P0634
Powertrain Codes
P0634 - GMC - Transmission Control Module Overtemperature
Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
Possible Causes
- Obstructions in the airflow of the radiator or transmission cooler - Kinked or damaged transmission fluid lines - Damage to the transmission cooler
Tech Notes
Check transmission fluid level and condition and replaced fluid if necessary.
Description
The control solenoid (w/body and TCM) valve assembly has a built-in TCM temperature sensor to detect possible overtemperature conditions of the TCM. This fault indicates the TCM is in an overtemperature condition and the TCM has shut down to protect from possible heat damage to the TCM. TCM will remain off until the over temperature condition no longer exists.