Diagnosis & Repair
WARNING: This page is about a different car, the 2000 Toyota Land Cruiser. However, it is still accessible from the selected car via links, so may be relevant.
- Check fuel pump operation. See FUEL SYSTEMS in SYSTEM & COMPONENT TESTING - V6 & V8 article. If problem exists, go to next step. If problem does not exist, go to step 7.
- Disconnect fuel pump ECU 10-pin harness connector. Turn ignition on. Measure voltage between ground and terminal No. 10 (Black/Yellow wire) at fuel pump ECU harness connector. See Fig 1. If voltage is 9-14 volts, go to next step. If voltage is not 9-14 volts, check for open or short in Black/Yellow wire between EFI main relay and fuel pump ECU. See WIRING DIAGRAMS article.
- With ignition switch in START position, measure voltage between terminals No. 5 (White/Black wire) and No. 8 (Green/White wire) at fuel pump ECU harness connector. If voltage is 3.3-4.3 volts, go to step 5. If voltage is not 3.3-4.3 volts, go to next step.
- Check for open or short in FPC circuit between ECM and fuel pump ECU. Also check fuel pump ECU ground circuit. See WIRING DIAGRAMS article. If problem exists, repair as necessary. If problem does not exist, replace ECM.
- Check fuel pump resistance. See FUEL SYSTEMS in SYSTEM & COMPONENT TESTING - V6 & V8 article. If resistance is not as specified, replace fuel pump. If resistance is as specified, go to next step.
- Check for open or short in wiring between fuel pump and fuel pump ECU. See WIRING DIAGRAMS article. If problem exists, repair wiring as necessary. If problem does not exist, replace fuel pump.
- Check for open or short in Green/Red wire between terminal No. 4 at ECM harness connector E9 and terminal No. 9 at fuel pump ECU harness connector. If problem exists, repair wiring as necessary. If problem does not exist, replace ECM.