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Home >> Lexus >> 2005 >> GS 300 >> Repair and Diagnosis >> Engine Performance >> System >> Engine (2JZ-GE) - Diagnostics >> Circuit Inspection >> Fuel Pump Control Circuit >> Inspection Procedure
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Inspection Procedure

  1. Connect hand-held tester, and check operation of fuel pump (See  FUEL PUMP  ). 
    1. OK: Go to step   7 . 
    2. NG: Go to next step. 
  2. Check voltage of fuel pump ECU power source. 

    PREPARATION: 

    1. Remove the luggage compartment trim cover (See FUEL PUMP ECU ).
    2. Disconnect the fuel pump ECU connector.
    3. Turn the ignition switch ON.

    CHECK: 

    Measure the voltage between terminal 10 of the fuel pump ECU connector and body ground.

    Fig 1: Measuring Voltage Between Terminal 10 Of Fuel Pump ECU Connector And Body Ground
    G02941409Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: 

    Voltage: 9 to 14 V 

    1. NG: Check for open and short in harness and connector between EFI main relay (Marking: EFI) and fuel pump ECU (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ). 
    2. OK: Go to next step. 
  3. Check voltage between terminals 5 and 8 of fuel pump ECU connector. 

    PREPARATION: 

    1. Remove the luggage compartment trim cover (See FUEL PUMP ECU ).
    2. Disconnect the fuel pump ECU connector.

    CHECK: 

    Measure the voltage between terminals 5 and 8 of the fuel pump ECU connector when the ignition switch is turned to the START position.

    Fig 2: Measuring Voltage Between Terminals 5 And 8 Of Fuel Pump ECU Connector
    G02941410Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: 

    Voltage: 3.3 to 4.3 V 

    1. OK: Go to step   5 . 
    2. NG: Go to next step. 
  4. Check for open and short in harness and connector between terminal FPC of ECM and terminal 8 of fuel pump ECU, and terminal 5 of fuel pump ECU and I body ground (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ). 
    1. NG: Repair or replace harness or connector. 
    2. OK: Replace ECM (See  ENGINE CONTROL MODULE (ECM)  ). 
  5. Check fuel pump (See  FUEL PUMP  ). 
    1. NG: Repair or replace fuel pump. 
    2. OK: Go to next step. 
  6. Check for open and short in harness and connector between terminal 7 of fuel pump ECU and fuel pump and terminal 6 of fuel pump ECU and fuel pump (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ). 
    1. NG: Repair or replace harness or connector. 
    2. OK: Replace fuel pump ECU. 
  7. Check for open and short in harness and connector between terminal DI of ECM and terminal 9 of fuel pump ECU (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ). 
    1. NG: Repair or replace harness or connector. 
    2. OK: Replace ECM (See  ENGINE CONTROL MODULE (ECM)  ). 
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