Transmission:Subject:

Applicati on:Issue Date:

Copyright © 2010 ATRA. All Rights Reserved.

Technical Bulleti n # 13174L60E/4L80ETCC Surge or No TCC ApplyAll GM Models 1996 & UpApril, 2010

4L60E/4L80ETCC Surge or No TCC ApplyVehicle surging in and out of lock up at cruise or no lock up conditi on at all. The problem may beintermitt ent and more noti ceable on rough roads. When monitored on a scan tool the PCM will be commanding lockup on and off or there is no command for lockup what so ever. No transmission codes stored. Check for any engine related misfi re codes, P0300, P0301, P0302, P0303 or P0304. If there are no codes stored, monitor the TCC command status along with the engine misfi re counters. During misfi re counts the TCC will be commanded off (cycled), once the misfi re count reaches 100 (fi gure 1) there will be no TCC command at all. There sti ll may be no misfi re codes stored. GM has an updated PCM program to address this concern. The updated program changes the misfi re diagnosti c programming.

Note: On early model GM vehicles a bad Oxygen senor will prevent the PCM from going into “closed loop” or cycle the PCM in and out of closed loop. This problem will also cycle or prevent the TCC from applying.

MS • Page 1 of 1