LIGHTING SYSTEM, Diagnostic DTC:U0242

DTC Code DTC Name
U0242 Lost Communication With Headlamp Control Module "B"

DESCRIPTION

The headlight ECU sub-assembly LH stores this DTC when the headlight ECU sub-assembly RH detects an internal malfunction or if a communication malfunction occurs between headlight ECU sub-assembly LH and headlight ECU sub-assembly RH for 10 seconds or more.

DTC No. Detection Item DTC Detection Condition Trouble Area Note
U0242 Lost Communication With Headlamp Control Module "B"

Either of the following conditions is met:


  • Headlight ECU sub-assembly RH internal malfunction

  • Communication malfunction occurs between headlight ECU sub-assembly LH and headlight ECU sub-assembly RH for 10 seconds or more

  • Headlight ECU sub-assembly LH

  • Headlight ECU sub-assembly RH

  • Harness or connector

 -

WIRING DIAGRAM


  1. for Single Beam Headlight

    B005P0SE04
    *1 LINL
    *2 Headlight ECU Sub-assembly LH
    *3 Headlight ECU Sub-assembly RH
    *4 LIN Communication Line

  2. for Triple Beam Headlight with Adaptive High Beam System

    B005NV5E04

  3. for Triple Beam Headlight without Adaptive High Beam System

    B005LM9E03

CAUTION / NOTICE / HINT

Note

If the headlight ECU sub-assembly LH has been replaced, it is necessary to synchronize the vehicle information and initialize the headlight ECU sub-assembly LH.

Click here

PROCEDURE


  1. CONFIRM MODEL


    1. Choose the model to be inspected.

      Result
      Result Proceed to
      for Single Beam Headlight A
      for Triple Beam Headlight with Adaptive High Beam System B
      for Triple Beam Headlight without Adaptive High Beam System C

    B

    CLEAR DTC Click here

    C

    CLEAR DTC Click here

    A

  2. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Body Electrical > HL AutoLeveling > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  3. CHECK FOR DTC


    1. Turn the engine switch on (IG).

    2. Check for DTCs.

      Click here


      Body Electrical > HL AutoLeveling > Trouble Codes
      OK
      DTC U0242 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  4. CHECK HARNESS AND CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY LH - HEADLIGHT SUB-ASSEMBLY RH)


    1. Disconnect the A49 headlight ECU sub-assembly LH connector.

    2. Disconnect the A50 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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH


    1. Replace the headlight ECU sub-assembly RH with a new or known good one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  6. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Body Electrical > HL AutoLeveling > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  7. CHECK FOR DTC


    1. Turn the engine switch on (IG).

    2. Check for DTCs.

      Click here


      Body Electrical > HL AutoLeveling > Trouble Codes
      OK
      DTC U0242 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (HEADLIGHT ECU SUB-ASSEMBLY RH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH Click here

  8. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Body Electrical > AFS > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  9. CHECK FOR DTC


    1. Turn the engine switch on (IG).

    2. Check for DTCs.

      Click here


      Body Electrical > AFS > Trouble Codes
      OK
      DTC U0242 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  10. CHECK FOR DTC


    1. Turn the engine switch on (IG).

    2. Check for DTCs.

      Click here


      Body Electrical > Pre-Crash 2 > Trouble Codes
      OK
      DTC U1002 is not output.
      Result
      Proceed to
      OK
      NG

    NG

    GO TO DTC U1002 Click here

    OK

  11. CHECK HARNESS AND CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY RH - NO. 1 CAN JUNCTION CONNECTOR)


    1. Turn the engine switch off.

    2. Disconnect the cable from the negative (-) battery terminal.

    3. Disconnect the A50 headlight ECU sub-assembly RH connector.

    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A50-21 (LCL) - A50-22 (LCH) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  12. CHECK HARNESS AND CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY LH - NO. 1 CAN JUNCTION CONNECTOR)


    1. Disconnect the A49 headlight ECU sub-assembly LH connector.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A49-21 (LCL) - A49-22 (LCH) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  13. REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH


    1. Replace the headlight ECU sub-assembly RH with a new or known good one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  14. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Body Electrical > AFS > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  15. CHECK FOR DTC


    1. Turn the engine switch on (IG).

    2. Check for DTCs.

      Click here


      Body Electrical > AFS > Trouble Codes
      OK
      DTC U0242 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (HEADLIGHT ECU SUB-ASSEMBLY RH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH Click here

