Code P020, Open Fuel Pump Circuit: Action
PCM turns on SERVICE VEHICLE SOON light.
NOTE:
Test numbers refer to numbers on diagnostic chart.
- Checks for engine to start with fuel pump powered through fuel pump relay. If engine does not start, proceed to CODE P020 (2 OF 3).
- A reading of zero volts with engine running indicates an open from fuel pump power circuit to PCM. Fuel pump relay is not at fault.
- Checks for proper control of fuel pump relay by PCM.
- Checks for open from fuel pump fuse to fuel pump relay terminal No. 5 circuit.
- Checks for open in fuel pump relay terminal No. 2 to ground.
- Checks continuity of complete fuel pump circuit from fuse A1 through the fuel pump windings to ground. When voltmeter is used to jumper the contact cavities of relay connector, voltmeter should read greater than 10 volts if circuit is okay. If circuit is okay, fuel pump relay is faulty.
- If relay or relay drive circuits are grounded, PCM may be damaged by excessive current draw if battery voltage is greater than 16 volts. Repair fault and check for proper operation.
- Fault is most likely at PCM connector or PCM. Check PCM terminals before replacing PCM.
- Check fuel pump circuit. See appropriate wiring diagram in WIRING DIAGRAMS section.
- With ignition on, voltmeter should read greater than 10 volts for 2 seconds as relay powers up the fuel pump.
- If a short is present, check circuit No. 120, fuel pump or PCM. Normal circuit resistance is 3-4 ohms.
- If voltmeter is steady at greater than 10 volts, then the non-switched portion of fuel pump circuit is shorted.
- Checks for PCM shorting circuit No. 120 to ground.
- Checks for short inside fuel tank.
- Check fuel pump and sender harness connector for short circuit.
- Checks circuit No. 120 for short to ground.
- Checks for grounded fuel pump prime/test connector, relay connector and oil pressure switch. Check wiring harness for short to ground.