2ML70 - Automatic Transmission

DTC P06AC, P06AD, or P06AE

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 Descriptor
DTC P06AC
- Transmission Control Module (TCM) Power Up Temperature Sensor Performance

DTC P06AD
- Transmission Control Module (TCM) Power Up Temperature Sensor Circuit Low Voltage

DTC P06AE
- Transmission Control Module (TCM) Power Up Temperature Sensor Circuit High Voltage

Circuit/System Description

The transmission control module (TCM) power up temperature sensor is located inside of the control solenoid valve assembly and is not serviced separately. The TCM power up temperature sensor provides the temperature of the TCM when the TCM power is on. This temperature reading is used in various shifting and diagnostic routines and also to protect the control solenoid valve assembly and TCM. This fault is handled inside the TCM and no external circuits are involved.

Conditions for Running the DTC

* The engine is running for 5 seconds.
* The vehicle speed signal is valid for 5 seconds.

P06AC
* DTC P0721, P0722, P0723, P215C, P0658, P0668, P0669, P0712, P0713, P06AD, or P06AE is not set.
* The transmission is not in Park or Neutral.
* The vehicle speed signal is valid for 5 seconds.

P06AD
* DTC P0721, P0722, P0723, or P215C is not set.
* The estimated motor power loss is greater than or equal to 0.4 Kw for 200 seconds.

Conditions for Setting the DTC

P06AC
* The difference between the TCM power up and the TCM substrate temperature is greater than 8-10°C (14-18°F) depending on the average of the Trans. Fluid Temp., TCM substrate, and TCM power up temperatures.
* The difference between the TCM power up and the Trans. Fluid Temp. temperature is greater than 20-50°C (36-90°F), depending on the average of the Trans. Fluid Temp., TCM substrate, and TCM power up temperatures.
* The above conditions have to be met for 5 minutes within a 7 minute period.

P06AD

The TCM power up temperature is -59°C (-74°F) or less for 1 minute.

P06AE

The TCM power up temperature is 164°C (328°F) or greater for 1 minute.

Action Taken When the DTC Sets

* DTCs P06AC, P06AD, and P06AE are Type B DTCs.
* The TCM defaults the TCM power up temperature to the TCM substrate temperature with an offset value.

Conditions for Clearing the DTC

DTCs P06AC, P06AD, and P06AE are Type B DTCs.

Diagnostic Aids

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

Reference Information
Schematic Reference

Automatic Transmission Controls Schematics (2ML70 - Automatic Transmission)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

Electronic Component Description (Electronic Component Description)
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 (Control Module References)for scan tool information

Circuit/System Verification

1. Operate the vehicle at 64 km/h (40 mph) for 10 minutes. Monitor the TCM Power-Up Temperature parameter and the TCM Temperature parameter with a scan tool. The TCM Power-Up Temperature parameter and the TCM Temperature parameter should be within 10°C (18°F) of each other.

• If the TCM Power-Up Temperature parameter is not within the specified value of the TCM Temperature parameter, then replace the Q8 control solenoid valve assembly.

2. 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 (Verification Tests) after completing the diagnostic procedure.

Control solenoid valve assembly replacement. Refer to Control Module References (Control Module References) for replacement, programming, and setup.