P0669

DTC P0667, P0668, or P0669

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptors
DTC P0667
- Transmission Control Module (TCM) Temperature Sensor Performance

DTC P0668
- Transmission Control Module (TCM) Temperature Sensor Circuit Low Voltage

DTC P0669
- Transmission Control Module (TCM) Temperature Sensor Circuit High Voltage

Circuit/System Description

The transmission control module (TCM) temperature sensor is located inside of the control solenoid valve assembly which has no serviceable parts. The TCM temperature sensor provides the temperature of the TCM. This temperature reading is used in various diagnostic routines in the TCM software. This fault is handled inside the TCM and no external circuits are involved.

Conditions for Running the DTC

DTC P0667
* No other ECM or TCM DTCs are set.
* Engine speed is 400 RPM or greater for 5 seconds.
* Ignition voltage is 8.6 volts or greater for 5 seconds.
* Brake torque is not active.
* Engine torque signal is valid.
* Throttle position signal is valid.

DTC P0668 or P0669
* Engine speed is 400 RPM or greater for 5 seconds.
* Ignition voltage is 8.6 volts or greater for 5 seconds.

Conditions for Setting the DTC

P0667
* The difference between the transmission fluid temperature (TFT) and the TCM substrate temperature is greater than 20-50°C (36-90°F), depending on the average of the TFT, TCM substrate and TCM power up temperatures
* The difference between the TCM power up temperature and the TCM substrate temperature is greater than 8-10°C (14-18°F), depending on the average of the TFT, TCM substrate and TCM power up temperatures
* The above conditions have to be met for 5 minutes

P0668

The TCM internal temperature is -249°C (416°F) or greater for 4 seconds or more.

P0669

The TCM internal temperature is 249°C (480°F) or greater for 4 seconds or more.

Action Taken When the DTC Sets

* DTCs P0667, P0668, and P0669 are Type B DTCs.
* The TCM allows the vehicle to operate in transmission protection mode.
* The TCM defaults to an estimated value for the substrate temperature

Conditions for Clearing the DTC

DTCs P0667, P0668, and P0669 are Type B DTCs.

Diagnostic Aids

During a road test, the TCM temperature should steadily increase to a normal operating temperature, and then stabilize.

Reference Information
Schematic Reference

Automatic Transmission Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference

* Component Connector End Views (Connector End Views By Name)
* Inline Harness Connector End Views (Connector End Views By Number)

Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing For Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Description and Operation

* Electronic Component Description (Electronic Component Description)
* Transmission General Description (Transmission General Description)
* Transmission Component and System Description (Transmission Component and System Description)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)

Circuit/System Verification

1. Engine idling at normal operating temperature, verify the scan tool TCM Temperature parameter is between -247 and +247°C (-412 and +477°F).

• If not within the specified range, replace the Q8 control solenoid valve assembly.

2. Operate the vehicle at 64 km/h (40 mph) for 10 minutes. Monitor the TCM Temperature parameter and the Transmission Fluid Temperature parameter with a scan tool. The TCM Temperature parameter should increase by more than 2°C (3.5°F). Also, the TCM Temperature parameter and the Transmission Fluid Temperature parameter should be within 10°C (18°F) of each other.

• If the TCM Temperature parameter does not increase by more than 2°C (3.5°F) or the TCM Temperature parameter value is not within 10°C (18°F) of the Transmission Fluid Temperature parameter, then replace the Q8 control solenoid valve assembly.

3. After performing the above steps, then operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data. If the vehicle passes the Circuit/System Verification procedure then, refer to Testing for Intermittent Conditions and Poor Connections (Testing For Intermittent Conditions and Poor Connections).

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Control solenoid valve assembly replacement. Refer to Control Module References (Programming and Relearning) for replacement, setup, and programming.
* Perform the Service Fast Learn Adapts (Programming and Relearning) following all transmission related repairs.