AF40-6 (MDK) - Automatic Transmission

DTC P0601, P0602, P0603, or P0604

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

DTC P0601
- Control Module Read Only Memory Performance

DTC P0602
- Control Module Not Programmed

DTC P0603
- Control Module Long Term Memory Reset

DTC P0604
- Control Module Random Access Memory Performance

Circuit/System Description

This is an internal fault detection of the transmission control module (TCM). This fault is handled inside the TCM and no external circuits are involved.

Conditions for Running the DTC

The TCM runs the program to detect an internal condition at key ON. 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

P0601

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

P0602

The TCM has been unable to detected the 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.

Action Taken When the DTC Sets

P0601, P0602, P0603, P0604

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

* The TCM commands maximum line pressure.

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

* The TCM inhibits TCC engagement.

* The TCM freezes transmission adaptive functions.

* The TCM commands an immediate landing to 2nd gear.

Conditions for Clearing the DTC

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

Diagnostic Aids

Low voltage or momentary loss of voltage or ground to the ECM may cause a DTC to set. Verify the following:

* The battery cables are clean and tight, and the battery is fully charged.

* The TCM ground circuits do not have an open or high resistance.

* The TCM power circuits do not have an open, short to ground, or high resistance.

Reference Information

Description and Operation

Transmission Component and System Description Transmission Component and System Description

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. Engine running for at least 1 min.

2. Verify DTC P0601, P0602, P0603, or P0604 is not set.

• If the DTC is set

1. Ignition OFF for at least 30 s to allow for the complete shutdown of the TCM.

2. Program the K71 Transmission Control Module. Refer to Control Module References Control Module References

3. Verify DTC P0601, P0602, P0603, or P0604 is not set.

• If the DTC is set, perform the following steps:

* Ensure that all scan tool connections are secure.

* Ensure the programming equipment is operating correctly.

* Ensure the correct software and the correct calibration is used.

• If the DTC is not set

3. All OK.

• If the DTC resets

4. Replace the K71 Transmission Control Module.

Repair Instructions

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

* Refer to Control Module References Control Module References for TCM replacement, programming and setup.

* Perform the Transmission Adaptive Functions Transmission Adaptive Functions.