The powertrain control module (PCM) controls the fuel pump motor by supplying ignition voltage to the fuel pump relay coil. The fuel pump runs continuously whenever the engine is running or runs for 2 seconds if the ignition is turned ON and the engine is not cranked. The PCM controls an internal driver which supplies the fuel pump relay coil direct ignition voltage whenever the fuel pump relay is commanded ON. The relay coil circuit is monitored for low and high voltage faults. DTC P0232 sets when the fuel pump relay is being commanded OFF and the feedback voltage at the PCM is high.
DTC Parameters
DTC P0232 will set if fuel pump relay feedback voltage is greater than 2.5 volts with fuel pump relay commanded OFF when:
| • | The condition exists for longer than 0.5 seconds. |
| • | The ignition is ON. |
DTC P0232 diagnostic runs continuously with ignition ON and fuel pump relay commanded OFF.
DTC P0232 is a type D DTC.
Diagnostic Aids
To locate an intermittent problem, use scan tool to monitor FUEL PUMP REL. - OPEN or FUEL PUMP REL. - HIGH VOLT test with ignition ON, engine OFF. When a fault (open or short to voltage) exists, the scan tool will display TEST FAIL for both tests.
The tests will fail only when the device is being commanded OFF and the voltage at the PCM is high. The tests update every 100 ms whenever the ignition is turned ON and the device is being commanded OFF via the scan tool or PCM.
The PCM supplies voltage on circuit 465 when the fuel pump relay is commanded off. This voltage normally will not light a test light.
The fuel pump relay coil resistance is 75-105 ohms.
