AUDIO AND VISUAL SYSTEM (w/o Navigation System) Vehicle Speed Signal Circuit between Radio Receiver and Combination Meter

DESCRIPTION

Speed signals are received from the combination meter assembly and used to cancel "Bluetooth" function operation.

The radio receiver assembly recognizes that the vehicle is being driven and makes it impossible to connect or register a "Bluetooth" device while driving.

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 following diagram will not operate normally.

WIRING DIAGRAM

A0160GVE14

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY - COMBINATION METER ASSEMBLY)


    1. Disconnect the radio receiver assembly and combination meter assembly connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J108-3 (SPD) - J34-5 (+S) Always Below 1 Ω
      J108-3 (SPD) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)


    1. Reconnect the combination meter assembly connector.

    2. A0160URE10

      Check the input waveform.


      1. Connect an oscilloscope to terminal J108-3 (SPD) and body ground.

      2. Turn the engine switch on (IG).

      3. Turn a wheel slowly.

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

        A0162TDE07
        Item Condition
        Measurement terminal J108-3 (SPD) - Body ground
        Tool setting 5 V/DIV., 20 ms./DIV.
        Vehicle condition Wheel being rotated
        OK
        The waveform is similar to that 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.

        Text in Illustration
        *1

        Front view of wire harness connector

        (to Radio Receiver Assembly)

    NG

    REPLACE COMBINATION METER ASSEMBLY Click here

    OK

    REPLACE RADIO RECEIVER ASSEMBLY Click here