Code 42 - Fuel Pump Malfunction
- Use fused jumper wire to apply battery voltage to fuel pump test terminal, taped to harness near in left side of engine compartment. If fuel pump does not run, go to next step. If fuel pump runs, go to step 4).
- Unplug connector from fuel pump. Test Black wire at fuel pump harness connector for continuity to ground. If continuity exists, go to next step. If continuity does not exist, repair Black wire to ground.
- Test for continuity between Yellow wire at fuel pump harness connector and fuel pump test terminal. If continuity exists, go to next step. If continuity does not exist, repair Yellow wire.
- Unplug connector from MFI relay. Turn ignition on. Test for battery voltage at relay harness connector pin No. 3 (Black/White wire). Battery voltage should exist. Hold ignition switch in START position while measuring voltage at harness connector pin No. 7 (Black/Yellow wire). Voltage should not be less than 8 volts. Repair appropriate wire if voltage is not as specified. See appropriate WIRING DIAGRAM in WIRING DIAGRAMS section.
- Turn ignition off. Leave fuel pump disconnected. Unplug 26-pin connector from ECM. Test for continuity between ECM connector terminal No. 6 (White/Red wire) and MFI relay connector terminal No. 9. Test same wire for short to ground and to other wires. See appropriate WIRING DIAGRAM in WIRING DIAGRAMS section. Repair wire as necessary. If White/Red wire is okay, go to next step.
- Test Black wire at MFI relay harness connector for continuity to ground. If continuity does not exist, repair Black wire as necessary. See appropriate WIRING DIAGRAM in WIRING DIAGRAMS section. If continuity exists, go to next step.
- Temporarily substitute known good MFI relay, then retest system. If relay is okay, temporarily substitute known good fuel pump, then retest system. If fuel pump is okay, temporarily substitute known good ECM, then retest system.