering o$$set is "hen the contact

atch is in!oard o$ the SAI ivot /$ront "heel drive vehicles usuall'have negative steering o$$set1%

The greater the steering o$$set /ositive or negative1# the greater the steering e$$ort and the more

road shoc( and ivot !inding that ta(es lace% When the vehicle has !een modi$ied "ith o$$set

"heels# larger tires# de$lated tires# height adjustments and side to side cam!er di$$erences# the

steering o$$set "ill !e changed and the handling and sta!ilit' o$ the vehicle "ill !e a$$ected%

Steering o$$set is designed at the $actor' and is not adjusta!le% I$ 'ou have a vehicle that is ulling

even though the alignment is correct# loo( $or something that "ill a$$ect steering o$$set%

SET BACK

-ront set !ac( is "hen one $ront "heel is set $urther !ac(

than the other "heel% And rear set !ac( is "hen one rear

"heel is set $urther !ac( than the other "heel% E)cessive

set.!ac( is normall' created !' $rame or chassis errors%

These errors are !rought a!out in most cases !' $ront

end collision and in some cases !' a manu$acturing

tolerance error% I$ the $rame is adjusted incorrectl'# or

damage is resent# it is not unusual to also see a

reduced ositive caster reading on the side "ith the

set!ac( condition%

5ear set!ac( ma' !e caused $rom $rame# chassis# and rear chassis mis.alignment due to collision%

I$ the vehicle has a set!ac( condition# the vehicle ma' ull to the oosite side o$ the set!ac(%

E)cessive set!ac( can cause an alignment ull to the side "ith the set!ac(% I$ the rear a)le is

ositioned correctl' and all other arts and s'stems o$ the vehicle are in good "or(ing order# a

set!ac( condition "ill also create di$$erent "heel!ase measurement side to side%


Steering o$$set /1

Set 7ac(




THRUST ANGLE

Thrust angle is the angle $ormed !' the thrust line and the geometric centerline% The geometric

centerline is a line dra"n !et"een the mid.oint o$ the $ront a)le and the mid.oint o$ the rear a)le%

I$ the thrust angle is not 8ero# then the vehicle "ill +dog trac(+ and the steering "heel "ill not !e

centered% When toe is di$$erent on either o$ the rear "heels# it creates a thrust angle that causes

rear a)le steer% The thrust line dictates the osition o$ the $ront "heels "hen driving straight ahead%

It is there$ore the most accurate re$erence "hen measuring or adjusting the $ront "heels%

Insection o$ the tires can hel in diagnosing some "heel alignment $ailures% The tire "ear atterns

associated "ith imroer alignment include single shoulder "ear# cuing and $eather edging%

STEERING CENTER

Steering center is siml' the $act that the steering "heel is

centered "hen the vehicle is traveling do"n a straight and

level road% When setting steering center# the rear toe

should !e set $irst !ringing the thrust angle as close to the

vehicle centerline as ossi!le% Then the steering "heel is

loc(ed in a straight ahead osition "hile the $ront toe is

set% 7e$ore loc(ing the steering "heel# the engine should

!e started and the "heel should !e turned right and le$t a

coule o$ times to ta(e an' stress o$$ the o"er steering

valve% 4$ course# 'ou should al"a's road test the vehicle

a$ter ever' alignment as a 3ualit' control chec(%


Centerline

Thrust lineThrust Angle

: 6ositive Thrust Angle;

: Steering center;




TOE OUT ON TURNS

I$ the right and le$t steering angles

"ere the same# the' "ould have the

same turning radius /r = K r >1# !ut

each "heel "ould turn around a

di$$erent center# /4= and 4>1%

Smooth turning "ould there$ore !e

imossi!le due to side.sliing o$

the tires% The result is that# eventhough the air ressure in each o$

the tires might !e e3ual# and even

though the other "heel alignment

$actors might !e correct# the tires

"ould undergo unusual "ear%

-or this reason# the inside $ront

"heel must steer at a sharer angle

than the outside "heel% This is also

(no"n as the Ac(erman e$$ect% In anactual vehicle# Toe 4ut 4n Turns is

accomlished !' the steering

lin(age is modi$ied in such a "a'

that the roer steering angles o$ the

le$t and right $ront "heels are

attained# to achieve the desired

turning radii% The steering arm is

either art o$ the steering (nuc(le or


:At same turning radius /K1;

:At di$$erent turning radius /1;




art o$ the !all joint and is not

adjusta!le%

To chec( toe out on turns# ma(e sure that the readings are at 8ero on each side "hen the "heels

are straight ahead and then steer the "heels to the le$t so that the inner "heel is at >@?# the out"heel should !e less than >@?# otimal reading is =?% 5eeat the test in the other direction# I$ there

is a ro!lem "ith the toe.out# it is due to a !ent steering arm that must !e relaced%





DIAGNOSIS BY VEHICLE SYMPTOM

Ve4%le

S=5!#5P#%8le C7'e

Ve4%le

S=5!#5P#%8le C7'e

E)cessive "heel9rim runout% Worn or de$ective shoc(s9struts%

6o"er steering reaction !rac(et loose% Tires out o$ !alance%

Steering gear !o) /rac(1 mount loose% Incorrect "heel alignment%

Steering gear adjustment loose% Incorrect tire in$lation%

Tires out o$ !alance% 7ra(es dragging%

Tires out o$ round% Mismatched tires or 5adial 6ull%

Wheel !earings "orn or loose% -rame !ent%

Worn steering9susension comonents% Control arm !ushing "orn%

7all joint tight or sei8ed% 6o"er steering valve not centered%

7ent steering (nuc(le or suorts% 7ro(en or sagging srings%

0amaged susension comonents% ,neven s"a' !ar lin(s%

-ront tire ressure lo"% Incorrect "heel alignment%

Idler arm !ushing too tight% Incorrect tire in$lation%

6o"er steering $luid lo" or !elt loose% Wrong tires $or vehicle%

6o"er steering um de$ective% Worn shoc(9strut%

Steering gear out o$ adjustment% Imroer vehicle height%

Incorrect "heel alignment%5ac( & 6inion or steering not ositioned

correctl'%

Incorrect tire in$lation% Sta!ili8er !ar missing or de$ective%

Susension9steering s'stem "orn% Worn steering comonents%

,neven or sagging srings% Worn strut rod or control arm !ushings%

Imroer torsion !ar adjustment% Worn susension comonents%

6remature

Tire Wear

6remature

Tire Wear

6ulls To4ne Side

ehicle

Wandering

-ront End

Shimm'

