Buick Regal: DTC P0601, P0602, P0603, or P0604

Diagnostic Instructions

• Perform the Diagnostic System Check prior to using this diagnostic procedure: Refer to Diagnostic System Check - Vehicle
• Review the description of Strategy Based Diagnosis: Strategy Based Diagnosis
• An overview of each diagnostic category can be found here: Refer to Diagnostic Procedure Instructions

DTC Descriptor

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

For an overview of the component/system, refer to Electronic Component Description This diagnostic applies to microprocessor integrity conditions within the control module. This diagnostic also checks if the control module is not programmed, or is programmed incorrectly.

Conditions for Running the DTC

Ignition Voltage=On

Frequency the DTC runs=Continuously - After the running conditions are met

Conditions for Setting the DTC

P0601

ROM Malfunction

P0602

Programming Malfunction

P0603

EEPROM Performance/Malfunction

P0604

RAM Malfunction

Actions Taken When the DTC Sets

DTCs listed in the DTC Descriptor Category=Type A DTC

Conditions for Clearing the DTC

DTCs listed in the DTC Descriptor Category=Type A DTC

Reference Information

Schematic: Reference

Refer to Automatic Transmission Controls Wiring Schematics

Connector End View: Reference

Refer to Component Connector End View Index

Component View: Reference

Refer to Disassembled Views

Electrical Information: Reference

• Refer to Circuit Testing
• Refer to Connector Repairs
• Refer to Testing for Intermittent Conditions and Poor Connections
• Refer to Wiring Repairs

DTC Type: Reference

Refer to Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool: Reference

Refer to Control Module: References

Circuit/System Verification

1. Ignition - On / Vehicle - In Service Mode

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

• If the DTC is set

1. Perform all necessary programming and setup procedures for the control module:K71 Transmission Control Module
2. Verify the DTC does not set.
   • If the DTC sets - Replace the component:K71 Transmission Control Module
   • Go to next step: If the DTC is not set
3. All OK.

• Go to next step: If the DTC is not set

3. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair: Refer to Diagnostic Repair Verification

For control module replacement, programming, and setup: Refer to Control Module: References

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