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.
ECM sets DTC P0230 if the ECM detects that fuel pump relay control line is open or short to ground or battery line.
Item
Detecting Condition
Possible cause
DTC Strategy
? Circuit continuity check
? Short to ground in control circuit(pin 70 to chassis ground)
? Open in control circuit (pin 70)
? Faulty fuel pump relay
? Faulty ECM
Threshold value
? Shorted or disconnected
Enable Conditions
Diagnostic Time
Fail Safe
? None
Service standard
Ignition switch ON : ON 1.5 sec ?OFF
Engine running : ON
This signal waveform shows how MAIN RELAY and FUEL PUMP operate each other.
Point ? is the duration ECM makes FUEL PUMP RELAY ON for 1.5 second after ignition switch ON.
Point ? is MAIN RELAY ON and its voltage should be over 12V.
Point ? is where ECM makes FUEL PUMP ON when it detects starting RPM(50) with CKPS signal.