LIGHTING SYSTEM, Diagnostic DTC:U0242

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

DESCRIPTION

This DTC is output when a headlight ECU sub-assembly RH internal malfunctioning or the communication malfunction between headlight ECU sub-assembly LH and headlight sub-assembly RH is 10 seconds or more. The headlight ECU sub-assembly LH stores DTC U0242.

DTC Code DTC Detection Condition Trouble Area
U0242

Either of the following conditions is met:


  • Headlight ECU sub-assembly RH internal malfunctioning

  • The communication malfunction between headlight ECU sub-assembly LH and headlight ECU sub-assembly RH is 10 seconds or more.

  • Headlight ECU sub-assembly LH

  • Headlight ECU sub-assembly RH

  • Harness or connector

WIRING DIAGRAM


  1. for Single Beam Headlight without AFS (Adaptive Front-lighting System)

    B002BPKE01
    *1 LINL
    *2 Headlight ECU Sub-assembly LH
    *3 Headlight ECU Sub-assembly RH
    *4 LIN Communication Line

  2. for Single Beam Headlight with AFS (Adaptive Front-lighting System)

    B002BAME05

  3. for Triple Beam Headlight (w/o Adaptive High Beam System)

    B002BVME06

  4. for Triple Beam Headlight (w/ Adaptive High Beam System [for LHD])

    B002BKXE07

  5. for Triple Beam Headlight (w/ Adaptive High Beam System [for RHD])

    B002BKXE08

CAUTION / NOTICE / HINT

Note

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. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC U0242 is not output.
      Result
      Result Proceed to
      OK A
      NG (for Single Beam Headlight without AFS [Adaptive Front-lighting System]) B
      NG (for Single Beam Headlight with AFS [Adaptive Front-lighting System]) C
      NG (for Triple Beam Headlight [w/o Adaptive High Beam System]) D
      NG (for Triple Beam Headlight [w/ Adaptive High Beam System]) E

    A

    USE SIMULATION METHOD TO CHECK Click here

    C

    CHECK HARNESS AND CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY LH - HEADLIGHT ECU SUB-ASSEMBLY RH) Click here

    D

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

    E

    CHECK FOR DTC Click here

    B

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


    1. Disconnect the B16 headlight ECU sub-assembly LH connector.

    2. Disconnect the B15 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
      B16-20 (LINL) - B15-20 (LINL) Always Below 1 Ω
      B16-20 (LINL) or B15-20 (LINL) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HEADLIGHT ECU SUB-ASSEMBLY RH


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

    2. Clear the DTCs Click here.

    3. Check for DTCs Click here.

      OK
      DTC U0242 is not output.

    OK

    END (HEADLIGHT ECU SUB-ASSEMBLY RH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH Click here

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


    1. Disconnect the B16 headlight ECU sub-assembly LH connector.

    2. Disconnect the B15 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
      B16-19 (LINS) - B15-19 (LINS) Always Below 1 Ω
      B16-19 (LINS) or B15-19 (LINS) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK CAN BUS LINE (HEADLIGHT ECU SUB-ASSEMBLY LH - HEADLIGHT ECU SUB-ASSEMBLY RH)


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

    2. Disconnect the B16 headlight ECU sub-assembly LH connector.

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

      Standard Resistance:
      Tester Connection Condition Specified Condition Result
      B16-22 (LCH) - B16-21 (LCL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω 132 Ω or more: Open circuit in main bus lines
      Below 108 Ω: Short circuit between bus lines
      Result
      Result Proceed to
      OK A
      NG (Open circuit in main lines) B
      NG (Short circuit between main lines) C

    B

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

    C

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

    A

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


    1. Disconnect the B15 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 Result
      B15-22 (LCH) - GND Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: LCH short to ground
      B15-21 (LCL) - GND Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: LCL short to ground
      B15-22 (LCH) - +B Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ: LCH +B short
      B15-21 (LCL) - +B Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ: LCL +B short

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY LH - HEADLIGHT ECU SUB-ASSEMBLY RH)

    OK

  7. CHECK HEADLIGHT ECU SUB-ASSEMBLY RH


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

    2. Clear the DTCs Click here.

    3. Check for DTCs Click here.

      OK
      DTC U0242 is not output.

    OK

    END (HEADLIGHT ECU SUB-ASSEMBLY RH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH Click here

  8. CHECK CAN BUS LINE (HEADLIGHT ECU SUB-ASSEMBLY RH - HEADLIGHT ECU SUB-ASSEMBLY LH)


    1. Reconnect the B16 headlight ECU sub-assembly LH connector.

    2. Disconnect the B15 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
      B15-22 (LCH) - B15-21 (LCL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY LH - HEADLIGHT ECU SUB-ASSEMBLY RH)

    OK

  9. CHECK HEADLIGHT ECU SUB-ASSEMBLY RH


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

    2. Clear the DTCs Click here.

    3. Check for DTCs Click here.

      OK
      DTC U0242 is not output.

    OK

    END (HEADLIGHT ECU SUB-ASSEMBLY RH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH Click here

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


    1. Reconnect the B16 headlight ECU sub-assembly LH connector.

    2. Disconnect the B15 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
      B15-22 (LCH) - B15-21 (LCL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY LH - HEADLIGHT ECU SUB-ASSEMBLY RH)

    OK

  11. CHECK HEADLIGHT ECU SUB-ASSEMBLY RH


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

    2. Clear the DTCs Click here.

    3. Check for DTCs Click here.

      OK
      DTC U0242 is not output.

    OK

    END (HEADLIGHT ECU SUB-ASSEMBLY RH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH Click here

  12. CHECK FOR DTC


    1. Check for DTCs Click here.

      OK
      DTC U1002 is not output.

    NG

    GO TO DTC U1002 Click here

    OK

  13. CHECK HARNESS AND CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY RH - NO. 6 CAN JUNCTION CONNECTOR)


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

    2. Disconnect the B15 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
      B15-22 (LCH) - B15-21 (LCL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  14. CHECK HARNESS AND CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY LH - NO. 6 CAN JUNCTION CONNECTOR)


    1. Disconnect the B16 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
      B16-22 (LCH) - B16-21 (LCL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  15. CHECK HEADLIGHT ECU SUB-ASSEMBLY RH


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

    2. Clear the DTCs Click here.

    3. Check for DTCs Click here.

      OK
      DTC U0242 is not output.

    OK

    END (HEADLIGHT ECU SUB-ASSEMBLY RH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH Click here