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Diagnosis & Repair

WARNING: This page is about a different car, the 2002 Toyota Land Cruiser. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Before performing this test procedure ensure reset switch on fuel pump switch is in the ON position. Fuel pump switch is located on driver's side of instrument panel. See Fig 1. Fuel pump switch may also be referred to as fuel pump inertia switch or fuel pump control switch.
  1. Check fuel pump operation. See FUEL PUMP OPERATION under FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article. If fuel pump does not operate, go to next step. If fuel pump operates, go to step  8.
  2. Remove driver's side quarter trim panel for access to fuel pump ECU. Fuel pump ECU is located behind inner panel, just behind driver's side rear wheelwell. See Fig 2.
  3. Disconnect 10-pin electrical connector at fuel pump ECU. Turn ignition on. Using voltmeter, check voltage between body ground and terminal No. 10 (Black/Yellow wire) at fuel pump ECU electrical connector. See Fig 3. Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, check for open and short in Black/Yellow wire and electrical connectors between EFI main relay and fuel pump ECU. See WIRING DIAGRAMS article. EFI main relay may also be referred to as EFI relay. EFI main relay is located in fuse/relay box at driver's side front corner of engine compartment. Repair wiring harness or electrical connector as necessary.
  4. Using voltmeter, check voltage between terminals No. 5 (White/Black wire) and No. 8 (Green/White wire) at fuel pump ECU electrical connector with ignition switch in START position. See Fig 3. Voltage should be 3.3-4.3 volts. If voltage is not within specification, go to next step. If voltage is within specification, go to step  6.
  5. Check for open or short in Green/White and Green/Red wires and electrical connectors between ECM, fuel pump switch and terminal No. 8 at fuel pump ECU. See WIRING DIAGRAMS article. Also, check for open in White/Black wire and electrical connectors between ground connection and terminal No. 5 at fuel pump ECU. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, replace ECM. If wiring harness or electrical connector are defective, repair as necessary.
  6. Check fuel pump resistance and operation. See FUEL DELIVERY under FUEL SYSTEMS in SYSTEM & COMPONENT TESTING - V6 & V8 article. If fuel pump resistance is within specification and fuel pump operates, go to next step. If fuel pump resistance is not within specification or fuel pump does not operate, replace fuel pump. See FUEL PUMP under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article.
  7. Check for open and short in wiring harness and electrical connectors between fuel pump ECU and fuel pump. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, replace fuel pump ECU. If wiring harness or electrical connector are defective, repair as necessary.
  8. Check for open and short in Green/Red wire and electrical connectors between terminal No. 4 at ECM electrical connector E9 and terminal No. 9 at fuel pump ECU. See WIRING DIAGRAMS article. ECM is located behind glove box. See Figure. For ECM electrical connector terminal identification, see Figure. Fuel pump ECU is located behind inner panel, just behind driver's side rear wheelwell. See Fig 2. For fuel pump electrical connector terminal identification, see Fig 3. If wiring harness and electrical connectors are okay, replace ECM. If wiring harness or electrical connector are defective, repair as necessary.
    Fig 1: Locating Fuel Pump Switch & Identifying Reset Switch Positions
    G98J01612Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    Fig 2: Locating Fuel Pump Electronic Control Unit
    G98B01613Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    Fig 3: Identifying Fuel Pump ECU Electrical Connector Terminals
    G98I10205Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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