For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | 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

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
TCM Temperature Sensor | P0668 | P0669 | -- | P0667

### Circuit/System Description

The transmission control module (TCM) temperature sensor is located inside of the control solenoid (w/body and TCM) valve assembly. The control solenoid (w/body and TCM) valve assembly has no serviceable parts. 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

• | No TFT DTCs P0711, P0712, or P0713.

• | No ISS DTCs P0716 or P0717.

• | No OSS DTCs P0722 or P0723.

• | The ignition voltage is between 9.0 volts and 19.0 volts.

• | The engine speed is greater than 500 RPM for 5 seconds or more.

• | DTC P0667 has not passed this key ON.

• | The TCM temperature is between -40 and +150°C (-40 and +302°F).

#### P0668

• | The ignition voltage is between 9.0 volts and 19.0 volts.

• | The engine speed is greater than 500 RPM for 5 seconds or more.

• | DTC P0668 has not failed this ignition cycle.

#### P0669

• | No ISS DTCs P0716 or P0717.

• | No OSS DTCs P0722 or P0723.

• | The ignition voltage is between 9.0 volts and 19.0 volts.

• | The engine speed is greater than 500 RPM for 5 seconds or more.

• | DTC P0669 has not failed this ignition cycle.

• | The transmission output shaft speed is 200 RPM or greater for 200 seconds or more.

• | The TCC slip speed is 120 RPM or greater for 200 seconds or more.

### Conditions for Setting the DTC

#### P0667 - Fail Case 1

• | Vehicle speed is 8 km/h (5 mph) or greater for 300 seconds cumulative.

• | Torque converter clutch (TCC) slip speed is greater than 150 RPM for 300 seconds cumulative.

• | The TCM internal temperature is between -40 and +76°C (-40 and +169°F).

• | The transmission fluid temperature (TFT) is 70°C (158°F) or greater.

• | The TCM internal temperature has changed by less than 2.0°C (3.6°F) in 300 seconds.

• | The TFT has increased by 55°C (99°F) since startup.

#### P0667 - Fail Case 2

• | Vehicle speed is 8 km/h (5 mph) or greater for 300 seconds cumulative.

• | TCC slip speed is greater than 150 RPM for 300 seconds cumulative.

• | The TCM internal temperature is between 76-150°C (168-302°F).

• | The TCM internal temperature has changed by less than 2.0°C (3.6°F) in 300 seconds.

• | The TFT is 70°C (158°F) or greater.

• | The TFT has increased by 55°C (99°F) since startup.

#### P0667 - Fail Case 3

The TCM internal temperature changes by 20°C (36°F) or greater 5 times over 7 seconds.

#### P0668

The TCM internal temperature is 254°C (489°F) or greater for 12.75 seconds or more.

#### P0669

The TCM internal temperature is -254°C (-425°F) or less for 12.75 seconds or more.

### Action Taken When the DTC Sets

• | DTCs P0667, P0668, and P0669 are Type C DTCs.

• | The TCM allows the vehicle to operate in transmission protection mode.

### Conditions for Clearing the DTC

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

### Diagnostic Aids

The TCM temperature sensor is located inside of the control solenoid (w/body and TCM) valve assembly and its output should resemble that of the transmission fluid temperature (TFT) sensor output.

### Reference Information

#### Description and Operation

• | Transmission General Description

• | Transmission Component and System Description

• | Electronic Component Description

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

1. Engine running. Verify the scan tool TCM Temperature parameter is between -254 and +254°C (-425 and +489°F).

⇒ | If not within the specified range, replace the control solenoid (w/body and TCM) valve assembly.

2. Operate the vehicle at 64 km/h (40 mph) for 10 minutes, verify the scan tool TCM Temperature parameter varies by more than 2°C (5°F) to verify that the sensor is not stuck.

⇒ | If not within the specified range, replace the control solenoid (w/body and TCM) 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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

| Important: Before replacing the TCM, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection.

• | Refer to Control Module References for control solenoid (w/body and TCM) valve assembly replacement, setup, and programming.

• | Perform the Service Fast Learn Adapts following all transmission related repairs.