ADAPTIVE HIGH BEAM SYSTEM, Diagnostic DTC:B2490, B2491

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

DESCRIPTION

This DTC is output when there is a malfunction in the LED array fan. When the LED array fan malfunctions, an LED array fan malfunction signal is sent from the headlight control computer assembly to the headlight ECU sub-assembly via LIN communication. The headlight control computer assembly LH outputs DTCs B2490 and B2491.

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

  • Headlight unit LH

  • Headlight unit LH LED array fan LH

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

  • Headlight unit RH

  • Headlight unit LH LED array fan RH

  • Headlight light control ECU sub-assembly RH

WIRING DIAGRAM

B002CJ0E10

CAUTION / NOTICE / HINT

Note

If the headlight control computer assembly LH has been replaced, it is necessary to synchronize the vehicle information and initialize the headlight control computer assembly LH.

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

    3. Check for DTCs.

      Click here


      Body Electrical > AFS > Trouble Codes
      OK
      DTC B2490 and B2491 are not output.
      Result
      Result Proceed to
      OK A
      NG (DTC B2439 is output) B
      NG (DTC B243A is output) C

    A

    USE SIMULATION METHOD TO CHECK Click here

    C

    REPLACE HEADLIGHT UNIT RH Click here

    B

  3. REPLACE HEADLIGHT UNIT LH


    1. Remove the headlight assembly LH.

      Click here

    2. Remove the headlight unit assembly LH from the headlight assembly LH.

      Click here

    3. Remove the headlight light control ECU sub-assembly LH.

      Click here

    4. B002DLKC03
      *a

      Component without harness connected

      (Headlight Unit RH (Additional Fan LH) Side Connector)
      *b

      Component without harness connected

      (Headlight Light Control ECU Sub-assembly LH Connector)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K-5 - L-1 Always Below 1 Ω
      K-7 - L-3 Always Below 1 Ω
      K-6 - L-2 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HEADLIGHT UNIT LH Click here

    OK

  4. REPLACE HEADLIGHT UNIT ASSEMBLY LH


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

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  5. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Body Electrical > AFS > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  6. CHECK FOR DTC


    1. Turn the engine switch on (IG).

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

    3. Check for DTCs.

      Click here


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

    OK

    END (HEADLIGHT UNIT ASSEMBLY LH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT CONTROL COMPUTER ASSEMBLY LH Click here

  7. REPLACE HEADLIGHT UNIT RH


    1. Remove the headlight assembly RH.

      Click here

    2. Remove the headlight unit assembly RH from the headlight assembly RH.

      Click here

    3. Remove the headlight control computer assembly RH.

      Click here

    4. B002DLKC03
      *a

      Component without harness connected

      (Headlight Unit RH (Additional Fan RH) Side Connector)
      *b

      Component without harness connected

      (Headlight Light Control ECU Sub-assembly RH Connector)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K-5 - L-1 Always Below 1 Ω
      K-7 - L-3 Always Below 1 Ω
      K-6 - L-2 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HEADLIGHT UNIT RH Click here

    OK

  8. REPLACE HEADLIGHT UNIT ASSEMBLY RH


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

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  9. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Body Electrical > AFS > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  10. CHECK FOR DTC


    1. Turn the engine switch on (IG).

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

    3. Check for DTCs.

      Click here


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

    OK

    END (HEADLIGHT UNIT ASSEMBLY RH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT CONTROL COMPUTER ASSEMBLY RH Click here