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Allison WT Overview Featuresand I/O Functions
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Overview WT Control System
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Important Features of WT Transmissions
1. Autodetect: This feature automatically detects following
input signals at start of
ignition cycle
Throttle : TPS J1587 J1939
Engine water temp.sensor : Sensor J1939 J1587
Oil level sensor : Present Not Present
Retarder : Present Not Present
2. Adaptive Controls: Optimises the shift quality by monitoring
actual clutchengagement and making ongoing adjustments to improve
subsequent shifts. This feature
allows the transmission to quickly compensate for variations in
load,terrain and to adjust
for clutch wear & changes in engine power.
3. Automatic Throttle Position Calibration: When TPS used with
WT, Auto Cal
feature monitors and stores minimum & maximum position of
sensor. In doing so, ECUcan assign full throttle to max. position
and closed throttle to min.position of the sensor.
As linkage wears and adjustments of TPS changes, ECU will
automatically compensate
for the changes.
4. TRANS ID: The ECU is programmed in such a way that it can
identify theconfiguration of the transmission and select a
calibration which is appropriate for that
level of hardware. In case of mis-match, a diagnostic code is
registered.
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Important Features of WT Transmissions5. Check transmission
light.
6. Diagnostic data reader: Can be connected to the ECU, to
provide a self-checkof all systems in the transmission, with
trouble codes pin pointing any problem.
7. Maximum of 5 error codes can be seen in the shift selector
display without the
use of a diagnostic data reader.8. Safety features: Inhibiting
transmission on shifts from N to RANGE when
the engine is above idle.
9. Preventing shifts from FORWARD to REVERSE (or vice versa)
when vehicle
is moving.
10. Inhibits to prevent shifts in to gear when a door is
open.
11. ABS compatibility which allows the unit to drop lockup
clutch when ABS signal
is active.
12. The WT has hold positions in all ranges.
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Important Features of WT Transmissions
13. Reatrder capacity reduction based on engine coolant
temperature and
automatic pre-select downshifts for retarder models.
14. Retarder capacity reduction based on retarder oil
temperature.
15. Integration of retarder controls with vehicle braking
system.
16. Neutral start feature.
17. Reduced engine load at stop (RELS)
18. Secondary shift schedule.(Economy/Performance)
19. Automatic neutral when park brake activated.
20. Engine overspeed indicator
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Input and output functions - WT
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Example : Retarder Provision
