Fuel Pump Circuit Test
- When ignition switch is first turned on with engine off, fuel pump should operate for 3 seconds. If fuel pump operates, fuel pump and main relay circuits are functioning properly. If fuel pump does not operate, disconnect fuel pump relay connector. Using jumper wire, connect Pink/Black and Blue/Black wires of fuel pump relay harness. Relay is located under far left side of dash, left of ECM. If fuel pump operates, go to next step. If fuel pump does not operate, go to step 5).
- If fuel pump operates with jumper wire installed, check for power at Black/Red and Black/White wire terminals of EFI main relay with ignition switch in the ON position. If power is NOT present, check for blown 15-amp fuse(s) in fuse box (fuses No. 8 and 14). If fuses are okay, check wiring between ignition switch and main relay.
- If power is present at Black/Red and Black/White wire terminals, Turn ignition off. Connect test light to battery voltage. Probe Pink wire of fuel pump relay with test light. Turn ignition switch to ON position. Test light should illuminate for 3 seconds after ignition is turned on. If test light does not illuminate, go to step 4). If test light illuminates for 3 seconds, test fuel pump relay. See FUEL PUMP RELAY under RELAYS .
- If test light does not illuminate for 3 seconds, check for open in Pink wire between ECM and fuel pump relay harness connector. If wire is okay, check for poor connection of Pink wire at ECM, or faulty ECM. See appropriate WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section.
- If fuel pump did not operate in step 1), disconnect main relay connector. Using a jumper wire, connect Black/Red and Blue/Black wires of main relay harness connector together. If power is now available at Blue/Black wire of fuel pump relay harness, test main relay. If power is not available at Blue/Black wire of fuel pump relay harness, check for blown 15-amp fuse (No. 14) in fuse box. If fuse is okay, repair open in Black/Red wire between fuse box and main relay.