LIGHTING SYSTEM Vehicle Speed Signal Circuit

DTC Code DTC Name
Vehicle Speed Signal Circuit

DESCRIPTION

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

WIRING DIAGRAM

E183425E01

CAUTION / NOTICE / HINT

Tip:

After replacing the headlight leveling ECU, initialization of the ECU is necessary (Click here).

PROCEDURE

  1. READ VALUE USING INTELLIGENT TESTER (VEHICLE SPEED)

    1. Using the intelligent tester, read the Data List (Click here).

      Table 1. HL Auto Leveling

      Tester Display

      Measurement Item/Range

      Normal Condition

      Diagnostic Note

      Vehicle Speed

      Vehicle speed / 0 to 327.67 km/h

      A value similar to the actual vehicle speed is displayed

      -

      OK

      The display is as specified in the normal condition column.

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    (Click here)

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

    1. U123662E03

      Disconnect the H62 combination meter connector.

    2. Disconnect the A49 headlight leveling ECU connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H62-3 (+S) - A49-16 (SPDR)

      Always

      Below 1 Ω

      H62-3 (+S) - Body ground

      Always

      10 kΩ or higher
      Table 2. Text in Illustration

      *1

      Front view of wire harness connector

      (to Combination Meter Assembly)

      *2

      Front view of wire harness connector

      (to Headlight Leveling ECU Assembly)

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  3. CHECK COMBINATION METER ASSEMBLY

    1. U123976E03

      Remove the combination meter with its connector still connected (Click here).

      Table 3. Text in Illustration

      *1

      Component with harness connected

      (Combination Meter Assembly)

    2. Connect an oscilloscope to the combination meter connector.

    3. Check the waveform.

      Table 4. Measurement Condition

      Item

      Content

      Terminal No. (Symbol)

      H62-3 (+S) - Body ground

      Tool setting

      5 V/DIV., 20 ms./DIV.

      Condition

      Vehicle is driven at approximately 20 km/h (12 mph)

      OK

      Waveform is as shown in the illustration.

      Tip:

      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.

      Table 5. Result

      Result

      Proceed to

      OK (for LHD)

      A

      OK (for RHD)

      B

      NG

      C

    REPLACE HEADLIGHT LEVELING ECU ASSEMBLY

    (Click here)

    REPLACE HEADLIGHT LEVELING ECU ASSEMBLY

    (Click here)

    GO TO METER / GAUGE SYSTEM

    (Click here)