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DTC U0242: Lost Communication With Headlamp Control Module "B" [08/2019 - ]: Procedure

  1. CONFIRM MODEL 
    1. Choose the model to be inspected.

      Result

      Result Proceed to
      for Multiple Beam Headlight A
      for Single Beam Headlight B

    Result: 

    B 

    See step  7

    Result: 

    A 

    See step  2

  2. CHECK FOR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / AFS / Trouble Codes.
    5. Check for DTCs.

      Body Electrical > AFS > Trouble Codes 

      OK

      DTC U0242 is not output.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2019 - 07/2020]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [07/2020 - ] 

    Result: 

    NG 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (NO. 1 HEADLIGHT ECU SUB-ASSEMBLY LH - NO. 1 HEADLIGHT ECU SUB-ASSEMBLY RH) 
    1. Disconnect the A49 No. 1 headlight ECU sub-assembly LH connector.
    2. Disconnect the A50 No. 1 headlight ECU sub-assembly RH connector.
    3. Measure the resistance according to the value (s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A49-22 (LCH) - A50-22 (LCH) Always Below 1 Ω
      A49-21 (LCL) - A50-21 (LCL) Always Below 1 Ω
      A49-22 (LCH) or A50-22 (LCH) - Body ground Always 10 kΩ or higher
      A49-21 (LCL) or A50-21 (LCL) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  4

  4. REPLACE NO. 1 HEADLIGHT ECU SUB-ASSEMBLY RH 
    1. Replace the No. 1 headlight ECU sub-assembly RH with a new one.

      Refer to REMOVAL [08/2019 - ]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  5

  5. CLEAR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / AFS / Trouble Codes.
    5. Clear the DTCs.

      Body Electrical > AFS > Clear DTCs 

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  6

  6. CHECK FOR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / AFS / Trouble Codes.
    5. Check for DTCs.

      Body Electrical > AFS > Trouble Codes 

      OK

      DTC U0242 is not output.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    END (NO. 1 HEADLIGHT ECU SUB-ASSEMBLY RH WAS DEFECTIVE) 

    Result: 

    NG 

    REPLACE NO. 1 HEADLIGHT ECU SUB-ASSEMBLY LH. Refer to  REMOVAL [08/2019 - ] 

  7. CHECK FOR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / HL AutoLeveling / Trouble Codes.
    5. Check for DTCs.

      Body Electrical > HL AutoLeveling > Trouble Codes 

      OK

      DTC U0242 is not output.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2019 - 07/2020]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [07/2020 - ] 

    Result: 

    NG 

    See step  8

  8. CHECK HARNESS AND CONNECTOR (NO. 1 HEADLIGHT ECU SUB-ASSEMBLY LH - NO. 1 HEADLIGHT ECU SUB-ASSEMBLY RH) 
    1. Disconnect the A49 No. 1 headlight ECU sub-assembly LH connector.
    2. Disconnect the A50 No. 1 headlight ECU sub-assembly RH connector.
    3. Measure the resistance according to the value (s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A49-20 (LINL) - A50-20 (LINL) Always Below 1 Ω
      A49-20 (LINL) or A50-20 (LINL) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  9

  9. REPLACE NO. 1 HEADLIGHT ECU SUB-ASSEMBLY RH 
    1. Replace the No. 1 headlight ECU sub-assembly RH with a new one.

      Refer to REMOVAL [08/2019 - ]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  10

  10. CLEAR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / HL AutoLeveling / Trouble Codes.
    5. Clear the DTCs.

      Body Electrical > HL AutoLeveling > Clear DTCs 

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  11

  11. CHECK FOR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / HL AutoLeveling / Trouble Codes.
    5. Check for DTCs.

      Body Electrical > HL AutoLeveling > Trouble Codes 

      OK

      DTC U0242 is not output.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    END (NO. 1 HEADLIGHT ECU SUB-ASSEMBLY RH WAS DEFECTIVE) 

    Result: 

    NG 

    REPLACE NO. 1 HEADLIGHT ECU SUB-ASSEMBLY LH. Refer to  REMOVAL [08/2019 - ] 

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