LIGHTING SYSTEM Speed Signal Circuit

DESCRIPTION

The headlight leveling ECU assembly receives front wheel speed sensor signals from the skid control ECU.

WIRING DIAGRAM

A015YUPE10

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK DTC (VEHICLE STABILITY CONTROL SYSTEM)


    1. Check that vehicle stability control system DTCs are not output.

      OK
      VSC system DTC is not output.

    NG

    GO TO VEHICLE STABILITY CONTROL SYSTEM Click here

    OK

  2. CHECK SPEED SENSOR SIGNAL WAVEFORM


    1. A0161X5E03
      Text in Illustration
      *1

      Component with harness connected

      (Headlight Leveling ECU Assembly)

      Check the speed signal waveform.


      1. Connect an oscilloscope to terminals A64-5 (SPDL) and body ground or terminals A64-6 (SPDR) and body ground.

      2. Turn the engine switch on (IG).

      3. Turn the front wheels slowly.

    2. Check the signal waveform according to the condition(s) in the table below.

      Item Condition
      Tool setting 5 V / DIV., 20 ms / DIV.
      Vehicle condition Wheels being rotated
      OK
      The waveform is similar to that shown in the illumination.

      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.


    NG

    CHECK HARNESS AND CONNECTOR (HEADLIGHT LEVELING ECU ASSEMBLY - SKID CONTROL ECU) Click here

    OK

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

  3. CHECK HARNESS AND CONNECTOR (HEADLIGHT LEVELING ECU ASSEMBLY - SKID CONTROL ECU)


    1. Disconnect the A64 headlight leveling ECU assembly connector.

    2. Disconnect the A62 brake actuator assembly (skid control ECU) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A62-10 (FRO) - A64-6 (SPDR) Always Below 1 Ω
      A62-9 (FLO) - A64-5 (SPDL) Always Below 1 Ω
      A64-6 (SPDR) - Body ground Always 10 kΩ or higher
      A64-5 (SPDL) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT HEADLIGHT LEVELING ECU ASSEMBLY (OUTPUT VOLTAGE)


    1. Disconnect the A62 skid control ECU connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A62-9 (FLO) - Body ground Engine switch on (IG) 10 to 14 V
      A62-10 (FRO) - Body ground Engine switch on (IG) 10 to 14 V

    NG

    REPLACE HEADLIGHT LEVELING ECU ASSEMBLY Click here

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU) Click here