Hard

Steering





INTEGRATED FRAME AND BODY (MONOCOQUE)

The integrated $rame and !od' t'e o$ construction also re$erred to as uniti8ed construction#

com!ines the $rame and !od' into a single# one.iece structure% This is done !' "elding the

comonents together# !' $orming or casting the entire structure as one iece# or !' a com!ination

o$ these techni3ues% Siml' !' "elding a !od' to a conventional $rame# ho"ever# does not

constitute an integral $rame and !od' construction% In a trul' integrated structure# the entire $rame.

!od' unit is treated as a load.carr'ing mem!er that reacts to all loads e)erienced !' the vehicle.

road loads as "ell as cargo loads%

:Integrated $rame and !od';

Integrated.t'e !odies $or "heeled vehicles are $a!ricated !' "elding re$ormed metal anels

together% The anels are re$ormed in various load.!earing shaes that are located and oriented so

as to result in a uni$orml' stressed structure% Some ortions o$ the integrated structure resem!le

$rame.li(e comonents# "hile other resem!les !od'.li(e anels% This is not surrising# !ecause thestructure must er$orm the $unctions o$ !oth o$ these elements%

An integrated $rame and !od' t'e construction allo"s an increase in the amount o$ noise

transmitted into the assenger comartment o$ the vehicle% Ho"ever# this disadvantage is negated

!' the $ollo"ing advantages*

- Su!stantial "eight reduction# "hich is ossi!le "hen using a "ell.designed uniti8ed !od'

- Lo"er cargo $loor and vehicle height

- 6rotection $rom mud and "ater re3uired $or drive line comonents on amhi!ious vehicles

- 5eduction in the amount o$ vi!ration resent in the vehicle structure


K




SUSPENSION SYSTEMS

I$ a car is running on er$ectl' smooth# level road# it "ill receive hardl' an' shoc( $rom the sur$aceo$ the road% Ho"ever# since there are generall' man' holes and !ums in most roads# the car is

continuall' su!jected to road shoc(% I$ there "ere no rearations made to reduce this shoc( to a

tolera!le level# several ro!lems "ould arise% The assengers "ould e)erience uncom$orta!le

vi!ration# oscillation# and jolting% The vehicle "ould !e di$$icult to handle and severe shoc( could

damage the vehicle or the assengers as "ell as the !aggage !eing carried% In order to imrove

!oth riding com$ort and driving sta!ilit'# an arrangement o$ srings and rods is there$ore rovided

!et"een the "heels and the vehicle !od' to reduce the amount o$ shoc( and oscillation that is

transmitted directl' to the !od'%

The susension s'stem "or(s "ith the tires# $rame or uniti8ed !od'# "heels# "heel !earings# !ra(e

s'stem and steering s'stem% All o$ the comonents o$ these s'stems "or( together to rovide a

sa$e and com$orta!le means o$ transortation% The susension s'stem $unctions are as $ollo"s*

- 6rovide a smooth# com$orta!le ride !' allo"ing the "heels and tires to move u and do"n

"ith minimum movement o$ the vehicle%

- Wor( "ith the steering s'stem to hel (ee the "heels in correct alignment%

- Jee the tires in $irm contact "ith the road# even a$ter stri(ing !ums or holes in the road%

- Allo" raid cornering "ithout e)treme !od' roll /vehicle leans to one side1%

- Allo" the $ront "heels to turn $rom side to side $or steering%

- 6revent e)cessive !od' s3uat /!od' tilts do"n in rear1 "hen accelerating or "ith heav'

loads%

- 6revent e)cessive !od' dive /!od' tilts do"n in the $ront1 "hen !ra(ing%

NONINDEPENDENT SUSPENSION (S#l% Ale)

The non.indeendent susension has

!oth le$t and right "heels attached to the

same solid a)le% When one tire hits a

!um in the road# its u"ard movement

causes a slight tilt in the other "heel%


:Non.indeendent susension;




INDEPENDENT SUSPENSION

The indeendent susension allo"s one "heel to

move u and do"n "ith a minimum e$$ect on the

other "heels% Since each "heel is attached to its

o"n susension# movement o$ one "heel does

not cause direct movement o$ the "heel on the

oosite side o$ the vehicle% With the indeendent$ront susension the use o$ !all joints rovides

ivot oints $or each "heel% In oeration# the

s"iveling action o$ the !all joints allo"s the "heel

and sindle assem!lies to !e turned le$t and right

and to move u and do"n "ith changes in road

sur$aces% This t'e o$ susension is most "idel'

used on modern vehicles%

FRONT SUSPENSION

A !ig di$$erence !et"een the $ront and rear susensions is that the $ront "heels have to !e steered%

When a car corners or goes over !ums# it is su!jected# via the "heels# to a variet' o$ $orces% The

susension must !e a!le to revent these $orces $rom de$lecting the car $rom the course selected

!' the driver% Also# it must not allo" the "heels to "o!!le# move $or"ard# !ac("ard and side"a's#

or alter their angle o$ tilt to an' serious degree# as this "ould inter$ere "ith the handling o$ the car%

a% Mac6herson strut t'e

The strut t'e susension is comosed o$ the lo"er arms#

strut !ars# sta!ili8er !ar and strut assem!lies% The coil

srings are mounted on the strut assem!l'# and the shoc(

a!sor!er is !uilt into the strut assem!l'% 4ne end o$ the

lo"er arm is attached to the $ront side mem!er via a ru!!er

!ushing# and can move $reel' u and do"n% The other end o$

mounted on the steering (nuc(le arm !' means o$ a !all

joint%

Since the shoc( a!sor!er acts as a art o$ the susension

lin(age# !esides !eing a!le to stand u to and a!sor! road


:Indeendent susension.D lin( s'stem;

