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 engine is running.

The FPCM detects an over-temperature fault.

P1255 are Type A DTCs.

P1255 are Type A DTCs.

Using the Failure Records data may help locate an intermittent condition. If you cannot duplicate the DTC, the information in the Failure Records can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can help determine how many ignition cycles that the diagnostic test reported a pass and/or a fail.

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

Fuel Pump Flow Control Module Scan Tool Information for scan tool information

1. Verify that DTC P12A7 is not set.

⇒	If the DTC is set, refer to DTC P12A7.

2. Ensure that the entire undercarriage of the vehicle is clean, especially around the area where the FPCM is located. Clear all codes from the FPCM and test drive the vehicle. Verify that DTC P1255 is not set.

⇒	If DTC P1255 resets, replace the FPCM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for FPCM replacement, setup, and programming