Volt

DTC P025A

The engine control module (ECM) supplies voltage to the fuel pump control module when the ECM detects that the ignition is on. The voltage from the ECM to the fuel pump control module remains active for 2 seconds, unless the engine is in crank or run. While this voltage is being received, the fuel pump control module supplies a varying voltage to the fuel tank pump module in order to maintain the desired fuel rail pressure.

The engine is running.

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

DTC P025A is a Type A DTC.

DTC P025A is a Type A DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Fuel System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Vehicle OFF, disconnect the harness connector at the K27 fuel pump control module.
2. Vehicle OFF, connect a test lamp between the control circuit terminal 20 and ground.
3. Vehicle in Service Mode, command the ECM fuel pump enable command ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒	If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

⇒	If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.

4. If all circuits test normal, replace the K27 fuel pump control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for ECM or fuel pump control module replacement, programming and setup