Chart A-7A, Fuel System Diagnosis (Fuel Pump Relay Check): Notes

When ignition is turned on, ECM energizes fuel pump relay for 3 seconds, allowing fuel pump operation. When fuel pump relay is de-energized, fuel pump stops operating. If engine is being cranked or is running, fuel pump will continue to operate as long as ECM is receiving ignition reference pulses. If ignition reference pulses are not detected, fuel pump will stop after 3 seconds.

1. Verifies fuel pump operation with ignition on.
2. Checks fuel pump relay switch for power.
3. This checks for faulty ECM or improper fuel pressure.
4. Checks fuel pump circuit.
5. Checks for open in Pink/Black wire.
6. Checks for power at fuel pump relay coil.
7. Checks for a faulty fuel pump or an open in Black wire.
8. Checks for faulty fuel pump relay.
9. Checks for faulty ECM and an open in Pink wire.