P1255

DTC P1255 or P064A

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 Descriptors

DTC P064A
- Fuel Pump Control Module Performance

DTC P1255
- Fuel Pump Control Module Driver Over-temperature

Circuit/System Description

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 pressure.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

The fuel pump control module detects an over-temperature fault.

Action Taken When the DTC Sets

DTCs P064A and P1255 are Type A DTCs.

Conditions for Clearing the DTC

DTCs P064A and P1255 are Type A 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 [1][2]Electrical Diagrams

Connector End View Reference

Component Connector End Views Fuel Pump and Level Sensor Assembly

Description and Operation

Fuel System Description 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 Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON.

2. Verify DTC P0231, P0232 or P023F is not set.

• If any of the DTCs are set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.

• If none of the DTCs are set

3. Verify that the area where the K27 fuel pump control module is located is free of debris, clutter, or any insulating material that would cause the K27 fuel pump control module to overheat.

• If any debris, clutter, or other material is found

1. Clear the area where the K27 fuel pump control module is located.

2. Clear the DTC and test drive the vehicle.

3. Verify DTC P1255 or P064A is not set.

• If DTC P1255 or P064A is set, replace the K27 fuel pump control module.

• If DTC P1255 or P064A is not set

4. All OK.

• If no debris, clutter, or other material is found

4. Clear the DTC and test drive the vehicle.

5. Verify DTC P1255 or P064A is not set.

• If DTC P1255 or P064A is set
Replace the K27 fuel pump control module.

• If DTC P1255 or P064A is not set.

6. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

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