:Mac6herson strut t'e;




shoc( and oscillation# it must also !e strong enough to !ear

the vertical load that is laced on it% Its to end is mounted

on the $ender aron via the uer suort# "hich is

comosed o$ a ru!!er cushion and a !earing% It can turn

$reel' a!out its a)is% The !ottom end o$ the strut assem!l' is

$astened to the steering (nuc(le arm "ith !olts%

The strut !ars "ithstand the $orce !eing e)erted $rom the "heels in the longitudinal direction% 4ne

end is $astened to the lo"er arm and the other end is mounted via a ru!!er cushion to a strut !ar

!rac(et "elded to the $ront cross mem!er%

!% 0ou!le "ish!one t'e

This t'e is called !ecause the lo"er and uer arms are the shae o$ "ish!ones% The sindle is a

highl' comle) construction in this s'stem# as are the "ish!ones themselves% This raidl'

!ecoming one o$ the most $avored susension t'es $or ne" cars as it gives e)cellent road.holding

caa!ilities "hile ta(ing u ver' little room under the car%

4n the "ish!one t'e# "hen the vehicle !od' is rolling# the "heels tilt in the same direction as the

!od' does% There$ore# the "heels tr' to go in a direction oosite to the direction the vehicle is

!eing turned in% As a result# i$ the "ish!one t'e susension is used $or the $ront susension# the

vehicle has a tendenc' to understeer# !ut i$ it is used $or the rear susension# oversteering tends to

occur%

REAR SUSPENSION

In most vehicle# the rear susension must carr' most o$ the e)tra "eight o$ the assengers and

luggage% This leads to a di$$icult ro!lem% I$ the susension srings are made hard or sti$$ to handle

this e)tra load# the' "ill !e too hard $or the driver "ho drives alone% on the other hand# i$ so$t# the'

"ill !e too so$t "hen the car is $ull' loaded% The same also alies to the shoc( a!sor!ers% This

ro!lem can !e solved !' using coil srings or other t'es o$ lea$ srings having a varia!le sring

constantO oil.$illed shoc( a!sor!ersO di$$erent t'es o$ indeendent susension%





SPRUNG WEIGHT AND UNSPRUNG WEIGHT

All o$ the "eight o$ the !od' "hich is suorted !' vehicle srings is called srung "eight% This

includes the !od'# $rame# engine# transmission and etc% 4n the other hand# unsrung "eight is the

"eight o$ arts "hich is not suorted !' srings% This includes tires# "heels# a)les and etc%

The greater srung "eight o$ the vehicle is o!tained# the !etter riding com$ort !ecomes% 7ecause

the tendenc' to !e a$$ected !' the shoc( or oscillation delivered $rom the road sur$ace through the

sring decreases as the srung "eight !ecomes larger%

SIMPLIFIED SUSPENSION MODEL

-ollo"ing icture is a simli$ied model o$ vehicle susension% This model is enough to e)lain the

$unction o$ susension s'stem%

Chonan Technical Service Training Center 29:-igure =% Simli$ied

susension model; :-igure >% i!ration o$ Srung "eight9,nsrung "eight;




m1 = Srung "eight # m2 = ,nsrung "eight# k 1 = Susension sring rate#

k 2 = Tire sring rate# c 1 = 0amer daming rate# c 2 = Tire daming rate

When an amlitude Pa is alied to the simli$ied susension model /-igure=1# -igure > sho"s the

variation o$ amlitude o$ m= and m> at each $re3uenc' !and%

According to the -igure ># m= and m> has resonance a$$ecting the amlitude o$ each other% C= and

C> have an e$$ect on amlitude at resonance# ho"ever the' do not a$$ect the resonance $re3uenc'%

The resonance $re3uenc' o$ srung "eight or unsrung "eight# that is# natural $re3uenc' is#

Natural $re3uenc' /srung "eight1# $ n= K @%Q /√(=9m=1 ............. /=1

Natural $re3uenc' /unsrung "eight1 $ n> K @%Q /√/(=(>19m>1 ............. />1

-or the ride $eeling it is !etter to reduce the susension sring rate (= and increase the srung

"eight m=% Ho"ever "hen the natural $re3uenc' o$ srung "eight $ n= is getting reduced#

seasic(ness is more $re3uentl' e)erienced% The $ n= range o$ vehicle is usuall' at =%= R =%DH8%

Natural $re3uenc' o$ the unsrung "eight $ n> is usuall' little !it higher than $n=% When the $ n> is

increasing# ride $eeling is oor !ecause oscillation acceleration o$ the srung "eight increases due

to resonance o$ the unsrung "eight%

Ho"ever# "hen the $ n> is lo"# road holding !' tires is oor% There$ore the natural $re3uenc' o$ the

unsrung "eight need to !e adjusted not high and not lo" t o revent this% Normal range o$ $ n> is

=BR=%

OSCILLATION OF SPRUNG WEIGHT





a% 6itching

6itching is the u.and.do"n oscillation o$ the

$ront and rear o$ the vehicle% This haens

eseciall' "hen the car goes over large ruts

o$ !ums in the road or "hen going over an

unaved road "hich is rough and $ull o$

otholes Also# itching occurs more easil' in

vehicles "ith so$ter srings than in those

"ith harder srings%

!% 5olling

While turning or running on a !um' road#

the srings on one side o$ the vehicle

e)and# "hile those on the other side

contract% This causes the vehicle !od' rolling

in the side.to.side direction%

The $ollo"ings are to reduce 5ollingO

=1 Lo" vehicle center height>1 Large Tread

B1 Higher susension sring rate

D1 Higher tire rigidit'

c% 7ouncing

7ouncing is the u.and.do"n movement o$

the "hole vehicle !od'% When a car is

running on an undulated sur$ace "ith a high

seed# !ouncing is li(el' to occur% Also# it

occurs easil' "hen the srings are so$t%

d% a"ing

a"ing is a turning motion around the

vertical a)is o$ the vehicle% At high seed

"hen a vehicle is steered a"ing occurs and

then 5olling $ollo"s% a"ing and 5olling is

ver' related% a"ing haens right a$ter





steering# ho"ever# 5olling occurs little !it

later%

SEMI-ACTIVE ECS

VEHICLE? OPIRUS





SEMI-ACTIVE ECS (Ele!"#$% C#$!"#lle S'e$%#$)

Semi.active susension s'stem is !ased on the S('.Hoo( theor'% This Continuous aria!le Semi.

