Code P020, Open Fuel Pump Circuit: Notes

Fuel pump receives power from circuit No. 120 through either the fuel pump relay or oil pressure switch. PCM energizes fuel pump relay for 2 seconds after key is turned on to provide fuel pressure for starting. After 2 second fuel prime, PCM will not power fuel pump relay until distributor reference pulses are received indicating engine is cranking or running. The oil pressure switch is provided as a backup to fuel pump relay enabling engine to start when fuel pump relay fails.

Normal operation of oil pressure will close normally open oil pressure switch contacts providing a connection between circuits No. 239 and 120. PCM monitors voltage on fuel pump power circuit No. 120 to detect fuel pump voltage supply faults. Code P020 is set when PCM sees fuel pump is not energized (zero volts on feedback circuit) with engine cranking or running. PCM code is designed to detect a fuel pump relay fault (relay not powering fuel pump).