P025A

DTC P025A

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 Descriptor
DTC P025A
- Fuel Pump Control Module Enable Circuit

Diagnostic Fault Information





Circuit/System Description

The engine control module (ECM) supplies voltage to the fuel pump flow control module (FPCM) when the ECM detects that the ignition is on. The voltage from the ECM to the FPCM remains active for 2 seconds, unless the engine is in crank or run. While this voltage is being received, the FPCM 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.

Conditions for Setting the DTC

The serial data message from the ECM to the FPCM does not agree with the state of the control enable circuit voltage supplied from the ECM to the FPCM for more than 2 seconds.

Action Taken When the DTC Sets

DTC P025A is a Type B DTC.

Conditions for Clearing the DTC

DTC P025A is a Type B DTC.

Reference Information
Schematic Reference

Engine Controls Schematics (LS3) ([1][2]Electrical Diagrams) Engine Controls Schematics (LS7) ([1][2]Electrical Diagrams) Engine Controls Schematics (LS9) ([1][2]Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Fuel System Description (With LS9) (Fuel System Description) Fuel System Description (With LS3 or LS7) (Fuel System Description)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing For Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the FPCM.
2. Connect a DMM set on the volt setting, between the enable control circuit terminal 13 and ground.
3. Ignition ON, command the ECM fuel pump ON with a scan tool. The DMM reading should be between 11.5-12.5 V.

• If less than the specified range, test the enable control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.

4. If all circuits test normal, replace the FPCM.

Repair Instructions

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

* Fuel Pump Flow Control Module Replacement (Service and Repair)
* Engine Control Module Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for FPCM replacement, setup, and programming