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Home >> Lexus >> 2017 >> RX 350 Base, AWD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Exterior Lights >> Lighting System (W/ Automatic Headlight Beam Level Control System) - Diagnostic Codes >> LIGHTING SYSTEM (w/ Automatic Headlight Beam Level Control System) >> DTC B242E: Open in IG Circuit [09/2015 - 08/2019] >> Procedure
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DTC B242E: Open in IG Circuit [09/2015 - 08/2019]: Procedure

  1. CLEAR DTC 
    1. for Single Beam Headlight without AFS (Adaptive Front-lighting System):
      1. Clear the DTCs.

        Refer to DTC CHECK / CLEAR [09/2015 - 08/2019]

        Body Electrical > HL Auto Leveling > Clear DTCs 

    2. for Triple Beam Headlight, for Single Beam Headlight with AFS (Adaptive Front-lighting System):
      1. Clear the DTCs.

        Refer to DTC CHECK / CLEAR [09/2015 - 08/2019]

        Body Electrical > AFS > Clear DTCs 

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  2

  2. CHECK FOR DTC 
    1. Turn the engine switch on (IG).
    2. for Single Beam Headlight without AFS (Adaptive Front-lighting System):
      1. Check for DTCs.

        Refer to DTC CHECK / CLEAR [09/2015 - 08/2019]

        Body Electrical > HL Auto Leveling > Trouble Codes 

        OK

        DTC B242E is not output.

    3. for Triple Beam Headlight, for Single Beam Headlight with AFS (Adaptive Front-lighting System):
      1. Check for DTCs.

        Refer to DTC CHECK / CLEAR [09/2015 - 08/2019]

        Body Electrical > AFS > Trouble Codes 

        OK

        DTC B242E is not output.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [09/2015 - 08/2016]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2016 - 12/2017]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2017 - 08/2019] 

    Result: 

    NG 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY RH - POWER SOURCE AND BODY GROUND) 
    1. Disconnect the A49 headlight ECU sub-assembly LH connector.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A49-4 (IG) - Body ground Engine switch off Below 1 V
      A49-4 (IG) - Body ground Engine switch on (IG) 11 to 14 V
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A49-12 (GND) - Body ground Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH. Refer to  REMOVAL [09/2015 - 08/2016]  , or refer to  REMOVAL [08/2016 - 08/2019] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR