P0231

Diagnostic Chart:

Fuel Pump Relay Control Circuit Low Voltage:

The fuel pump relay is located in the Left Instrument Panel Fuse Block (LIPFB). The ECM controls the fuel pump motor by supplying a ground to the fuel pump relay. 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 ECM controls an internal driver that supplies a ground to the fuel pump relay coil whenever the fuel pump relay is commanded On. The relay coil circuit is monitored for low and high voltage and open circuit faults. DTC P0231 will set if the ECM detects a feedback voltage below a calibrated value in the fuel pump relay control circuit when the relay is commanded Off.

DTC PARAMETERS
DTC P0231 will set if fuel pump relay voltage is below 2.6 volts when fuel pump relay is being commanded Off when:
^ Condition exists for longer than 0.5 seconds
^ Battery is between 7.5 and 15.0 volts
^ Engine is cranking/running

P0231 is a (type D) DTC

DIAGNOSTIC AIDS
Inspect harness for chaffed wires that may cause a short to ground condition.