• | 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 |
---|---|---|---|---|
Fuel Pump High Control | P0231 | P023F | P0232 | P023F, P2635 |
Fuel Pump Low Control | -- | P023F | -- | P023F, P2635 |
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 voltage is between 9-18 volts
The control enable voltage signal supplied for the ECM to FPCM is inactive for 4 seconds after engine has been shut off.
The FPCM detects a fault on the fuel pump voltage circuit that is above or below a predetermined voltage threshold.
DTCs P0231, P0232, and P023F are Type A DTCs.
DTCs P0231, P0232, and P023F 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.
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
Ignition ON, command the fuel pump ON and OFF using the scan tool ECM fuel pump output control. The fuel pump should turn ON and OFF.
⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the FPCM. |
⇒ | 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 FPCM. |
⇒ | If the test lamp does not illuminate, test the control circuit terminal A for a short to voltage or an open/high resistance. If the circuit tests normal, replace the FPCM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for FPCM replacement, setup, and programming |