Automatic Transmission - AF33-5

DTC P0601, P0602, P0603, or P0604

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
- Control Module Read Only Memory (ROM)

DTC P0602
- Control Module Not Programmed

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

DTC P0604
- Control Module Random Access Memory (RAM)

Circuit/System Description

This diagnostic applies to internal microprocessor integrity conditions within the transmission control module (TCM) system. This diagnostic also addresses if the TCM is not programmed.

Conditions for Running the DTC

* The ignition is ON, or the engine is operating.
* The DTCs run once an ignition cycle.

Conditions for Setting the DTC

P0601

The TCM detects that the checksum calculation does not match the expected checksum.

P0602

The TCM is identified as not programmed.

P0603

The TCM detects an incorrect copy of non-volatile memory.

P0604

The TCM detects a random access memory (RAM) read/write error.

Action Taken When the DTC Sets

P0601 and P0602
* DTCs P0601, and P0602 are Type A DTCs.
* The transmission will operate in 5th gear in D or M range, 2nd gear in L range.

P0603
* DTC P0603 is a Type A DTC.
* The TCM uses default EEPROM values.
* The TCM disables engine start.

P0604

DTC P0604 is a Type A DTC.

Conditions for Clearing the DTC

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

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. Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0602 does not fail this ignition cycle.

• If DTC P0602 failed this ignition, reprogram the TCM. Refer to Control Module References (Programming and Relearning). If DTC P0602 resets, replace the TCM.

2. Observe the DTC information with a scan tool. Verify that DTCs P0601, P0603, and P0604 do not set this ignition cycle.

• If any of the DTCs P0601, P0603, or P0604 are set this ignition cycle replace the TCM, refer to Transmission Control Module Removal (Overhaul) procedure and Transmission Control Module Installation (Overhaul) procedure.

Repair Instructions

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

Refer to Control Module References (Programming and Relearning) for TCM replacement, setup, and programming.