P0231

DTC P0231, P0232, or P023F

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 P0231 00
- Fuel Pump Control Circuit Low Voltage

DTC P0232 00
- Fuel Pump Control Circuit High Voltage

DTC P023F 00
- Fuel Pump Control Circuit




Diagnostic Fault Information






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 FSCM detects a fault on the fuel pump voltage circuit that is above or below a predetermined voltage threshold.
* The above condition is present for greater than 12.5 milliseconds.



Action Taken When the DTC Sets

* DTC P0231 and P023F are A type DTCs.
* DTC P0232 is a B type DTC.



Conditions for Clearing the DTC

* DTC P0231 and P023F are A type DTCs.
* DTC P0232 is a B type DTC.



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 (Component Connector End 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

Programming and Relearning (Programming and Relearning)for scan tool information


Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the FPCM. Test for 1.0 ohm or less between terminal 16 and 47.

• If greater than the specified value, test the fuel pump voltage circuit and the fuel pump return ground circuits for an open/high resistance. If those circuits test normal, replace the fuel tank pump module.

2. Ignition OFF, reconnect the harness connector at the FPCM. Disconnect the harness connector at the fuel pump and sender assembly.
3. Within two seconds of the ignition ON, test for 2 volts or greater between the fuel pump module voltage circuit terminal 1 and ground.

• If less than the specified range, test the fuel pump voltage circuit for a short to ground or an open/ high resistance. If the circuit tests normal, replace the FPCM.

4. Ignition OFF, test for 0 volts between the fuel pump module voltage circuit terminal 1 and ground.

• If greater than the specified value, test the fuel pump voltage circuit for a short to voltage. If the circuit tests normal, replace the FPCM.

5. Ignition ON, test for 1.0 ohm or less between the fuel pump low reference circuit terminal 2 and ground.

• If greater the specified value, test the fuel pump low reference circuit for an open/high resistance. If the circuit tests normal, replace the FPCM.

6. If all circuits test normal, replace the fuel tank pump module.



Repair Instructions

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

* Programming and Relearning (Programming and Relearning)for FPCM replacement, setup, and programming
* Fuel Tank Fuel Pump Module Replacement