Active susension s'stem "ith a roortional actuator# !ased on the reverse daming $orce t'e

damer to achieve smoother ride com$ort%

Semi.Active Susension is !ased on the s('.hoo( theor'% This theor' has !een esta!lished !' 0r%Jarno in =UD% He considered# i$ the damer is hoo(ed to the a!solute a)is# vi!ration o$ the

mass "ill !e most e$$ectivel' a!sor!ed%

And a!solute a)is loo(s li(e s('# so he named this theor' VS(' Hoo( Theor'% 7ut# in case o$

al'ing this theor' to the vehicle# there is no realit'% Instead o$ using s(' hoo( damer# he

considered to use varia!le damer as a s'stem "ith the same e$$ect% This idea is so called s('.

hoo( semi.active s'stem%

The !asic signals $or detecting the !od' u.do"n movement are acceleration sensors mounted on

the srung "eight% In addition# the in$ormation $rom the steering sensor# T6S# !ra(e s"itch# vehicle

seed sensor are used $or the vehicle maneuver% According to the in$ormation $rom the sensors#

ECS control module decides the daming $orce o$ each shoc( a!sor!er !' managing the al'ing

current to the roortional solenoid valve attached on the shoc( a!sor!er%

ECS s'stem has an ECS select s"itch% So drivers can choose the riding $eeling !et"een a normal

mode or a sort mode%

SKY HOOK SYSTEM

Semi.active susension is !ased on the S('.Hoo( Theor'% This theor' has !een esta!lished !' 0r%





Jarno in =UD% He considered# i$ a damer is hoo(ed to an a!solute a)is# vi!ration o$ the mass

"ill !e most e$$ectivel' a!sor!ed% And a!solute a)is loo(s li(e s('# so he named this theor' VS('.

Hoo( Theor'% Ho"ever# the concet o$ a!solute a)is li(e s(' "as ver' hard to !e alica!le to the

vehicle susension% Instead o$ using a S('.Hoo( damer# he considered to use varia!le damer as

a s'stem "ith the same e$$ect% This idea is so called S('.Hoo( Semi.active s'stem%

According to this theor'# daming $orce o$ varia!le damer should !e the same as that o$ S('.Hoo(

damer% Coe$$icient C= in $ormula />1 should !e controlled $or this urose%

7ut in case that varia!le daming $orce is onl' availa!le to the oosite direction to that o$ the S('.

Hoo( damer as sho"n in $ormula /B1# daming $orce should !e controlled to minimum or 8ero% He

has roved this theor' through simulation that almost similar daming e$$ect is attained as active

susension%


:Characteristics o$ reverse damer;




Semi.active susension incororates the S('.Hoo( theor' /or S('.Hoo( damer1 as an susension

control concet% S('.Hoo( damer to restrict a vehicle oscillation !' the irregular road sur$ace is

em!odied !' using a continuous varia!le damer% That is# "hen the vehicle !od' moves do"n /X=

@1# comression stro(e /X= . X@ @1 o$ a varia!le damer is getting harder# conversel' re!ound

stro(e /X= . X@ Y @1 is getting so$ter% Ho"ever "hen the vehicle !od' moves u /X= Y @1

comression stro(e /X= . X@ @1 o$ a varia!le damer is getting so$ter# conversel' re!ound stro(e

/X= . X@ Y @1 is getting harder%

A 5everse t'e shoc( a!sor!er /one o$ continuous varia!le damers1 incororated $or Semi.active

susension uses a srung "eight velocit'% When X= Y @# H9S mode /5e!ound* Hard# Comression*

So$t1 is alied# "hen X= @# S9H mode /5e!ound* So$t# Comression* Hard1 is alied !'

controlling the alied current o$ the varia!le damer%

This icture sho"s that a varia!le damer /reverse damer1 o$ ECS s'stem rovides less

movement at !um' road comaring "ith a conventional daming s'stem%

SKY HOOK DAMPER ADVANTAGE OF REVERSE TYPE DAMPER

7ased on Jarno theor'# control mode o$ daming $orce is classi$ied into D cases "ith the

com!ination o$ !od' movement and relative seed !et"een !od' and "heel%

To select otimum mode in normal varia!le damer s'stem# in$ormation $rom G sensor at srung

mass and height sensor is re3uired% Semi.active damer "as designed to have uni3ue daming

characteristics in order to eliminate height sensor% This characteristic is e)lained in this chart#

namel'① re!ound rocess has hard osition "hile comression rocess has so$t osition and ②

re!ound rocess has so$t osition "hile comression rocess has hard osition%

As a result# "e can control the s'stem onl' $rom the in$ormation o$ G sensor% We named this

s'stem as Vreverse t'e daming s'stem or H9S t'e%





SYSTEM PERFORMANCE

-irst o$ all# "e "ould li(e to e)lain the outline and the s'stem er$ormance o$ our ne" generation

semi.active susension s'stem%

=1 7od' control6itching and !ouncing movement are controlled in relate to the vertical acceleration sensor% 5oll#

dive# s3uat movements are controlled in relate to the seed sensor# the steering angle sensor and

the !ra(e s"itch signals%

>1 0aming $orce control

In order to e)ecute these !od' control reverse daming $orce t'e is adoted to suite to the s('

hoo( theor'% It can control the daming $orce continuousl' $rom H9S osition to S9H osition%

