2010 Cadillac CTS Sedan AWD V6-3.6L Page 1541
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
- Transmission Control Module (TCM) Overtemperature
The transmission control module (TCM) temperature sensor is located inside of the control solenoid valve assembly which has no serviceable parts.
The TCM monitors the TCM sensor for over temperature protection.
Conditions for Running the DTC
* Ignition voltage is between 8.6 volts or greater.
* The TCM temperature is between 0掳C (32掳F) and 170掳C (338掳F) for 0.25 seconds.
* DTC P0634 and has not set this ignition.
Conditions for Setting the DTC
The TCM has detected an internal temperature condition greater than 142掳C (288掳F) for 5 seconds.
Ignition voltage is equal to or greater than 18 volts and the TCM temperature is greater than 50掳C (122掳F) for 2 seconds.
Action Taken When the DTC Sets
* DTC P0634 is a Type A DTC.
* The TCM shifts to a default gear, shuts down, and turns OFF.
* The TCM disables TAP shift operation.
* The TCM enables torque management.
Conditions for Clearing the DTC
DTC P0634 is a Type A DTC.
During a road test, the TCM temperature should steadily increase to a normal operating temperature, then stabilize.
Description and Operation
Electronic Component Description (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Description and Operation/Electronic
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code
(DTC) Type Definitions)
Note: If DTC P0218 is set, diagnose that DTC first.
1. Perform the Transmission Fluid Level and Condition Check (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Testing
and Inspection/Initial Inspection and Diagnostic Overview/Transmission Fluid Level and Condition Check) to verify correct fluid level and
2. Operate the vehicle to normal engine temperature is reached. Verify with a scan tool the engine coolant temperature (ECT) sensor parameter
is less than 125掳C (257掳F).
瀚慖f greater than the specified value, refer to Symptoms - Engine Cooling (See: Engine, Cooling and Exhaust/Cooling System/Testing and
Inspection/Symptom Related Diagnostic Procedures/Symptoms - Engine Cooling).
3. Operate the vehicle till normal engine temperature is reached. Verify with a scan tool, the TCM temperature parameter is less than 142掳C