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 control computer assembly RH internal malfunctioning or the communication malfunction between headlight control computer assembly LH and headlight control computer assembly RH is 10 seconds or more.

The headlight control computer assembly LH outputs DTC U0242.

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

  • Either conditions:


    • Headlight control computer assembly RH internal malfunctioning

    • The communication malfunction between headlight control computer assembly LH and headlight control computer assembly RH is 10 seconds or more.

  • Headlight control computer assembly LH

  • Headlight control computer assembly RH

  • Harness or connector

WIRING DIAGRAM


  1. w/ Adaptive High Beam System

    B002DDIE01

  2. w/o Adaptive High Beam System

    B002DKZE02

CAUTION / NOTICE / HINT

Note

After the headlight control computer assembly LH (main) is replaced, vehicle information registration and initialization are necessary.

Click here

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Body Electrical > AFS > Clear DTCs
      Result
      Proceed to
      NEXT

    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 CONTROL COMPUTER ASSEMBLY LH - NO. 1 CAN JUNCTION CONNECTOR)


    1. Cable disconnected from negative (-) battery terminal.

    2. Disconnect the A39 No. 1 CAN junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A39-13 - A39-3 Cable disconnectedfrom negative (-) batteryterminal Below 1 Ω
      A39-12 - A39-1 Cable disconnectedfrom negative (-) batteryterminal 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (HEADLIGHT CONTROL COMPUTER ASSEMBLY RH - NO. 1 CAN JUNCTION CONNECTOR) Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (HEADLIGHT CONTROL COMPUTER ASSEMBLY RH - POWER SOURCE AND BODY GROUND)


    1. Cable disconnected from negative (-) battery terminal.

    2. Disconnect the A30 headlight control computer assembly RH connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A30-4 (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 Switch Condition Specified Condition
      A30-12 (GND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE HEADLIGHT CONTROL COMPUTER ASSEMBLY RH


    1. Replace the headlight control computer 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

      Result
      Proceed to
      OK
      NG

    OK

    HEADLIGHT CONTROL COMPUTER ASSEMBLY RH (HEADLIGHT ECU SUB-ASSEMBLY RH WAS DEFECTIVE)

    NG

  6. CHECK FOR DTC


    1. Reconnect the A39 No. 1 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


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

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

    REPLACE HEADLIGHT CONTROL COMPUTER ASSEMBLY LH Click here

  7. CHECK HARNESS AND CONNECTOR (HEADLIGHT CONTROL COMPUTER ASSEMBLY RH - NO. 1 CAN JUNCTION CONNECTOR)


    1. Reconnect the A39 No. 1 CAN junction connector.

    2. Disconnect the A29 headlight control computer assembly LH connector.

    3. Disconnect the A30 headlight control computer assembly RH connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      A30-22 (LCH) - A30-21 (LCH) Cable disconnected from negative (-) battery terminal 54 Ω to 69 Ω
      A30-22 (LCH) - A30-21 (LCH) Cable disconnected from negative (-) battery terminal 54 Ω to 69 Ω
      Result
      Proceed to
      OK
      NG

    OK

    CHECK HEADLIGHT CONTROL COMPUTER ASSEMBLY LH

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR