Here are the diagnostic procedures for the fuel pump system.
FUEL PUMP SYSTEM TEST
1. Turn ignition on. With fingers, pinch fuel feed hose at fuel filter. Fuel pressure pulsation should be felt for 5 seconds after ignition is turned on. If pulsation is not felt, go to next step. If pulsation is felt, system is functioning properly.
2. Turn ignition off. Disconnect fuel pump relay. Fuel pump relay is located in relay box next to battery. Turn ignition on. Measure voltage between ground and fuel pump relay harness connector terminals No. 1 (Blue/Black wire) and No. 3 (Blue/Black wire). Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check 15-amp fuse in main fuse box. Check harness continuity between fuse and fuel pump relay. Repair or replace as necessary.
3. Turn ignition off. Disconnect fuel pump harness connector, located under rear seat. Check continuity between ground and fuel pump harness connector Black wire. Check continuity between fuel pump relay harness connector terminal No. 5 (Black/Red wire) and fuel pump harness connector Black/Red wire. Continuity should exist in both checks. If continuity exists in both checks, go to next step. If continuity does not exist, repair appropriate harness or connectors.
4. Ensure ignition is off. Disconnect ECM harness connector. ECM is located under center of instrument panel (connector is on passenger's side). Check continuity between ECM harness connector terminal No. 8 (Black/Yellow wire) and fuel pump relay harness connector terminal No. 2 (Black/Yellow wire). Continuity should exist. If continuity does not exist, check harness between ECM and relay. Repair harness and connectors as necessary. If continuity exists, check fuel pump relay. If relay is okay, check fuel pump.
Monday, December 20th, 2010 AT 5:15 PM