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Home >> Lexus >> 2008 >> LX 570 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - System Descriptions And Testing, On-Vehicle Inspection, Removal And 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 

    RESULT REFERENCE

    Result 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 Techstream to the DLC3.
    2. Turn the engine switch on (IG) and turn the Techstream on.
    3. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
    4. Check if any DTCs are output. Note down any DTCs.
    5. Clear DTCs (See DTC CHECK/CLEAR ).
    6. Check if the MIL goes off.

    Standard: 

    MIL goes off 

    NG:  Go to step  3

    OK: REPAIR CIRCUITS INDICATED BY OUTPUT DTCS  (See DIAGNOSTIC TROUBLE CODE CHART )

  3. CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT IN WIRE HARNESS) 
    1. Disconnect the A38 ECM connector.
    2. Turn the engine switch on (IG).
    3. Check that the MIL is not illuminated.

      OK: MIL is not illuminated. 

    NG:  Go to step  4

    Fig 1: Identifying Terminals Of A38 ECM Connector
    G05628195Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: REPLACE ECM  (See ECM )

  4. CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM) 
    1. Disconnect the A38 ECM connector.
    2. Disconnect the E77 combination meter connector.
    3. Measure the resistance according to the value(s) in the table below.

    Standard Resistance 

    TESTER CONNECTION SPECIFIED CONDITION CHART

    Tester Connection Condition Specified Condition
    A38-24 (W) or E77-18 (CHK) - Body ground Always 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 2: Identifying Terminals Of E77 Combination Meter Connector
    G05757830Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: REPLACE COMBINATION METER ASSEMBLY  (See REMOVAL )

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

      OK: MIL is illuminated. 

    NG:  Go to step  6

    OK: SYSTEM OK 

  6. CHECK THAT ENGINE STARTS 
    1. Turn the engine switch on (IG).
    2. Start the engine.

      Result 

    RESULT REFERENCE

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

    B: GO TO VC OUTPUT CIRCUIT  (See VC OUTPUT CIRCUIT )

    A: Go to Next Step 

  7. CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM) 
    1. Disconnect the A38 ECM connector.
    2. Disconnect the E77 combination meter connector.
    3. Measure the resistance according to the value(s) in the table below.

    Standard Resistance 

    TESTER CONNECTION SPECIFIED CONDITION CHART

    Tester Connection Condition Specified Condition
    A38-24(W) - E77-18 (CHK) Always Below 1 Ω

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 3: Identifying Terminals Of E77 Combination Meter Connector
    G05757830Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: REPLACE COMBINATION METER ASSEMBLY  (See REMOVAL )

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