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 ECU sub-assembly RH is 10 seconds or more.

The headlight ECU sub-assembly LH outputs DTC U0242.

DTC Code DTC Detection Condition Trouble Area
U0242

Either conditions:


  • 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. w/ Adaptive High Beam System

    B0019LNE02

  2. w/o Adaptive High Beam System

    B0018GZE04

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  2. CHECK FOR DTC


    1. Turn the engine switch on (IG).

    2. Turn on the headlights using the headlight dimmer switch.

    3. Check for DTCs Click here.

      OK
      DTC U0242 are not output.
      Result
      Result Proceed to
      OK A
      NG (w/ Adaptive High Beam System) B
      NG (w/o Adaptive High Beam System) (for LHD) C
      NG (w/o Adaptive High Beam System) (for RHD) D

    A

    USE SIMULATION METHOD TO CHECK Click here

    C

    GO TO CAN COMMUNICATION SYSTEM Click here

    D

    GO TO CAN COMMUNICATION SYSTEM Click here

    B

  3. CHECK HARNESS AND CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY LH - NO. 7 CAN JUNCTION CONNECTOR


    1. Cable disconnected from negative (-) battery terminal

    2. Disconnect the E164 No. 7 CAN junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E164-13 - E164-3 Cable disconnected from negative (-) battery terminal Below 1 Ω
      E164-14 - E164-4 Cable disconnected from negative (-) battery terminal 10 kΩ or higher

    NG

    HARNESS AND CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY - NO. 7 CAN JUNCTION CONNECTOR Click here

    OK

  4. CHECK HEADLIGHT ECU SUB-ASSEMBLY RH - POWERSOURCE AND BODY GROUND)


    1. Cable disconnected from negative (-) battery terminal

    2. Disconnect the A65 headlight ECU sub-assembly RH connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A65-4 (IG) - Body ground Engine switch on (IG) 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A65-12 (GND) - Body ground Always Below 1 Ω

    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 normally functioning one Click here.

    2. Turn the engine switch on (IG).

    3. Turn on the headlights using the headlight dimmer switch.

    4. Clear the DTCs Click here.

    5. Check for DTCs Click here.


    OK

    END (HEADLIGHT ECU SUB-ASSEMBLY RH WAS DEFECTIVE)

    NG

  6. CHECK FOR DTC


    1. Reconnect the E164 No. 7 CAN junction connector.

    2. Turn the engine switch on (IG).

    3. Turn on the headlights using the headlight dimmer switch.

    4. Clear the DTCs Click here.

    5. Check for DTCs Click here.

      OK
      DTC U0242 are not output.

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH Click here

  7. HARNESS AND CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY - NO. 7 CAN JUNCTION CONNECTOR


    1. Reconnect the E164 No. 7 CAN junction connector.

    2. Disconnect the A64 headlight ECU sub-assembly LH connector.

    3. Disconnect the A65 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
      A64-22 (LCH ) - A64-21 (LCL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
      A64-22 (LCH ) - A64-21 (LCL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

    OK

    CHECK HEADLIGHT ECU SUB-ASSEMBLY LH Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR