The ECM provides ground to one side of the coil in the fuel pump relay to control the fuel pump relay. The other side of the fuel pump relay coil is connected to fuel pump relay, which activates when the ignition switch is ON. The ECM monitors the control circuit between the fuel pump relay and the ECM. When the ignition switch is turned ON, the ECM energizes the fuel pump relay, which sends power to the fuel pump.
If there is Short to ground in fuel pump circuit, ECM sets DTC P0231.
Item
Detecting Condition
Possible Cause
DTC Strategy
Circuit continuity check, low
Poor connection
Short to ground in control circuit
Fuel pump relay
Enable Conditions
-
Threshold Value
Short circuit to Ground
Diagnostic Time
Continuous
MIL ON Condition
DTC only