  16. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Body Electrical > AFS > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  17. CHECK FOR DTC


    1. Turn the engine switch on (IG).

    2. Check for DTCs.

      Click here


      Body Electrical > AFS > Trouble Codes
      OK
      DTC U0242 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  18. CHECK CAN BUS LINE (MALFUNCTION CONFIRMATION)


    1. Turn the engine switch off.

    2. Disconnect the cable from the negative (-) battery terminal.

    3. Disconnect the A49 headlight ECU sub-assembly LH connector.

    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      A49-21 (LCL) - A49-22 (LCH) Cable disconnected from negative (-) battery terminal 108 to 132 Ω

      132 Ω or more:

      Open circuit in main bus lines

      Below 108 Ω:

      Short circuit between bus lines
      A49-21 (LCL) - GND Cable disconnected from negative (-) battery terminal 200 Ω or higher

      Below 200 Ω:

      LCL short to ground
      A49-22 (LCH) - GND Cable disconnected from negative (-) battery terminal 200 Ω or higher

      Below 200 Ω:

      LCH short to ground
      A49-21 (LCL) - +B Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      LCL +B short
      A49-22 (LCH) - +B Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      LCH +B short
      Result
      Result Proceed to
      OK A
      NG (Open circuit in main line) B
      NG (Short circuit between main line) C
      NG (Short to +B or ground) D

    A

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH Click here

    C

    CHECK FOR SHORT BETWEEN CAN BUS LINES (HEADLIGHT ECU SUB-ASSEMBLY LH - HEADLIGHT ECU SUB-ASSEMBLY RH) Click here

    D

    CHECK FOR FOR SHORT IN CAN BUS LINE (HEADLIGHT ECU SUB-ASSEMBLY LH - HEADLIGHT ECU SUB-ASSEMBLY RH) Click here

    B

  19. CHECK FOR OPEN IN CAN BUS MAIN LINES (HEADLIGHT ECU SUB-ASSEMBLY LH - HEADLIGHT ECU SUB-ASSEMBLY RH)


    1. Connect the A49 headlight ECU sub-assembly LH connector.

    2. Disconnect the A50 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
      A50-21 (LCL) - A50-22 (LCH) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR

    OK

  20. REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH


    1. Replace the headlight ECU sub-assembly RH with a new or known good one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  21. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Body Electrical > AFS > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  22. CHECK FOR DTC


    1. Turn the engine switch on (IG).

    2. Check for DTCs.

      Click here


      Body Electrical > AFS > Trouble Codes
      OK
      DTC U0242 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (HEADLIGHT ECU SUB-ASSEMBLY RH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH Click here

  23. CHECK FOR SHORT BETWEEN CAN BUS LINES (HEADLIGHT ECU SUB-ASSEMBLY LH - HEADLIGHT ECU SUB-ASSEMBLY RH)


    1. Connect the A49 headlight ECU sub-assembly LH connector.

    2. Disconnect the A50 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
      A50-21 (LCL) - A50-22 (LCH) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR

    OK

  24. REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH


    1. Replace the headlight ECU sub-assembly RH with a new or known good one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  25. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Body Electrical > AFS > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  26. CHECK FOR DTC


    1. Turn the engine switch on (IG).

    2. Check for DTCs.

      Click here


      Body Electrical > AFS > Trouble Codes
      OK
      DTC U0242 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (HEADLIGHT ECU SUB-ASSEMBLY RH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH Click here

  27. CHECK FOR FOR SHORT IN CAN BUS LINE (HEADLIGHT ECU SUB-ASSEMBLY LH - HEADLIGHT ECU SUB-ASSEMBLY RH)


    1. Disconnect the A50 headlight ECU sub-assembly RH connector.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A50-21 (LCL) - GND Cable disconnected from negative (-) battery terminal 200 Ω or higher
      A50-22 (LCH) - GND Cable disconnected from negative (-) battery terminal 200 Ω or higher
      A50-21 (LCL) - +B Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      A50-22 (LCH) - +B Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR

    OK

  28. REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH


    1. Replace the headlight ECU sub-assembly RH with a new or known good one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  29. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Body Electrical > AFS > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  30. CHECK FOR DTC


    1. Turn the engine switch on (IG).

    2. Check for DTCs.

      Click here


      Body Electrical > AFS > Trouble Codes
      OK
      DTC U0242 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (HEADLIGHT ECU SUB-ASSEMBLY RH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH Click here