6T40/6T50 - Automatic Transmission

DTC P0601, P0603, P0604, or P062F

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

Note: DTCs P0601, P0603, P0604 or P062F could set in other control modules. Verify the DTCs are set in the transmission control module (TCM).

DTC P0601
- Control Module Read Only Memory Performance

DTC P0603
- Control Module Long Term Memory Reset

DTC P0604
- Control Module Random Access Memory Performance

DTC P062F
- Control Module Long Term Memory Performance

Circuit/System Description

This is an internal fault detection of the control solenoid valve assembly. This fault is handled inside the control solenoid valve assembly and no external circuits are involved.

Conditions for Running the DTC

P0601 or P0604

Runs continuously when TCM is powered up.

P0603

One time at TCM power up.

P062F

One time at TCM power down.

Conditions for Setting the DTC

P0601

TCM has detected a read only memory (ROM) checksum error 5 times.

P0603

TCM has detected a non-volatile memory checksum error at TCM powerup.

P0604

TCM has detected a random access memory (RAM) test error 5 times.

P062F

TCM has detected a non-volatile memory error during power-down.

Action Taken When the DTC Sets

* P0601, P0603, P0604, and P062F are Type A DTCs.

* TCM commands maximum line pressure.

* TCM forces the torque converter clutch (TCC) OFF.

* TCM inhibits TCC engagement.

* TCM freezes transmission adaptive functions.

* TCM commands the high side driver OFF.

* TCM defaults the transmission to 4th gear and reverse.

* Torque management is enabled.

* TCM inhibits neutral idle.

* TCM inhibits Tap Up/Down function.

* TCM inhibits manual shifting of forward gears.

Conditions for Clearing the DTC

P0601, P0603, P0604, and P062F are Type A DTCs.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics Electrical Diagrams

Connector End View Reference

* Component Connector End Views Outside Rearview Mirror - Driver

* Inline Harness Connector End Views X100

Description and Operation

* Transmission General Description Transmission General Description

* Transmission Component and System Description Transmission Component and System Description

* 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

Caution:
Before programming a control module, the following must be observed, or control module damage may occur:

* The TIS terminal, MDI, and/or scan tool must have the latest software.

* The vehicle battery must be fully charged. The battery voltage should be between 12-14 volts.

* The TIS terminal, MDI, and/or scan tool connections must be secure.

* A battery charger must NOT be connected to the battery when programming a control module.

1. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down.

2. Ignition ON.

3. Verify that DTC P0601, P0603, P0604, or P062F is not set.

• If any of the DTCs are set
Replace the Q8 Control Solenoid Valve Assembly.

• If none of the DTCs are set

4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

5. Verify the DTC does not set.

• If the DTC sets
Replace the Q8 Control Solenoid Valve Assembly.

• If the DTC does not set

6. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Perform the Transmission Adaptive Values Learn Transmission Adaptive Values Learn following all transmission repairs.

* Control Module References Control Module References for Control Solenoid Valve Assembly replacement, programming and setup.