P0634 OBD-II: PCM/ECM/TCM Internal Temperature "A" Too High
P0634 Severity
Should you fix P0634 yourself?
Identifying an OBD code is just the start of a complete diagnostic routine. Most trouble codes are caused by a sensor reporting a value that is out of range. Just replacing a sensor may not fix underlying issues. Be sure to understand the code, the part or system in your car that the code refers to, and the risks of delaying professional repair.
Proper diagnosis will save you time and money on unnecessary repairs.
Urgent codes indicate immediate action is necessary. These are urgent and significant malfunctions that can cause severe damage to the vehicle or harm the driver and passengers.
What causes OBD-II fault code P0634?
Some vehicles place the Transmission Control Module (TCM) inside the Transmission. Due to the potential for heat buildup inside the transmission, the TCM is equipped with its own temperature sensor. If the TCM detects that it is getting too hot, it will set P0634. It will also place the vehicle into "Limp Home Mode", limiting the amount of power available, to prevent further damage.
Need a P0634 diagnosis? Trust our experts.
Tuffy Tire & Auto Service Center - Grandview
Excite Auto Repair & Towing
All In Auto Service
Tuffy Tire & Auto Service - Grove City
OBD II Fault Code
- OBD II P0634
OBD-II Code Transmission Control Module (TCM) failure is defined as a PCM/ECM/TCM Internal Temperature "A" Too High
Some vehicles place the Transmission Control Module (TCM) inside the Transmission. Due to the potential for heat buildup inside the transmission, the TCM is equipped with its own temperature sensor. If the TCM detects that it is getting too hot, it will set P0634. It will also place the vehicle into "Limp Home Mode", limiting the amount of power available, to prevent further damage.
Transmission Control Module (TCM) failure Symptoms
- Engine may enter limp home mode (reduced performance)
Common Problems That Trigger the P0634 Code
- Damaged transmission cooler
- Internal transmission failure
- Transmission Control Module (TCM) failure
- Wiring issue
Ask our experts about P0634.
RepairPal Car Genius™ is a free resource for vehicle owners seeking advice on maintenance, auto repair, shop inquiries, estimates, and finding a trustworthy repair shop in your area.
Call us at 877-913-1554
Available 9am – 6pm ET Monday through Friday