Diagnostic Aids

An intermittent malfunction may be caused by a poor connection, rubbed through wire insulation or a wire broken inside insulation. Check for an open or loose or disconnected terminals.

1. Remove fuel filler cap. Have an assistant cycle ignition ON and OFF. Listen for fuel pump operation at fuel filler. If fuel pump operates for approximately 2 seconds, go to next step. If fuel pump does not operate, go to step 3).
2. Disconnect fuel pump relay (located in engine compartment relay box). See Figure. Connect test light between battery voltage and fuel pump relay connector terminal No. 2 (Pink/White wire). Crank engine. If test light illuminates while engine is cranking, go to TEST A1-7B  under CIRCUIT TESTS. If test light does not illuminate, replace PCM. Ensure system is operating properly.
3. Disconnect fuel pump relay. Turn ignition on. Connect a test light between ground and fuel pump relay connector terminal No. 4 (White/Blue wire). If test light illuminates, go to next step. If test light does not illuminate, check for an open or short in White/Blue wire between main relay and fuel pump relay. Repair as necessary. Ensure system is operating properly.
4. Turn ignition off. Connect a fused jumper wire between fuel pump relay connector terminal No. 3 (Pink wire) and terminal No. 4 (White/Blue wire). Cycle ignition on and off. Check for fuel pump operation. If fuel pump operates, go to step 7). If fuel pump does not operate, go to next step.
5. Ensure fused jumper wire is still connected. Using a test light connected to ground, backprobe fuel pump harness connector terminal No. 2 (Pink wire). If test light illuminates, go to next step. If test light does not illuminate, check for an open in Pink wire between fuel pump and fuel pump relay. Repair as necessary. Ensure system is operating properly.
6. Turn ignition off. Disconnect fused jumper wire. Disconnect fuel pump connector. Using a test light, probe between fuel pump connector terminal No. 1 (Black wire) and battery voltage. If test light illuminates, replace fuel pump. If test light does not illuminate, check for an open in Black wire or a poor ground connection. Repair as necessary. Ensure system is operating properly.
7. Turn ignition off. Disconnect fused jumper wire. Turn ignition on. Using a test light, probe between fuel pump relay connector terminal No. 1 (Black/White wire) and ground. If test light illuminates, go to next step. If test light does not illuminate, check for an open or short in Black/White wire. Repair as necessary. Ensure system is operating properly.
8. Using a test light, probe between fuel pump relay connector terminal No. 2 (Pink/White wire) and battery voltage. Crank engine. If test light does not illuminate while cranking engine, go to next step. If test light illuminates while engine is cranking, replace fuel pump relay.
9. Using a test light, backprobe between PCM 26-pin connector terminal No. 21 (Pink/White wire) and battery voltage. Crank engine. If test light illuminates while cranking engine, check for an open in Pink/White wire between PCM and fuel pump relay. Repair as necessary. If test light does not illuminate, replace PCM. Ensure system is operating properly.