AUTOMATIC HEADLIGHT BEAM LEVEL CONTROL SYSTEM Vehicle Speed Signal Circuit

DESCRIPTION

The headlight leveling ECU receives the vehicle speed signal from the combination meter.

WIRING DIAGRAM

A01QUITE04
*1 Combination Meter Assembly
*2 Headlight Leveling ECU Assembly

CAUTION / NOTICE / HINT

Tech Tips

After replacing the headlight leveling ECU, initialization of the ECU is necessary.

Click here

PROCEDURE


  1. READ VALUE USING GTS (VEHICLE SPEED)


    1. Using the GTS, read the Data List.

      Click here


      Body Electrical > HL AutoLeveling > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Vehicle Speed Vehicle speed 0 to 327.67 km/h Actual vehicle speed -

      Body Electrical > HL AutoLeveling > Data List
      Tester Display
      Vehicle Speed
      OK
      The display is as specified in the normal condition column.
      Result
      Proceed to
      OK
      NG

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    NG

  2. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - HEADLIGHT LEVELING ECU ASSEMBLY)


    1. Disconnect the G16 combination meter connector.

    2. Disconnect the A67 headlight leveling ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G16-6 (+S) - A67-16 (SPDR) Always Below 1 Ω
      G16-6 (+S) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK COMBINATION METER ASSEMBLY


    1. A01QU2KC01
      *a

      Component with harness connected

      (Combination Meter Assembly)

      Remove the combination meter with its connector still connected.

      Click here

    2. Connect an oscilloscope to the combination meter connector.

    3. Check the waveform.

      Measurement Condition
      Item Content
      Terminal No. (Symbol) G16-6 (+S) - Body ground
      Tool setting 5 V/DIV., 20 ms./DIV.
      Condition Vehicle is driven at approximately 20 km/h (12 mph)
      Result
      Proceed to
      Waveform is as shown in the illustration
      Waveform is not as shown in the illustration

      Tech Tips

      When the system is functioning normally, one wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows


    Waveform is as shown in the illustration

    REPLACE HEADLIGHT LEVELING ECU ASSEMBLY Click here

    Waveform is not as shown in the illustration

    GO TO METER / GAUGE SYSTEM Click here