Diagnostic Instructions
| • | 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. |
DTC Descriptor
DTC P064A 00: Fuel Pump Control Module PerformanceDTC P1255 00: Fuel Pump Control Module Driver Overtemperature
Circuit/System Description
The engine control module (ECM) supplies a high voltage signal to the fuel pump control module (FPCM) when the ECM detects that the ignition is on. The high voltage signal from the ECM to the FPCM remains active for two seconds, unless the engine is in crank or run. While this signal is being received, the FPCM closes the ground switch of the fuel pump and also 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. |
| • | The above condition is present for greater than 12.5 milliseconds. |
Action Taken When the DTC Sets
DTC P064A and P1255 are B type DTCs.
Conditions for Clearing the DTC
DTC P064A and P1255 are B 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
Connector End View Reference
Description and Operation
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References 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 .
- 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 the DTCs do not set in the FPCM again, the system is okay. Do not replace the FPCM.
| ⇒ | If DTC P1255 or P064A reset as current, replace the FPCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for FPCM replacement, setup, and programming
