p0634 is Transmission Control Module (TCM) Overtemperature.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. The TCM will remain off until the over temperature condition no longer exists. Perform the Transmission Fluid Check.Perform the Transmission Fluid Cooler Flushing and Flow Test to verify proper transmission oil cooler flow. inspect the transmission cooling system for the items list below and repair as necessary. If all the items test normal, replace the control solenoid (w/body and TCM) valve assembly:

• Obstructions in the airflow of the radiator or transmission cooler

• Kinked or damaged transmission fluid lines

• Damage to the transmission cooler,the dtc b2aaa does not come up as a valid code.post back with any other info.

Answered by brian 1 (expert)
1,100 answers provided

but have driven more than 200 miles it has npt showed up again so please tell me do i need to get checked
regards

Response from npslitt
3 questions asked

I would at least get it checked,you can stop at an GMC dealer,this vehicle is still under warrenty.

Answered by brian 1 (expert)
1,100 answers provided