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Home >> Lexus >> 2008 >> GS 350 AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - System And Circuit Testing, On-Vehicle Inspection, Removal, Inspection & Installation >> ECM Power Source Circuit >> Inspection Procedure
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Inspection Procedure

  1. INSPECT ECM (+B, +B1 VOLTAGE) 
    1. Turn the engine switch on (IG).
    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Specified Condition
      A6-6 (+B) - E7-7 (E1) 9 to 14 V
      A6-5 (+B1) - E7-7 (E1) 9 to 14 V

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

    Fig 1: Identifying E7 And A6 Connector
    G05803483Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG : Go to next step 

  2. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) 
    1. Disconnect the E7 ECM connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance (Check for open) 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Specified Condition
      E7-7 (E1) - Body ground Below 1 Ω

    NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 2: Identifying E7 ECM Connector
    G05803484Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : Go to next step 

  3. INSPECT ECM (IGSW VOLTAGE) 
    1. Turn the engine switch on (IG).
    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Specified Condition
      A6-17 (IGSW) - E7-7 (E1) 9 to 14 V

    OK :  Go to step  6

    Fig 3: Identifying E7 And A6 ECM Connector
    G05285287Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG : Go to next step 

  4. CHECK FUSE (IGN FUSE) 
    1. Remove the IGN fuse from the cowl side junction block RH.
    2. Measure the resistance of the IGN fuse.

      Standard resistance: 

      Below 1 Ω 

    NG : CHECK FOR SHORT IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE 

    Fig 4: Identifying IGN Fuse From Cowl Side Junction Block RH
    G05285288Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : Go to next step 

  5. INSPECT IG2 RELAY 
    1. Remove the IG2 relay from the engine room No. 2 relay block.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Specified Condition
      3-5 10 kΩ or higher
      3-5 Below 1 Ω (when battery voltage applied to terminals 1 and 2)
      Fig 5: Inspecting IG2 Relay
      G04967794Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG : REPLACE IG2 RELAY 

    OK :  GO TO SMART ACCESS SYSTEM WITH PUSH-BUTTON START

  6. INSPECT ECM (MREL VOLTAGE) 
    1. Turn the engine switch on (IG).
    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Specified Condition
      A6-13 (MREL) - E7-7 (E1) 9 to 14 V

    NG : REPLACE ECM 

    Fig 6: Identifying E7 And A6 ECM Connector
    G05285290Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : Go to next step 

  7. CHECK FUSE (EFI FUSE) 
    1. Remove the EFI fuse from the engine room No.2 junction block.
    2. Measure the resistance of the EFI fuse.

      Standard resistance: 

      Below 1 Ω 

    NG : CHECK FOR SHORT IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE 

    Fig 7: Identifying EFI Fuse From Engine Room No.2 Junction Block
    G05803489Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : Go to next step 

  8. INSPECT INTEGRATION RELAY (EFI MAIN RELAY) 
    1. Remove the integration relay from the engine room No. 2 junction block.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Specified Condition
      2C-1 - 2A-8 10 kΩ or higher
      Below 1 Ω (when battery voltage applied to terminals 2A-6 and 2A-7)

    NG : REPLACE INTEGRATION RELAY 

    Fig 8: Identifying Integration Relay From Engine Room No. 2 Junction Block
    G05285292Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : Go to next step 

  9. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY- ECM, INTEGRATION RELAY - BODY GROUND) 
    1. Check the harness and the connectors between the integration relay and the ECM.
      1. Remove the integration relay from the engine room No. 2 junction block.
      2. Disconnect the A6 ECM connector.
      3. Measure the resistance according to the value(s) in the table below.

        Standard resistance (Check for open) 

        STANDARD RESISTANCE SPECIFICATION

        Tester Connection Specified Condition
        2A-6 - A6-13 (MREL) Below 1 Ω

        Standard resistance (Check for short) 

        STANDARD RESISTANCE SPECIFICATION

        Tester Connection Specified Condition
        2A-6 or A6-13 (MREL) - Body ground 10 kΩ or higher
    2. Check the harness and the connectors between the integration relay and body ground.
      1. Remove the integration relay from the engine room No. 2 junction block.
      2. Measure the resistance according to the value(s) in the table below.
        Fig 9: Identifying Integration Relay And A6 ECM Connector
        G05285293Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

        Standard resistance (Check for open) 

        STANDARD RESISTANCE SPECIFICATION

        Tester Connection Specified condition
        2A-7 - Body ground Below 1 Ω

    NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK : CHECK AND REPAIR HARNESS OR CONNECTOR (TERMINAL +B OF ECM - BATTERY POSITIVE TERMINAL) 

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