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 Descriptor

DTC P025A 00: Fuel Pump Control Module Enable Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open or High Resistance

Short to Voltage

Signal Performance

Fuel Pump Control Module Enable

P025A

P025A

P025A

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Circuit/System Description

The engine control module (ECM) supplies a high voltage signal to the fuel pump control module (FPCM) when the ECM detects that the ignition is on. The high voltage signal from the ECM to the FPCM remains active for two seconds, unless the engine is in crank or run. While this signal is being received, the FPCM closes the ground switch of the fuel pump and also supplies a varying voltage to the fuel tank pump module in order to maintain the desired fuel rail pressure.

Conditions for Running the DTC

    • The ignition is ON.
    • Battery voltage is greater than 11.5 volts.

Conditions for Setting the DTC

The FPCM detects a fault on the fuel control enable signal circuit.

Action Taken When the DTC Sets

DTC P025A is an A type DTC.

Conditions for Clearing the DTC

DTC P025A is an A type DTC.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Fuel System Description

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

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

Important: Repair all U-codes before performing this diagnostic.

  1. Ignition OFF, disconnect the harness connectors at the ECM X1 and the FPCM.
  2. Ignition ON, test for 0 volts between the FPCM harness connector terminal 13 and ground.
  3. If greater than the specified voltage, test the fuel control enable signal circuit for a short to voltage.
  4. Ignition OFF, test for infinite resistance between the FPCM harness connector terminal 13 and ground.
  5. If less than the specified range, test the fuel control enable signal circuit for a short to ground.
  6. Ignition OFF, test for 1.0 ohm or less between the ECM harness connector X1 terminal 6 and FPCM harness connector terminal 13.
  7. If greater than the specified range, test the fuel control enable signal circuit for an open/high resistance.
  8. Reconnect the harness connectors at the ECM and the FPCM. Within 2 seconds of ignition ON, with a scan tool, verify that the Fuel Pump Command parameter displays ON.
  9. If the parameter does not display ON within the 2 seconds of ignition ON, replace the ECM.
  10. If all circuits test normal, replace the FPCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM or FPCM replacement, setup, and programming