4L60-E/4L65-E/4L70-E - Automatic Transmission

DTC P0601-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 Descriptor
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

The internal fault detection is handled inside the transmission control module (TCM). No external circuits are involved.

Conditions for Running the DTC

The TCM runs the program to detect an internal fault when the engine is running. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range.

Conditions for Setting the DTC

The TCM has detected an internal malfunction.

Action Taken When the DTC Sets

P0601, P0604
* DTCs P0601, P0604 are Type A DTCs.
* The TCM commands soft landing to second gear.
* The TCM commands maximum line pressure.
* The TCM forces the TCC OFF.
* The TCM freezes transmission adaptive functions.

P0602, P0603, P062F
* DTCs P0602, P0603, P062F is a Type A DTCs.
* The TCM commands immediate landing to second gear.
* The TCM commands maximum line pressure.
* The TCM forces the TCC OFF.
* The TCM freezes transmission adaptive functions.

Conditions for Clearing the DTC

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

Diagnostic Aids

DTC P0602 indicates the TCM is not programmed.

Reference Information
Schematic Reference

Automatic Transmission Controls Schematics (4L60-E/4L65-E/4L70-E - Automatic Transmission)
Connector End View Reference

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

Transmission General Information (Transmission General Information)
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

Transmission Control Module Scan Tool Information (4L60-E) (Transmission Control Module Scan Tool Information (4L60-E))Transmission Control Module Scan Tool Information (6L45/6L50/6L80/6L90) (Transmission Control Module Scan Tool Information (6L45/6L50/6L80/6L90))Transmission Control Module Scan Tool Information (2ML70) (Transmission Control Module Scan Tool Information (2ML70))Transmission Control Module Scan Tool Information (Allison) (Transmission Control Module Scan Tool Information (Allison))

Circuit/System Verification

Verify that DTC P0602 is not set.

If DTC P0602 is set, program the TCM.

If DTC P0602 is not set, replace the TCM

Repair Instructions

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

Control Module References (Control Module References) for TCM replacement, setup, and programming.