LIGHTING SYSTEM, Diagnostic DTC:B243D, B243E

DTC Code DTC Name
B243D Left Low Beam Fan Malfunction
B243E Right Low Beam Fan Malfunction

DESCRIPTION

This DTC is output when the low beam fan is malfunctioning and the low beam illumination is dark.

The headlight ECU sub-assembly LH outputs DTC B243D and B243E

DTC No. Detection Item DTC Detection Condition Trouble Area
B243D Left Low Beam Fan Malfunction The headlight assembly LH low beam fan is malfunctioning and the low beam illumination is dark.

  • Headlight LED unit assembly LH

  • Headlight unit assembly LH

  • Headlight ECU sub-assembly LH
B243E Right Low Beam Fan Malfunction The headlight assembly RH low beam fan is malfunctioning and the low beam illumination is dark.

  • Headlight LED unit assembly RH

  • Headlight unit assembly RH

  • Headlight ECU sub-assembly RH

WIRING DIAGRAM

B006P6ZE09

CAUTION / NOTICE / HINT

Note

After the headlight ECU sub-assembly LH is replaced, vehicle information registration and initialization are necessary.

Click here

PROCEDURE


  1. CHECK FOR DTC


    1. Clear the DTCs.

      Click here


      Body Electrical > HL AutoLeveling > Clear DTCs

    2. Check for DTCs.

      Click here


      Body Electrical > HL AutoLeveling > Trouble Codes
      OK
      DTC B243D or B243E output does not occur.
      Result
      Result Proceed to
      OK A
      NG (DTC B243D is output) B
      NG (DTC B243E is output) C

    A

    USE SIMULATION METHOD TO CHECK Click here

    C

    CHECK HEADLIGHT UNIT ASSEMBLY RH Click here

    B

  2. CHECK HEADLIGHT UNIT ASSEMBLY LH


    1. B006ONFC01
      *a

      Component without harness connected

      (to Headlight ECU Sub-assembly LH)
      *b

      Component without harness connected

      (to Headlight LED Unit Assembly LH)

      Remove the headlight unit assembly LH.

      for ALPHARD:

      Click here

      for VELLFIRE:

      Click here

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

      Standard Resistance
      w/ Cornering Light
      Tester Connection Condition Specified Condition
      B-4 - E-1 Always Below 1 Ω
      B-15 - E-2 Always Below 1 Ω
      B-14 - E-3 Always Below 1 Ω
      w/o Cornering Light
      Tester Connection Condition Specified Condition
      B-6 - E-1 Always Below 1 Ω
      B-15 - E-2 Always Below 1 Ω
      B-14 - E-3 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HEADLIGHT UNIT ASSEMBLY LH for ALPHARD: REPLACE HEADLIGHT UNIT ASSEMBLY LH Click here
    REPLACE HEADLIGHT UNIT ASSEMBLY LH for VELLFIRE: REPLACE HEADLIGHT UNIT ASSEMBLY LH Click here

    OK

  3. CHECK HEADLIGHT ECU SUB-ASSEMBLY LH


    1. B006L0IC03
      *a

      Component without harness connected

      (to Headlight LED Unit Assembly LH)

      Remove the headlight LED unit assembly LH.

      for ALPHARD:

      Click here

      for VELLFIRE:

      Click here

    2. Connect the headlight ECU sub-assembly LH connectors.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      E-1 - E-3 Low beam headlights illuminated 4.5 to 5.5 V
      E-2 - E-3 Low beam headlights illuminated 4.5 to 5.5 V
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE HEADLIGHT LED UNIT ASSEMBLY LH for ALPHARD: REPLACE HEADLIGHT LED UNIT ASSEMBLY LH Click here
    REPLACE HEADLIGHT LED UNIT ASSEMBLY LH for VELLFIRE: REPLACE HEADLIGHT LED UNIT ASSEMBLY LH Click here

    NG

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH Click here

  4. CHECK HEADLIGHT UNIT ASSEMBLY RH


    1. B006ONFC01
      *a

      Component without harness connected

      (to Headlight ECU Sub-assembly RH)
      *b

      Component without harness connected

      (to Headlight LED Unit Assembly RH)

      Remove the headlight unit assembly RH.

      for ALPHARD:

      Click here

      for VELLFIRE:

      Click here

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

      Standard Resistance
      w/ Cornering Light
      Tester Connection Condition Specified Condition
      B-4 - E-1 Always Below 1 Ω
      B-15 - E-2 Always Below 1 Ω
      B-14 - E-3 Always Below 1 Ω
      w/o Cornering Light
      Tester Connection Condition Specified Condition
      B-6 - E-1 Always Below 1 Ω
      B-15 - E-2 Always Below 1 Ω
      B-14 - E-3 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HEADLIGHT UNIT ASSEMBLY RH for ALPHARD: REPLACE HEADLIGHT UNIT ASSEMBLY RH Click here
    REPLACE HEADLIGHT UNIT ASSEMBLY RH for VELLFIRE: REPLACE HEADLIGHT UNIT ASSEMBLY RH Click here

    OK

  5. CHECK HEADLIGHT UNIT ASSEMBLY RH


    1. B006L0IC03
      *a

      Component without harness connected

      (to Headlight LED Unit Assembly RH)

      Remove the headlight LED unit assembly RH.

      for ALPHARD:

      Click here

      for VELLFIRE:

      Click here

    2. Connect the headlight ECU sub-assembly RH connectors.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      E-1 - E-3 Low beam headlights illuminated 4.5 to 5.5 V
      E-2 - E-3 Low beam headlights illuminated 4.5 to 5.5 V
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE HEADLIGHT LED UNIT ASSEMBLY RH for ALPHARD: REPLACE HEADLIGHT LED UNIT ASSEMBLY RH Click here
    REPLACE HEADLIGHT LED UNIT ASSEMBLY RH for VELLFIRE: REPLACE HEADLIGHT LED UNIT ASSEMBLY RH Click here

    NG

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH Click here