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 light control ECU sub-assembly to the headlight ECU sub-assembly via LIN communication. The headlight ECU sub-assembly LH outputs DTCs B2490 and B2491.

DTC Code DTC Detection Condition Trouble Area
B2490 LED array fan LH malfunction

  • Headlight unit LH LED array fan LH)

  • Headlight unit assembly LH (

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

  • Headlight unit RH (LED array fan RH)

  • Headlight unit assembly RH

  • Headlight light control ECU sub-assembly RH

WIRING DIAGRAM

B001B1BE11

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

    3. Check for DTCs Click here.

      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 ASSEMBLY RH Click here

    B

  3. REPLACE HEADLIGHT UNIT ASSEMBLY 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. B00187CE02
      Text in Illustration
      *a

      Component without harness connected

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

      Component without harness connected

      (Headlight Light Control ECU Sub-assembly LH Side 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

    NG

    REPLACE HEADLIGHT UNIT LH Click here

    OK

  4. REPLACE HEADLIGHT UNIT LH


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


    NEXT

  5. CLEAR DTC


    1. Clear the DTCs Click here.


    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.

      OK
      DTC B2490 is not output.

    OK

    END (HEADLIGHT UNIT LH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT LIGHT CONTROL ECU SUB-ASSEMBLY LH Click here

  7. REPLACE HEADLIGHT UNIT ASSEMBLY RH


    1. Remove the headlight assembly RH Click here.

    2. Remove the headlight unit assembly LH from the headlight assembly RH Click here.

    3. Remove the headlight light control ECU sub-assembly RH Click here.

    4. B0018CGE02
      Text in Illustration
      *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 Side 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

    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.


    NEXT

  9. CLEAR DTC


    1. Clear the DTCs Click here.


    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.

      OK
      DTC B2491 is not output.

    OK

    END (HEADLIGHT UNIT RH WAS DEFECTIVE)

    NG

    REPLACE HEADLIGHT LIGHT CONTROL ECU SUB-ASSEMBLY RH Click here