Automatic Transmission - 6L50/6L80/6L90

DTC P0601-P0604 or P062F

Diagnostic Instructions

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

DTC Descriptors
DTC P0601
- Transmission Control Module (TCM) Read Only Memory (ROM)

DTC P0602
- Transmission Control Module (TCM) Not Programmed

DTC P0603
- Transmission Control Module (TCM) Long Term Memory Reset

DTC P0604
- Transmission Control Module (TCM) Random Access Memory (RAM)

DTC P062F
- Transmission Control Module (TCM) Long Term Memory Performance

Circuit/System Description

This is an internal fault detection of the control solenoid (w/body and TCM) valve assembly. This fault is carried out inside the control solenoid (w/body and TCM) valve assembly and no external circuits are involved.

Conditions for Running the DTC

* The control solenoid (w/body and TCM) valve assembly runs the program to detect an internal fault when the key is ON or the engine is running.
* Ignition voltage is between 8.6-18.0 volts - DTC P062F only.

Conditions for Setting the DTC

P0601

The read only memory (ROM) test has failed 5 or more times.

P0602

The transmission control module (TCM) has detected no start program.

P0603

The TCM has detected a memory checksum error.

P0604

The TCM random access memory (RAM) test has failed 5 or more times.

P062F

The TCM has detected non-volatile memory is incorrect during power-down.

Action Taken When the DTC Sets

* DTCs P0601, P0602, P0603, P0604, and P062F are Type A DTCs.
* The TCM shifts to a default gear, shuts down, and turns OFF.

Conditions for Clearing the DTC

DTCs P0601, P0602, P0603, P0604, and P062F are Type A DTCs.

Diagnostic Aids

When attempting to set TCM internal DTCs let the engine run for at least 1 minute and then shut the engine off for at least 30 seconds. Following this procedure will allow a complete TCM shutdown. Reprogram the TCM and retest the DTC to see if the DTC resets.

Reference Information
Description and Operation

Electronic Component Description (Electronic Component Description)
DTC Type Reference

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

Circuit/System Verification

1. Start the engine.
2. Let the engine run for 1 minute, then shut the engine OFF for at least 30 seconds.
3. Retest for DTCs P0601, P0602, P0603, P0604, and P062F.

Circuit/System Testing

Reprogram the TCM and recheck for DTCs.

If the DTC resets, replace the control solenoid (w/body and TCM) valve assembly.

Repair Instructions

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

Perform the Service Fast Learn Adapts (Programming and Relearning) if internal transmission repairs are performed.