6T70/6T75 - Automatic Transmission

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
- Control Module Temperature Sensor Performance

DTC P0668
- Control Module Temperature Sensor Circuit Low Voltage

DTC P0669
- Control Module 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 components. The TCM temperature sensor provides the temperature of the TCM. This temperature reading is used in various shifting and diagnostic routines in the TCM software. This fault is handled inside the TCM and no external circuits are involved.

Conditions for Running the DTC

P0667
* DTC P0101, P0102, P0103, P0106, P0107, P0108, P0171, P0172, P0174, P0175, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308, P0401, P042E, P0658, P0667, P0668, P0669, P06AD, P06AE, P0712, P0713, P0716, P0717, P0722, P0723, P0962, P0963, P0966, P0967, P0970, P0971, P215C, P2720, P2721, P2729, or P2730 is not set.
* Brake torque is not active.
* The engine speed is 400 RPM or greater for 5 seconds.
* The ignition voltage is 8.6 volts or greater.
* The engine torque signal is valid.
* The throttle position signal is valid.

P0668
* DTC P0668 is not set.
* The engine speed is 400 RPM or greater for 5 seconds.
* The ignition voltage is 8.6 volts or greater.

P0669
* DTC P0669, P0716, P0717, P0722, or P0723 is not set.
* The engine speed is 400 RPM or greater for 5 seconds.
* The ignition voltage is 8.6 volts or greater.

Conditions for Setting the DTC

P0667
* The difference between the transmission fluid temperature (TFT) and 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 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 within a 6 minute period.

P0668

The TCM temperature is -249°C (-416°F) or lower for 1 minute.

P0669

The TCM temperature is 249°C (480°F) or greater for 1 minute.

Action Taken When the DTC Sets

* DTCs P0667, P0668, and P0669 are Type B DTCs.
* The TCM defaults the TCM substrate temperature to the TCM power up temperature.

Conditions for Clearing the DTC

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

Diagnostic Aids

The TCM temperature sensor is located inside of the control solenoid valve assembly and its output should resemble that of the TFT sensor output.

Reference Information
Connector End View Reference

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

Description and Operation

Electronic Component Description (Electronic Component Description) for control solenoid valve assembly
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)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

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 control solenoid valve assembly. Refer to Control Solenoid Valve and Transmission Control Module Assembly Replacement (6T70/6T75 - Automatic Transmission).

2. Operate the vehicle at 64 km/h (40 mph) for 10 minutes. Monitor the TCM Temperature and the Transmission Fluid Temperature parameters with a scan tool. The TCM Temperature parameter should increase by greater than 2°C (3.5°F). Also, the TCM Temperature and the Transmission Fluid Temperature parameters should be within 20°C (36°F) of each other.

• If the TCM Temperature parameter does not increase by greater than 2°C (3.5°F) or the TCM Temperature and Transmission Fluid Temperature parameters are not within 20°C (36°F), then replace the control solenoid valve assembly.

3. 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.

Repair Instructions

Note:
* Perform the Transmission Adaptive Values Learn (6T30/6T40/6T45/6T50 - Automatic Transmission) following all transmission related repairs.
* Before replacing the TCM, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection (Control Solenoid Valve and Transmission Control Module Assembly Inspection).

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

Control Module References (Programming and Relearning) for control solenoid valve assembly replacement, setup, and programming