ADAPTIVE HIGH BEAM SYSTEM, Diagnostic DTC:B2490, B2491

DTC Code DTC Name
B2490 Left LED Fan Circuit
B2491 Right LED Fan Circuit

DESCRIPTION

If a malfunction is detected in a LED array fan, the headlight light control ECU sub-assembly sends a LED array fan malfunction signal to the No. 1 headlight ECU sub-assembly via LIN communication. The No. 1 headlight ECU sub-assembly LH stores DTC B2490 and B2491.

DTC No. Detection Item DTC Detection Condition Trouble Area
B2490 Left LED Fan Circuit LED array fan LH abnormal

  • Headlight unit LH

  • Headlight unit assembly LH

  • Headlight light control ECU sub-assembly LH
B2491 Right LED Fan Circuit LED array fan RH abnormal

  • Headlight unit RH

  • Headlight unit assembly RH

  • Headlight light control ECU sub-assembly RH

WIRING DIAGRAM

A003MLUE04

PROCEDURE


  1. 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

  2. CHECK FOR DTC


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Operate the light control switch to turn on the low beam headlights.

    4. Turn the GTS on.

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

    6. Check for DTCs.


      Body Electrical > AHS > Trouble Codes
      OK
      DTC B2490 and B2491 are not output.
      Result
      Result Proceed to
      OK A
      NG (DTC B2490 is output) B
      NG (DTC B2491 is output) C

    A

    USE SIMULATION METHOD TO CHECK Click here

    C

    INSPECT HEADLIGHT UNIT ASSEMBLY RH Click here

    B

  3. INSPECT HEADLIGHT UNIT ASSEMBLY LH

    A003L6TC03
    *a

    Component without harness connected

    (to Headlight Unit LH)

    		 *b

    Component without harness connected

    (to Headlight Light Control ECU Sub-assembly LH)

    1. Remove the headlight assembly LH.

      Click here

    2. Remove the headlight unit LH.

      Click here

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K-5 (FH) - E-13 Always Below 1 Ω
      K-7 (FG) - E-6 Always Below 1 Ω
      K-6 (FL) - E-7 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HEADLIGHT UNIT ASSEMBLY LH Click here

    OK

  4. REPLACE HEADLIGHT UNIT LH


    1. Replace the headlight unit LH with a new or known good one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  5. 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

  6. CHECK FOR DTC


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Operate the light control switch to turn on the low beam headlights.

    4. Turn the GTS on.

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

    6. Check for DTCs.


      Body Electrical > AHS > Trouble Codes
      OK
      DTC B2490 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (HEADLIGHT UNIT LH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT LIGHT CONTROL ECU SUB-ASSEMBLY LH Click here

  7. INSPECT HEADLIGHT UNIT ASSEMBLY RH

    A003L6TC03
    *a

    Component without harness connected

    (to Headlight Unit RH)

    		 *b

    Component without harness connected

    (to Headlight Light Control ECU Sub-assembly RH)

    1. Remove the headlight assembly RH.

      Click here

    2. Remove the headlight unit RH.

      Click here

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K-5 (FH) - E-13 Always Below 1 Ω
      K-7 (FG) - E-6 Always Below 1 Ω
      K-6 (FL) - E-7 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HEADLIGHT UNIT ASSEMBLY RH Click here

    OK

  8. REPLACE HEADLIGHT UNIT RH


    1. Replace the headlight unit RH with a new or known good one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  9. 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

  10. CHECK FOR DTC


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Operate the light control switch to turn on the low beam headlights.

    4. Turn the GTS on.

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

    6. Check for DTCs.


      Body Electrical > AHS > Trouble Codes
      OK
      DTC B2491 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (HEADLIGHT UNIT RH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT LIGHT CONTROL ECU SUB-ASSEMBLY RH Click here