LIGHTING SYSTEM, Diagnostic DTC:U0242

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

DESCRIPTION

The No. 1 headlight ECU sub-assembly LH stores this DTC when the No. 1 headlight ECU sub-assembly RH detects an internal malfunction or if a communication malfunction occurs between No. 1 headlight ECU sub-assembly LH and No. 1 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:


  • No. 1 headlight ECU sub-assembly RH internal malfunction

  • Communication malfunction occurs between No. 1 headlight ECU sub-assembly LH and No. 1 headlight ECU sub-assembly RH for 10 seconds or more

  • No. 1 headlight ECU sub-assembly LH

  • No. 1 headlight ECU sub-assembly RH

  • Harness or connector

 -

WIRING DIAGRAM


  1. w/o Adaptive High Beam System

    A003O0UE18
    *1 LINL
    *2 No. 1 Headlight ECU Sub-assembly LH
    *3 No. 1 Headlight ECU Sub-assembly RH
    *4 LIN Communication Line

  2. w/ Adaptive High Beam System

    A003P7NE11

CAUTION / NOTICE / HINT

Note


  • If the No. 1 headlight ECU sub-assembly LH has been replaced, it is necessary to synchronize the vehicle information and initialize the No. 1 headlight ECU sub-assembly LH.

    Click here

  • After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

    Click here

PROCEDURE


  1. CONFIRM MODEL


    1. Choose the model to be inspected.

      Result
      Result Proceed to
      w/o Adaptive High Beam System A
      w/ Adaptive High Beam System B

    B

    CLEAR DTC Click here

    A

  2. CLEAR DTC


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS 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

    NEXT

  3. CHECK FOR DTC


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS 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

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  4. CHECK HARNESS AND CONNECTOR (NO. 1 HEADLIGHT ECU SUB-ASSEMBLY LH - NO. 1 HEADLIGHT ECU SUB-ASSEMBLY RH)


    1. Disconnect the A15 No. 1 headlight ECU sub-assembly LH connector.

    2. Disconnect the A16 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
      A15-20 (LINL) - A16-20 (LINL) Always Below 1 Ω
      A15-20 (LINL) or A16-20 (LINL) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE NO. 1 HEADLIGHT ECU SUB-ASSEMBLY RH


    1. Replace the No. 1 headlight ECU sub-assembly RH with a new or known good one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  6. CLEAR DTC


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS 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

    NEXT

  7. CHECK FOR DTC


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS 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

    OK

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

    NG

    REPLACE NO. 1 HEADLIGHT ECU SUB-ASSEMBLY LH Click here

  8. CLEAR DTC


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / AHS / Trouble Codes.

    5. Clear the DTCs.


      Body Electrical > AHS > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  9. CHECK FOR DTC


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / AHS / Trouble Codes.

    5. Check for DTCs.


      Body Electrical > AHS > 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. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Pre-Crash 2 / Trouble Codes.

    5. Check for DTCs.


      Body Electrical > Pre-Crash 2 > Trouble Codes

      Tech Tips

      When pre-crash safety system DTC U1002 is output, check that the local bus is functioning normally by performing the diagnostic procedure for U1002.

      OK
      DTC U1002 is not output.
      Result
      Proceed to
      OK
      NG

    NG

    GO TO DTC U1002 Click here

    OK

  11. CHECK HARNESS AND CONNECTOR (NO. 1 HEADLIGHT ECU SUB-ASSEMBLY RH - NO. 4 CAN JUNCTION CONNECTOR)

    A003M9AC19
    *a

    Component without harness connected

    (No. 1 Headlight ECU Sub-assembly RH)

    1. Turn the power switch off.

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

    3. Disconnect the A16 No. 1 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
      A16-21 (LCL) - A16-22 (LCH) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω

      Tech Tips

      If the result is not as specified, a malfunction in a CAN communication line is suspected.

    5. Connect the A16 No. 1 headlight ECU sub-assembly RH connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (CAN BUS LINE)

    OK

  12. CHECK HARNESS AND CONNECTOR (NO. 1 HEADLIGHT ECU SUB-ASSEMBLY LH - NO. 4 CAN JUNCTION CONNECTOR)

    A003M9AC20
    *a

    Component without harness connected

    (No. 1 Headlight ECU Sub-assembly LH)

    1. Disconnect the A15 No. 1 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
      A15-21 (LCL) - A15-22 (LCH) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω

      Tech Tips

      If the result is not as specified, a malfunction in a CAN communication line is suspected.

    3. Connect the A15 No. 1 headlight ECU sub-assembly LH connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (CAN BUS LINE)

    OK

  13. REPLACE NO. 1 HEADLIGHT ECU SUB-ASSEMBLY RH


    1. Replace the No. 1 headlight ECU sub-assembly RH with a new or known good one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  14. CLEAR DTC


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / AHS / Trouble Codes.

    5. Clear the DTCs.


      Body Electrical > AHS > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  15. CHECK FOR DTC


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / AHS / Trouble Codes.

    5. Check for DTCs.


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

    OK

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

    NG

    REPLACE NO. 1 HEADLIGHT ECU SUB-ASSEMBLY LH Click here