VEHICLE PROXIMITY NOTIFICATION SYSTEM Speed Signal Circuit

DESCRIPTION

The vehicle approaching speaker controller receives the vehicle speed signal from the combination meter assembly.

Tech Tips

  • A voltage of 12 V or 5 V is output from each ECU and then input to the combination meter assembly. The signal is changed to a pulse signal at the transistor in the combination meter assembly. Each ECU controls the respective system based on the pulse signal.

  • If a short occurs in any of the ECUs or in the wire harness connected to an ECU, all systems in the diagram below will not operate normally.

WIRING DIAGRAM

A011Y2HE01

INSPECTION PROCEDURE

PROCEDURE

  1. INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)

    1. Check the input waveform.

      A011YQ4E06

      1. Remove the combination meter assembly with the connector(s) still connected.

      2. Connect an oscilloscope to terminal I18-9 (+S) and body ground.

      3. Turn the power switch on (IG).

      4. Turn the wheel slowly.

      5. 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 Wheel being rotated
        Text in Illustration
        *a

        Component with harness connected

        (Combination Meter Assembly)
        OK
        The waveform is displayed 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.

    NG

    GO TO METER / GAUGE SYSTEM Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (VEHICLE APPROACHING SPEAKER CONTROLLER - COMBINATION METER ASSEMBLY)

    1. Disconnect the I71 vehicle approaching speaker controller connector.

    2. Disconnect the I18 combination meter assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I71-6 (SPD) - I18-9 (+S) Always Below 1 Ω
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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