B 1 Actuator

The actuator is a roortional solenoid valve attached on the side o$ the shoc( a!sor!er% The

resonse time $rom H9S osition to S9H osition# or $rom S9H osition to H9S osition is less than B@

ms% The oerating current o$ the roortional solenoid $or this control is less than =%BA%

CONSTRUCTION AND OPERATION OF SHOCK

ABSORBER

Chonan Technical Service Training Center 36:Construction o$ Shoc( A!sor!er;




All h'draulic shoc( a!sor!ers "or( !' the rincile o$

converting (inetic energ' /movement1 into thermal

energ' /heat1% -or that urose# $luid in the shoc(

a!sor!er is $orced to $lo" through restricted outlets and

valve s'stems# thus generating h'draulic resistance% A

shoc( a!sor!er /damer1 can !e comressed and

e)tendedO the so.called !um stro(e and re!ound stro(e%

B'5 !"#e

When the iston rod is ushed in# oil $lo"s "ithout

resistance $rom !elo" the iston through the ori$ices o$

iston valve% Simultaneousl'# a 3uantit' o$ oil is dislaced

!' the volume o$ the rod entering the c'linder% This

volume o$ oil is $orced to $lo" through the !od' valve into

the reservoir tu!e /$illed "ith air /= !ar1 or nitrogen gas

/D. !ar11% The resistance# encountered !' the oil on

assing through the !od' valve# generates the !um

daming%

Re8#'$ !"#e

When the iston rod is ulled out# the oil a!ove the iston is ressuri8ed and $orced to $lo" through

the iston% The resistance# encountered !' the oil on assing through the iston# generates the

re!ound daming% Simultaneousl'# some oil $lo"s !ac(# "ithout resistance# $rom the reservoir tu!ethrough the !od' valve to the lo"er art o$ the c'linder to comensate $or the volume o$ the iston

rod emerging $rom the c'linder%

ECS SHOCK ABSORBER

The daming $orce control valve is located

on the side o$ the shoc( a!sor!er !'

"hich the uer room o$ iston is

connected to the lo"er room o$ the istonthrough the middle assage room% The

si8e o$ ori$ice inside the varia!le control

valve changes according to alied

current resulting in varia!le daming

$orce%

In re!ound rocess# the chec( valve o$ iston closes itsel$ and oil $lo"s $rom uer room o$ the

iston to the control valve through a hole located uer side o$ the inner tu!e and the middle room%

When oil asses the control valve# it $lo"s to lo"er room o$ the iston through the middle room and

a hole located at the lo"er side o$ the inner tu!e% At the same time# oil is sulied $rom reservoir to


:ECS Shoc( A!sor!er* simle model;




lo"er room o$ iston through the suction valve o$ !od'%

In jouncing rocess# the one "a' valve o$ !od' closes and the oil $lo"s $rom the lo"er room o$ the

iston to the uer room# rod volume o$ oil $lo"s to a hole o$ lo"er side o$ inner tu!e# middle room#

control valve# and returns to reservoir room%

DAMPING FORCE CHARACTERISTICS

As the daming $orce characteristics $igured in this schematic# the shoc( a!sor!er has the reverse

daming $orce t'e%

The inut current o$ the roortional solenoid is !et"een @%B A o$ H9S osition and =%B A o$ S9H

osition% The current o$ S9S osition is @% A% When the actuator $ailure "ith @ A condition# the

osition turns to H9S osition% When the current is going do"n $rom @% A o$ S9S osition# the

re!ound side daming $orce increase the ori$ice characteristic and ma(e the !lo" o$$ oint higher%

When the current is going u $orm @% A# the jouncing side daming $orce increase the ori$icecharacteristic and ma(e the !lo" o$$ oint higher%

SEMI-ACTIVE CONTROL

The amount of Ride Control which manages the vertical movement of the vehcle is decided on the

basis of 3 acceleration sensors and a vehicle speed sensor.

Anti-Roll Control which manages the movement of lateral direction is done by signals of a steering

wheel sensor and a vehicle speed sensor.

Anti-Dive Control uses Brake On/Off signal and the vehicle speed and Anti-Squat Control is done

by TPS signal.

Speed Sensitive Control changes overall damping force in proportion to the vehicle speed.

By the information detected by sensors, ECS control module applied corresponding current to the

solenoids of shock absorber.





BODY CONTROL

6itching and !ouncing movements are controlled in relate to the vertical acceleration sensor signal%

5oll# dive# s3uat movements are controlled in relate to the seed sensor# the steering sensor and

!ra(e s"itch and throttle osition sensor% The $undamental concet o$ this s'stem logic is as

$ollo"s

. Calculate the a!solute unsrung seed !' integrating the outut o$ acceleration sensor on the

unsrung%

. Then decide target daming $orce deend uon the roortional rate o$ the a!solute seed# and

control the actuator outut accordingl'%

RIDE CONTROL

7) R#7 ':e5e$! #$!"#l

This urose is imrovement o$ control e$$ect and reventive o$ ride com$ort go "orse% 5oad

judgement condition use acceleration sensor and EC, change the arameters use this result%

Zudgement result is decided !' acceleration sensor signal o$ -5 and -L% There is no riorit'

!et"een -5 and -L%

Sensor * AG Sensor /-5#-L1

8) A$!%8#'$e <ee 87 C#$!"#l

This urose is control o$ !ounce% Add $ront and rear !od' velocities# EC, control the daming

$orces in roortion to this result%


Ride Control

Logic

Speed Sensitive

Control Logic

Anti-Roll

Control Logic

Anti-Dive

Control Logic

Anti-Squat

Control Logic

Ride Control

Logic

Speed Sensitive

Control Logic

Anti-Roll

Control Logic

Anti-Dive

Control Logic

Anti-Squat

Control Logic

Ride Control

Logic

Speed Sensitive

Control Logic

Anti-Roll

Control Logic

Anti-Dive

Control Logic

Anti-Squat

Control Logic

FR G-Sensor

FL G-Sensor

RR G-Sensor

Distribution

to wheels

4 Sol.

Actuators

ehicle Speed

Steering Angle

!ra"e #n$#%

&'S




) A$!%%!4 <ee 87 C#$!"#l

This urose is control o$ itching% Su!tract $ront and rear !od' velocities# EC, control the

daming $orces in roortion to this result%

) A$!%"#ll <ee 87 C#$!"#l

This urose is control o$ roll% This urose is control o$ roll %Su!tract right and le$t !od'

velocities# EC, control the daming $orces in roortion to this result%

HANDLING

7) A$!%"#ll <ee <#"97" C#$!"#l

This urose is control o$ roll% ,se steering and seed sensor# EC, control the daming $orces

use these sensors oututs%

0aming control* 5e!ound Hard /H9S1

8) A$!%%6e C#$!"#l

This urose is control o$ dive% ,se !ra(e s"itch and seed sensor# EC, control the daming

$orces use these sensors oututs%

0aming control* -ront Comession Hard /S9H1# 5ear 5e!ound Hard /H9S1

) A$!%'7! C#$!"#l

This urose is control o$ s3uat% Throttle osition sensor outut is more than standard# EC,

control the daming $orces V$ront*hard9re!ound# rear*so$t9re!ound% And it $inish a$ter a constant

time ass%

0aming control* -ront 5e!ound Hard /H9S1# 5ear Comression Hard /S9H1

) H%:4 ee !78%l%!=

This urose is control o$ high seed sta!ilit'% ,se seed sensor# EC, control the daming

$orces use these sensors oututs%





CONSTRUCTION OF SEMI-ACTIVE ECS

SYSTEM SCHEMATIC

LOCATION OF COMPONENTS





LOCATION OF ECSCM

INPUTS & OUTPUTS


INPUTS OUTPUTS




INPUTS

*) ECS CONTROL MODULE POWER SUPPLY

- IG > /B@A# ECSCM o"er1* i$ !lo"n out Engine sto# Communication $ailure

- 7 /=A# ECS solenoid rela' o"er1* i$ !lo"n out C>=>D/Actuator rela'1

- IG > /=@A# ECSCM & Cluster o"er1* i$ !lo"n out Communication $ailure

+) ALTERNATOR L TERMINAL

a% Alication

The ECS control module detects the charging current

using a generator terminal +L+% ,on the normal outut

o$ generator charging current a$ter ignition.on# the ECS

ECM "ill oerate the ECS s'stem normall'% I$ the

generator outut voltage is lo"er !' loosen !elt or

generator $ailure# actuator rela' is o$$ and ECS oeration"ill sto%

!% Seci$ication

. 4utut oltage at Engine Sto* Ma)

. 4utut oltage at Engine 5un* =@ Min


:Normal; :Lo" voltage;




) BRAKE SWITCH

7ra(e s"itch signal is used as the inut signal $or anti.dive control% 7ra(e s"itch signal line is

connected in arallel "ith the sto lam# and used to determine driver2s !ra(e oeration condition%

a% Alication

Inut signal $or anti.dive control

!% Seci$ication

. Stead' state characteristic* Normal oen

/Close at utting on the !ra(e1

. oltage dro* @%> MAX /at @%=>A1

. No 0TC code

.) ECS MODE SWITCH (SPORT/NORMAL SWITCH)

The ECS mode s"itch is used to select sort or normal

mode deending on the running condition%

Se%<%7!%#$

. S"itch t'e* Normal oen/Sel$ return1

. S"itch on /S645T1* @%> or less

. S"itch o$$ /N45MAL1* D% or more


R

R

D C

+5V

BRAKE

:ECS s"itch;




0) VEHICLE SPEED SENSOR

The ECSCM "ill use the vehicle seed sensor signal% The seed signal is used to control handling#

anti.dive# anti.roll high seed running sta!ilit'% Seed sensor is made o$ hall element# "hich is

located in the transa)le% 5otor "ith D rojections is located inside the sensor# "ill rotate to generatethe hall e$$ect# and outut the digital ulse%

a% ,sage

Inut signal $or anti.dive control# anti.roll control# high seed control

!% Seci$ication

. 5evolution * BU rm at @(m9h

. 6ulse9= revolution * D 6ulse9 = revolution

. oltage dro * =% Ma) at =%mA

. 4utut voltage* @#

. Chattering * = ms Ma)

. 0ut' ratio * @>@[

1) STEERING SENSOR

Steering sensor signal "ill !e used as the inut signal $or

anti.roll control% The steering sensor uses LE0 and hoto.

transistor# and sensor A /ST=1 and sensor 7 /ST>1 are

installed steering "heel% A Slit late is installed !et"een the

hoto.transistor and the LE0% The slit late has D holes# soit "ill rotate "hen the steering "heel rotates% The hoto.

transistor oerates deending on light that "ill ass the slit

late holes# and the digital ulse signal is outut% ECM "ill

use the signal to $igure the steering "heel seed and angle%

a% Alication

. Inut signal $or anti.roll control

. Location* Inside steering "heel

. Calculate the steering amount and direction

. B Inut Signals /ST =# ST ># ST N1

. ST N detects the neutral osition o$ steering "heel

!% Seci$ication

. Sensor t'e * 6hoto interrut t'e

. Sensor outut t'e * 4en Collector T'e

. 4utut ulse 3uantit' *Dulse /6ulse c'cle ?1

. 0ut' ratio * @=@[

. 6hase di$$erence o$ oututs * >%@ @%?





