2005 Lexus ES 330FACTORY OEM SERVICE PROCEDURE

Inspection Procedure

  1. INSPECT ECM (+B VOLTAGE) 
    1. Turn the ignition switch to ON.
    2. Measure the voltage between the specified terminals of the E6 and E8 ECM connectors.

    Standard: 

    CONNECTOR SPECIFIED CONDITION

    Tester Connection Specified Condition
    +B (E6-1) - E1 (E8-1) 9 to 14V
    +B2 (E6-2) - E1 (E8-1) 9 to 14V

    OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON  PROBLEM SYMPTOMS TABLE  

    Fig 1: Identifying Connectors E8 And E6 Of ECM (+B Voltage)
    G02937903Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: GO TO NEXT STEP 

  2. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) 
    1. Disconnect the E8 ECM connector.
    2. Check the resistance between the wire harness side connectors.

      Standard (Check for open): 

      TERMINALS SPECIFIED CONDITION

      Tester Connection Specified Condition
      E1 (E8-1) - Body ground Below 1 Ω
    3. Reconnect the ECM connector.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: GO TO NEXT STEP 

    Fig 2: Disconnecting E8 ECM Connector
    G02937904Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. INSPECT ECM (IGSW VOLTAGE) 
    1. Turn the ignition switch to ON.
    2. Measure the voltage between the specified terminals of the E6 and E8 ECM connectors.

    Standard: 

    TERMINALS SPECIFIED CONDITION

    Tester Connection Specified Condition
    IGSW (E6-9) - E1 (E8-1) 9 to 14V

    OK: Go to step   6 

    NG: GO TO NEXT STEP 

    Fig 3: Identifying Connector E8 And E6 Of ECM (IGSW Voltage)
    G02937905Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. INSPECT FUSE (IGN FUSE) 
    1. Remove the IG2 fuse from the engine room J/B.
    2. Check for continuity in the IG2 fuse.

      Standard: Continuity 

    3. Reinstall the IG2 fuse.

    NG: CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED FUSE 

    OK: GO TO NEXT STEP 

    Fig 4: Identifying IG2 Fuse
    G02937906Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  5. INSPECT IGNITION OR STARTER SWITCH ASSY 
    1. Disconnect the I14 ignition switch connector.
    2. Check for continuity between the connector terminals shown in the table below.

    Standard: 

    TERMINALS SPECIFIED CONDITION

    Switch Tester Connection Specified Condition
    LOCK All Terminals 10 kΩ or higher
    ACC 2 - 3 Below 1 kΩ
    ON 2 - 3, 2 - 4, 3 - 4, 6 - 7 Below 1 kΩ
    START 1 - 2, 1 - 4, 2 - 4, 6 - 7, 6 - 8, 7 - 8 Below 1 kΩ

    NG: REPLACE IGNITION OR STARTER SWITCH ASSY 

    Fig 5: Identifying I14 Ignition Switch Connector
    G02937907Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: CHECK AND REPAIR HARNESS AND CONNECTOR (BATTERY - IGNITION SWITCH, IGNITION SWITCH - ECM) 

  6. INSPECT ECM (MREL VOLTAGE) 
    1. Turn the ignition switch to ON.
    2. Measure the voltage between the specified terminals of the E6 and E8 ECM connectors.

    Standard: 

    TERMINAL SPECIFIED CONDITION

    Tester Connection Specified Condition
    MREL (E6-8) - E1 (E8-1) 9 to 14V

    NG: REPLACE ECM (See  REPLACEMENT  ) 

    Fig 6: Identifying Terminals E8 And E6 Of ECM (MREL Voltage)
    G02937908Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: GO TO NEXT STEP 

  7. INSPECT FUSE (EFI FUSE) 
    1. Remove the EFI fuse from the engine room J/B.
    2. Measure the resistance in the EFI fuse.

      Standard: Below 1 Ω 

    3. Reinstall the EFI fuse.

    NG: CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED FUSE 

    Fig 7: Identifying EFI Fuse
    G02937909Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  8. INSPECT EFI RELAY 
    1. Remove the EFI relay from the engine room J/B.
    2. Check for continuity in the EFI relay.

    Standard: 

    TERMINAL SPECIFIED CONDITION

    Tester Connection Specified Condition
    3 - 5 10 kΩ or higher
    Below 1 Ω (Apply battery voltage to terminals 1 and 2)
  9. Reinstall the EFI relay.

    NG: REPLACE EFI RELAY 

    Fig 8: Identifying EFI Relay Connector Terminal
    G02937910Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: GO TO NEXT STEP 

  10. CHECK HARNESS AND CONNECTOR (EFI RELAY - ECM, EFI RELAY - BODY GROUND) 
    1. Check the harness and connector between the EFI relay and ECM connector.
      1. Remove the EFI relay from the engine room J/B.
      2. Disconnect the E6 ECM connector.
      3. Check the resistance between the wire harness side connectors.

        Standard (Check for open): 

        TESTER CONNECTION AND TERMINAL SPECIFIED CONDITION

        Tester Connection Specified Condition
        EFI relay (1) - MREL (E6-8) Below 1 Ω

        Standard (Check for short): 

        TESTER CONNECTION AND TERMINAL SPECIFIED CONDITION

        Tester Connection Specified Condition
        EFI relay (1) or MREL (E6-8) - Body ground 10 kΩ or higher
      4. Reinstall the EFI relay.
      5. Reconnect the ECM connector.
    2. Check the harness and the connector between the EFI relay and the body ground.
      1. Remove the EFI relay from the engine room J/B.
      2. Check the resistance between the wire harness side connector and the body ground.

      Standard (Check for open): 

      TESTER CONNECTION AND TERMINAL SPECIFIED CONDITION

      Tester Connection Specified Condition
      EFI relay (2) - Body ground Below 1 Ω
    3. Reinstall the EFI relay.
      Fig 9: Identifying EFI Relay
      G02937911Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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