GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions 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 Long Term Memory Reset

DTC P0604: Control Module Random Access Memory (RAM)

DTC P0606: Control Module Internal Performance

DTC P062F: Control Module Long Term Memory Performance

Circuit/System Description

The internal fault detection is handled inside the fuel pump flow control module (FPCM). No external circuits are involved.

Conditions for Running the DTC

The FPCM runs the program to detect an internal fault when power up is commanded. 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 FPCM has detected an internal malfunction.

Action Taken When the DTC Sets

DTC P0601, P0602, P0603, P0604, P0606 and P062F are type A DTCs.

Conditions for Clearing the DTC

DTC P0601, P0602, P0603, P0604, P0606 and P062F are type A DTCs.

Reference Information

Description and Operation

Engine Controls Schematics

Electrical Information Reference

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

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Circuit/System Verification

Important: This DTC may be stored as a history DTC without affecting the operation of the module. If stored only as a history DTC and not retrieved as a current DTC, do not replace the module.

Verify that DTC P0602 are not set.

If the DTC is set, program the FPCM.

Verify that DTCs P0601, P0603, P0604, P0606, and P062F are not set.

If the DTCs are set, program the FPCM. If the DTCs reset, replace the FPCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for FPCM replacement, setup, and programming