. Sul' voltage *IGN=/R=1

. 4utut voltage *=%B≤4L≤>%@# B%B≤4H ≤D%@

.Ma)imum rotational velocit' * =#@@?9s

c% 4erationThere is a hall late !et"een the hoto.controller LE0 and the hoto transistor% As the hole late

rotates "ith steering "heel rotation# electrical signal "ill !e generated deending on "hether the

LE0 light asses through the late to the hoto.transistor or not% The signal is the steering "heel

oeration angular velocit' and used to detect the steering "heel turning direction%

- 6hoto.transistor on* sensor outut @% or less

- 6hoto.transistor o$$* sensor outut aro)% B%

d%

Steering sensor outut

e% Current data "hen the sensor is oen


:4utut voltage "hile turning le$t;




2) THROTTLE POSITION SENSOR

The throttle osition sensor signal is the inut $or anti.s3uat control% ,on the vehicle start.u#

driver "ill deress the accelerator edal# the throttle osition sensor signal "ill rovide the seed

change and the change amount to detect sudden acceleration% The signal is used to determine the

s3uat daming $orce varia!le solenoid valve iston% T6S is an analogue sensor using a varia!le

resistance% The engine ECM "ill convert the analogue signal inut $rom T6S to digital ulse /6WM1

signal to rovide other s'stems% Then the ECSCM "ill receive the digital /6WM1 signal inut%

a% Seci$ication

. 4utut signal t'e* 6WM outut

. 4utut signal dut'* ==[/angle @?1 R =[/angle @?1

. 6WM $re3uenc'* =@@H8

!% ,sage * Anti.s3uat control





c% Sensor circuit and outut characteristics

d% 4utut signal

3) ACCELERATION SENSOR (G-SENSOR)

In order to detect a lane# at least B oints are re3uired%

There are B G sensors* $ront right# $ront le$t and rear%

ECSCM "ill detect the G sensor outut voltage and

determine the vertical movement o$ the vehicle% ECSCM"ill use the G sensor inut signal as the main signal to

control the anti.!ounce# anti.itch# and anti.roll%

a% Alication* Main signal $or driving $eeling /BEA1

!% Seci$ication

. Inut oltage* @%>

. 4utut oltage* @% R D%D

. Nominal Sensitivit'* >%@9g


Se$#"

#$$e!#"

:Acceleration Sensor;




. 5ange* =g R =g

. 4erating Temerature* D@ R => ℃

c% Sensor location /-5 sensor# -L sensor# 5ear sensor1

d% Sensor IC construction

e% Sen

sor

circuit and sensor outut characteristics





$% Current data & sensor outut


JA! l7$e '"<7e

JA! 7"#'$ .0

JA! 7"#'$




OUTPUTS

*) ACTUATOR RELAY


JW4e$ !4e e$#" % #e$




ECS actuator rela' oeration "ill !e controlled !' the ECSCM% ,on the ECS actuator rela'

oeration# current "ill !e rovided to the daming $orce varia!le solenoid valve via ECSCM internal

circuit% When the generator terminal +L+ voltage dros to +L4W+ "hile running# ECSCM "ill 3uit the

actuator rela' oeration%

a% Alication

Actuator rela' is activated !' ECS

control module and sulies o"er to

the roortional solenoid%

!% Seci$ication

. Consumtion 6o"er* =%W /at => 1

. 4erating Temerature* D@ R =@@℃

. Control Current* =@ mA

c% -unctions

. EC, ground control

. While ECS control* @

. 4ut o$ ECS control* =>

d% Current data "hen the rela' is o$$

+) ECS LAMP

ECS indicator lam is located on the instrument anel#

and "ill !e on !' selecting the sort mode or !lin( i$

the ECS s'stem $ails% ECSCM controls the ground

terminal "hen the s"itch signal is inut or "hen the

s'stem $ailure is detected%

a% Seci$ication

. T'e* LE0


:Actuator rela' circuit;

:ECS lam;




. Consumtion 6o"er* Ma) >mA /at => 1

!% Alication

ECS lam comes on "hen sort mode is

selected or "hen there is a $ailure on thes'stem%

c% Lam oeration

. Normal* 4--# Sort* 4N# -ailure* -lashing

d% ECS Control Mode & Lam Control Seci$ication

. While running normal# the lam is turned on9o$$ !' s"itch% 7ut the lam is on in B seconds a$ter

control module started%

a1 Select Sort* ECS Lam 4N

!1 Select normal* ECS Lam 4--

. 0etecting trou!les

* I$ some trou!le is detected# a diagnosis num!er coing "ith the trou!le is recorded% AT the

same time VSort lam goes on and o$$% I$ a trou!le is detected# the lam starts going on and o$$%

. Sort lam turns on "hile HI.SCAN communication

e% 4utut signal o$ ECS lam





) SOLENOID VALVE (PROPORTIONAL TYPE)

Alied current to the daming $orce varia!le solenoid valve "ill !e controlled !' the ECSCM%

0eending on the current alied# the sool valve in the actuator "ill move to change $lo"ing route

and lead to the daming $orce variation%

a% Alication* Main signal $or driving $eeling

!% Seci$ication

. 4utut current range * @%BA R =%BA

=1 5e!ound Hard 9 Comression So$t * @%BA

>1 5e!ound So$t 9 Comression So$t * @%A

B1 5e!ound So$t 9 Comression Hard * =%BA

. 5ated voltage * =>

. 4erating voltage * =@ R =

. 6WM $re3uenc' * @@H8

c% Location





d% Construction

In the case o$ re!ound rocess# the rocedure to change daming $orce hard isO

. 5educe the current o$ solenoid actuator then the ilot sool moves to right side and cho(e the

area o$ control ort# so that the daming $orce o$ ori$ice control increases and the room

ressure !ehind the main valve is increased# As the result# the daming $orce turn to hard due





to increase o$ oening ressure o$ main valve%

The rocedure to change daming $orce so$t isO

. Increase the current o$ solenoid actuator then the ilot sool moves to le$t side and oen the

area o$ control ort# oil $lo"s !oth through the ori$ice o$ the re!ound side main valve and thecontrol ort o$ the ilot sool# so that the daming $orce o$ ori$ice control reduce# and same time

the room ressure !ehind the main valve decrease due to the ressure dro o$ the main valve

ori$ice# then the !lo" o$$ oint o$ main valve moves to lo"er side# As a result# the daming

$orce turn to so$t% In the case o$ jouncing rocess# i$ 'ou "ant to ma(e it hard# the current

should !e increased# i$ 'ou "ant to ma(e it so$t# the current should !e decreased%

e% 4eration /HA509S4-T mode1

When the alied current dros !elo" @%A# the sool valve moves to the le$t as the $orce o$ the

sring against the sool valve overcomes the magnetic $orce o$ the solenoid coil%

0uring the comression stro(e# the oil $lo"s $rom the comression cham!er to the !ase cham!er

