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Home >> Lexus >> 2012 >> IS F >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostic Codes (P1604-U0101) & Circuit Tests)) >> SFI System >> Circuit Tests >> MIL Circuit >> Procedure
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MIL Circuit: Procedure

  1. CHECK THAT MIL IS ILLUMINATED 
    1. Turn the engine switch on (IG).
    2. Check the illumination of the MIL.

      Result

      Result Proceed to
      MIL remains illuminated (Even after engine switch on (IG) and several seconds have passed, MIL still remains illuminated) A
      MIL remains off (Does not illuminate at all) B
      MIL illuminates for several seconds, but turns off after engine is started C

    B → See step   5 

    C → See step   14 

    A: Go to next step 

  2. CHECK IF MIL TURNS OFF 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG) and turn the Techstream on.
    3. Check if DTCs have been stored. Refer to DTC CHECK / CLEAR . If DTCs are present, write them down.
    4. Clear DTCs. Refer to DTC CHECK / CLEAR .
    5. Check that the MIL turns off.

      OK

      MIL turns off.

    NG → See step   3 

    OK → See step   8 

  3. CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT IN WIRE HARNESS) 
    1. Disconnect the A5 ECM connector.
    2. Turn the engine switch on (IG).
    3. Check that the MIL is not illuminated.

      OK

      MIL is not illuminated.

    4. Reconnect the ECM connector.

    NG → See step   4 

    OK → See step   9 

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

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      J35-12 (EFI) or A5-11 (W) - Body ground Always 10 kΩ or higher
    4. Reconnect the combination meter connector and ECM connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   10 

  5. CHECK THAT ENGINE STARTS 
    1. Start the engine.

      Result

      Result Proceed to
      Engine starts A
      Engine does not start* B

      HINT: 

      *: The Techstream cannot communicate with the ECM.

    B → See step   12 

    A: Go to next step 

  6. CHECK HARNESS AND CONNECTOR (ECM TERMINAL VOLTAGE) 
    1. Disconnect the ECM connector.
    2. Turn the engine switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      A5-11 (W) - Body ground Engine switch on (IG) 11 to 14 V
    4. Reconnect the ECM connector.

    NG → See step   7 

    OK → See step   11 

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

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      J35-12 (EFI) - A5-11 (W) Always Below 1 Ω
    4. Reconnect the combination meter connector and ECM connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   13 

  8. REPAIR CIRCUITS INDICATED BY OUTPUT DTCS. Refer to  DIAGNOSTIC TROUBLE CODE CHART 
  9. REPLACE ECM. Refer to  REMOVAL 
  10. REPAIR OR REPLACE COMBINATION METER. Refer to  REMOVAL 
  11. REPLACE ECM. Refer to  REMOVAL 
  12. GO TO VC OUTPUT CIRCUIT. Refer to  VC Output Circuit  
  13. REPLACE COMBINATION METER ASSEMBLY. Refer to  REMOVAL 
  14. CHECK FOR INTERMITTENT PROBLEMS. Refer to  CHECK FOR INTERMITTENT PROBLEMS 
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