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Home >> Lexus >> 2007 >> GS 450h >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Component And System Testing, On-Vehicle Inspection, Removal, Inspection & Installation >> MIL Circuit >> Inspection Procedure
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Inspection Procedure

  1. CHECK THAT MIL IS ILLUMINATED 
    1. Perform troubleshooting in accordance with the table below.
      RESULT CHART

      Condition Proceed to
      MIL remains ON A
      MIL does not illuminate B

    B:  GO TO step  5

    A: GO TO Next Step 

  2. CHECK WHETHER MIL TURNS OFF 
    1. Connect the intelligent tester to the DLC3.
    2. Turn the power switch ON (IG) and turn the tester ON.
    3. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODE.
    4. Check if any DTCs have been stored. Note down any DTCs.
    5. Clear DTCs (see DTC CHECK/CLEAR ).
    6. Check if the MIL goes off.

      OK: 

      MIL should go off. 

    OK: REPAIR CIRCUIT INDICATED BY OUTPUT DTC 

    NG: GO TO Next Step 

  3. CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT IN WIRE HARNESS) 
    1. Disconnect the A53 ECM connector.
    2. Turn the power switch ON (IG).
    3. Check that the MIL is not illuminated.

      OK: 

      MIL is not illuminated. 

    4. Reconnect the ECM connector.
      Fig 1: Identifying A53 ECM Connector Terminals
      G05302516Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: REPLACE ECM 

    NG: GO TO Next Step 

  4. CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM) 
    1. Disconnect the K31 combination meter connector.
    2. Disconnect the A53 ECM connector.
    3. Measure the resistance.

      Standard resistance (Check for short) 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      W (A53-24) or EFI (K31-8) - Body ground 10 kΩ or higher
    4. Reconnect the combination meter connector.
    5. Reconnect the ECM connector.
      Fig 2: Identifying K31 Combination Meter Connector Terminals
      G05302517Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: REPAIR OR REPLACE COMBINATION METER ASSEMBLY 

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

  5. CHECK THAT MIL IS ILLUMINATED 
    1. Check if the MIL is illuminated when the power switch is turned ON (IG).

      OK: 

      MIL should be illuminated. 

    OK: SYSTEM OK 

    NG: GO TO Next Step 

  6. CHECK THAT ENGINE STARTS 
    1. Turn the power switch ON (IG).
    2. Start the engine.
      RESULT CHART

      Result Proceed to
      Engine starts A
      Engine does not start* B
      HINT:
      *: The intelligent tester cannot communicate with the ECM.

    B:  GO TO VC OUTPUT CIRCUIT 

    A: GO TO Next Step 

  7. INSPECT COMBINATION METER ASSEMBLY (MIL CIRCUIT) 
    1. Check the MIL circuit (see SYSTEM DIAGRAM ).

    NG: REPAIR OR REPLACE COMBINATION METER ASSEMBLY 

    OK: CHECK AND REPLACE HARNESS OR CONNECTOR (COMBINATION METER - ECM) 

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