Volt

DTC P0231, P0232, or P023F

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 rail pressure.

P0231, P023F

The ignition voltage is between 9-18 V.

P0232

The control enable voltage signal supplied for the ECM to fuel pump control module is inactive for 4 seconds after engine has been shut off.

The fuel pump control module detects a fault on the fuel pump voltage circuit that is less than 11 V or greater than 18 V.

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.

On vehicles equipped with a high pressure mechanical pump on Direct Fuel Injection engines, the vehicle may continue to run even though the pump in the fuel tank is not operating.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Fuel System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Vehicle in Service Mode, command the fuel pump ON and OFF using the scan tool ECM fuel pump output control. The fuel pump should turn ON and OFF.

1. Vehicle OFF, disconnect the harness connector at the G12 fuel pump.
2. Connect a test lamp between the control circuit terminal 1 and ground.
3. Vehicle in Service Mode, command the G12 fuel pump ON and OFF with a scan tool. The test lamp should turn ON and OFF, as commanded.

⇒	If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K27 fuel pump control module.

⇒	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 K27 fuel pump control module.

4. Vehicle OFF, connect a test lamp between the control circuit terminal 1 and the low reference circuit terminal 2.
5. Vehicle in Service Mode, command the G12 fuel pump ON with a scan tool. The test lamp should illuminate.

⇒	If the test lamp does not illuminate, test the low reference circuit terminal 2 for a short-circuit to voltage or an open/high resistance. If the circuit tests normal, replace the K27 fuel pump control module.

6. If all circuits test normal, replace the G12 fuel pump.

Perform the Diagnostic Repair Verification after completing the repair.