• | 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. |
Circuit | Short to Ground | Open or High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
FPCM Control | P025A | P025A | P025A | -- |
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.
The ignition is ON.
The GMLAN serial data message from the ECM to the FPCM does not agree with the state of the control enable voltage signal supplied from the ECM to the FPCM for more than 2 seconds.
DTC P025A is an A type DTC.
DTC P025A is an A type DTC.
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the 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 ECM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for ECM or FPCM replacement, setup, and programming