How to Reset Transmission Control Module?

[AlexMahon]

For posterity - internet research - Re-set Transmission Control Module (TCM) (2008 Yukon L76/4L70E):


Method #1:

- Disconnect both battery poles (negative first);

- Leave disconnected for 30 minutes minimum;

- Reconnect battery poles;

- Start;

- Check dash indications;

- Road test for smooth shifting.



Method #2:

- Disconnect both battery poles (negative first);

- Disconnect TCM (blue multi-pin connector driver side of ENG); leave disconnected for 30 minutes minimum; reconnect TCM.

- Reconnect battery poles;

- Start;

- Check dash indications;

- Road test for smooth shifting.



Method #3; Reset TCM:

- Ignition switch to ON (no start);

- Dash light ON

- Press full down on gas pedal; hold full down for minimum 15 seconds;

- Ignition switch to OFF;

- Release gas pedal;

- Wait approx. 5 minutes;

- Start ENG;

- Check dash indications;

- Road test for smooth shifting;

- Owner: 20-30 minute drive for TCM to re-learn driver habits;



Method #4: R&R TCM:

- Preferred: GM/ACDelco #24252114; approx. $148 + $25 core; Other: Dorman #599-120; approx. $150 + $50
core;

- Start ENG;

- Check dash indications;

- Road test for smooth shifting;

- Owner: 20-30 minute drive for TCM to re-learn driver habits.

 

[Mudsport96]

Yeah not needed for the older vehicles