$reel' !ecause the sool valve remains oen% As a result# the comression stro(e remains so$t%

As the sool valve moves le$t# the oening $or the re!ound cham!er to the !ase cham!er gets

smaller restricting oil $lo"% When alied current reaches @%BA# the oil ath is closed comletel'

and the re!ound stro(e !ecomes the hardest%

$% 4eration /S4-T9HA50 mode1

I$ the alied current increases a!ove @%A# the sool valve moves to the right decreasing oil $lo"

to the comression cham!er% When current increases to =%BA# the oening !et"een the

comression cham!er and the !ase cham!er is closed comletel'% At =%BA# the comressionstro(e !ecomes the hardest%

0uring the re!ound stro(e# the oil ath $rom the re!ound cham!er to the !ase cham!er through

the sool valve remains oen# so the re!ound stro(e remains so$t%

g% 4eration /S4-T9S4-T mode1

When the alied current is @%A# the daming $orce is so$t $or !oth comression and re!ound

stro(es% At @%A# the sool valve assage"a's are !oth oen% The oil inside the re!ound and the

comression cham!er $lo"s easil' to the !ase cham!er through the sool valve%

h% Current data & outut signal


\ While S4-T9HA50 control





\ While S4-T9S4-T control

\ While HA509S4-T control




DTC LIST





DIAGNOSTIC TROUBLE CODE

BATTERY? C***

a% 0iagnostic trou!le descrition

. Lo" voltage /Engine run1* Actuator oerating voltage is more than =U over >@sec%

. High voltage /Engine run1* Actuator oerating voltage is more than = over >sec%

!% Action to !e ta(en !' EC,* 5ela' 4--

c% Cancellation condition* ACG.L terminal outut changes Lo" to High /R=1 over =@@msec%

ALTERNATOR L TERMINAL? C**2 C**3

*) DTC? C**3 (L#9 6#l!7:e E$:%$e "'$)

a% 0iagnostic trou!le descrition* 4utut voltage is less than % over =@sec When the car

seed is more than D@(m9h

!% Action to !e ta(en !' EC,* rela' 4--

c% Cancellation condition* outut voltage is more than % over =@@msec%


N#; F7%l'"e C7$ell7!%#$ C#$%!%#$

= ACG L.Terminal ACG L.Terminal outut changes L4W to HIGH%

> Steering sensor Sensor outut voltage oututs normal value%

B Seed sensor Sensor outut more than B (m9h%

D

U

Sensor o"er source

voltage ACG L.Terminal outut changes L4W to HIGH%

0aming $orce change

actuator -5

0aming $orce change

actuator -L

=@0aming $orce change

actuator 55

==0aming $orce change

Actuator 5L

=> Actuator rela' ACG L.Terminal outut changes L4W to HIGH%

Acceleration sensor outut is "ithin the range $rom

>%.@%> to >%@%>%

ACG L.Terminal outut changes L4W to HIGH%

Acceleration sensor

/Including connector

disconnection1




+) DTC? C**2 (H%:4 6#l!7:e E$:%$e "'$)

a% 0iagnostic trou!le descrition* 4utut voltage is more than =% over =@@sec

!% Action to !e ta(en !' EC,* rela' 4--

c% Cancellation condition* outut voltage is less than = over =@@msec%

ACTUATOR RELAY ? C+*+.

a% 0iagnostic trou!le descrition

. Lo" voltage "hen on /Engine run1* Actuator oerating voltage is less than %@ over =@sec%

. High voltage "hen o$$ /Engine o$$1* Actuator oerating voltage is more than % over >sec

"hen Je' 4N%


c% Cancellation condition

. Lo" voltage "hen on /Engine run1* ACG.L terminal outut changes Lo" to High /R=1

over =@@msec%

. High voltage "hen o$$ /Engine o$$1* ACG.L terminal outut changes Lo" to High /R=1

and @ over =@@msec%

SPEED SENSOR ? C*+*+ (OPEN/SHORT ENGINE RUN)

a% 0iagnostic trou!le descrition* T6S outut dut' is more than D@[# and the outut less than B

(m9h over = minute%

!% Action to !e ta(en !' EC,* Hard9So$t /-* @%A# 5* @%B A1

c% Cancellation condition* The car seed is more than B(m9h over =@msec%

STEERING SENSOR ? C*+0 (OPEN/SHORT ENGINE RUN)

a% 0iagnostic trou!le descrition* Sensor outut voltage is less than @% or more than D%

over B@sec

!% Action to !e ta(en !' EC,* Sto the 5oll control

c% Cancellation condition* 5ight 4utut oltage is over =@msec%

ACCELERATION SENSOR (FR?C*+2 FL?C*+23 RR?C*+3*)

*) Oe$/S4#"! (E$:%$e "'$)

a% 0iagnostic trou!le descrition* Sensor outut is less than @% or more than D% $or >

minutes%

!% Action to !e ta(en !' EC,* Sto the 5ide control

c% Cancellation condition* Acceleration sensor outut is >%@%> over =@msec%





+) S%:$7l E""#" (E$:%$e "'$)

a% 0iagnostic trou!le descrition* Sensor outut (ees the same level at less than =% or

more than B%= $or > minutes

!% Action to !e ta(en !' EC,* Sto the 5ide control

c% Cancellation condition* Acceleration sensor outut is >%@%> over =@msec%

SOLENOID VALVE (FR?C++*1 FL?C++*+ RR?C+++. RL?C+++)

a% 0iagnostic trou!le descrition* Harness "ire is oen over B@sec


c% Cancellation condition* ACG.L terminal outut changes Lo" to High/R=1 over =@@msec%

WIRING DIAGRAM





\ 5e$er to the shomanual $or in assignment





SIMPLE WIRING DIAGRAM (Re<e" !# !4e 4#57$'7l <#" %$ 7%:$5e$!)

Documents

ECS and Wheel Aligment_KMC