P1255

DTC P1255 or P064A

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.

DTC Descriptors
DTC P064A
- Fuel Pump Control Module Performance

DTC P1255
- Fuel Pump Control Module Driver Overtemperature

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 two 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 engine is running.

Conditions for Setting the DTC

The FPCM detects an overtemperature fault.

Action Taken When the DTC Sets

DTC P064A and P1255 are A type DTCs.

Conditions for Clearing the DTC

DTC P064A and P1255 are A type DTCs.

Diagnostic Aids

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.

Reference Information
Schematic Reference

Engine Controls Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Fuel System Description (Fuel System Description)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

DTC Type Reference

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

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

Circuit/System Testing

Important: Verify that DTC P0231, P0232 or P023F are not set as current or history before performing this diagnostic. If any of those codes are set as current or history, go to DTC P0231, P0232, or P023F (P0231).


1. Check that the entire undercarriage of the vehicle is clean, especially around the spare tire area where the FPCM is located. Clear all codes from the FPCM and test drive the vehicle. Verify that DTC P1255 or P064A do not set as current.

• If DTC P1255 or P064A reset as current, replace the FPCM.

2. If the DTCs do not set in the FPCM again, the system is okay. Do not replace the FPCM.

Repair Instructions

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

Control Module References (Programming and Relearning) for FPCM replacement, setup, and programming