Diagnosis & Repair

Turn ignition on. Using jumper wire, connect DLC1 terminals +B and FP. See Figure. Check if fuel pressure can be felt in hose to fuel filter. If pressure is felt, go to next step. If pressure cannot be felt, go to step 3).
Check for open or short in +B and FP circuits between DLC1 and fuel pump ECU. Fuel pump ECU is located back of left rear wheelwell, behind trim panel. See appropriate wiring diagram in WIRING DIAGRAMS article. Repaire as necessary. If circuits are okay, go to step 5).
Ensure ignition is on. Using DVOM, measure voltage between ground and DLC1 terminal +B. If voltage is 9-14 volts, go to next step. If voltage is not 9-14 volts, inspect ECM power supply circuit and +B circuit between DLC1 connector and main relay. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair as necessary.
Inspect FP circuit for open or short between DLC1 connector, fuel pump and ground. Repair as necessary. If circuit is okay, replace fuel pump.
Access fuel pump ECU. Fuel pump ECU is located back of left rear wheelwell, behind trim panel. Disconnect fuel pump ECU connector. Check voltage between terminals "E" and FPC at ECU wiring harness connector. See Fig 1. Turn ignition switch to START position. If voltage is 4.5-5.5 volts, replace fuel pump ECU. If voltage is not 4.5-5.5 volts, go to next step.
Inspect FPC circuit between ECM and fuel pump ECU for open. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair as necessary. If circuit is okay, inspect "E" circuit between fuel pump ECU and ground. Repair as necessary. If both circuits are okay, go to next step.
Inspect DI circuit between ECM and fuel pump ECU for open or short. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair as necessary. If circuit is okay, replace ECM and retest.

Fig 1: Fuel Pump ECU Harness Connector Terminal ID