AUDIO AND VISUAL SYSTEM (w/o Multi-display) Vehicle Speed Signal Circuit between Radio Receiver and Combination Meter

DESCRIPTION

Vehicle 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


  1. for 2GR-FE

    A01G5QHE01

  2. for 2AR-FE

    A01G4M4E01

INSPECTION PROCEDURE

PROCEDURE


  1. INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)


    1. A01G92YE04
      Text in Illustration
      *a

      Component with harness connected

      (Combination Meter Assembly)

      Check the output waveform.


      1. Remove the combination meter assembly with the connector still connected.

      2. Connect an oscilloscope to terminal H14-19 (+S) and body ground.

      3. Turn the engine switch on (IG).

      4. Turn a wheel slowly.

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

        Item Condition
        Measurement terminal H14-19 (+S) - 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.


    NG

    GO TO METER / GAUGE SYSTEM Click here

    OK

  2. INSPECT RADIO RECEIVER ASSEMBLY (INPUT WAVEFORM)


    1. A01G5ULE03
      Text in Illustration
      *a

      Component with harness connected

      (Radio Receiver Assembly)

      Check the input waveform.


      1. Remove the radio receiver assembly with the connector(s) still connected.

      2. Connect an oscilloscope to terminal H83-3 (SPD) and body ground.

      3. Turn the engine switch on (IG).

      4. Turn a wheel slowly.

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

        Item Condition
        Measurement terminal H83-3 (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.


    NG

    CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY - JUNCTION CONNECTOR) Click here

    OK

    REPLACE RADIO RECEIVER ASSEMBLY Click here

  3. CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY - JUNCTION CONNECTOR)


    1. Disconnect the H83 radio receiver assembly connector.

    2. Disconnect the H114 junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H83-3 (SPD) - H114-15 Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (RADIO RECEIVER ASSEMBLY - JUNCTION CONNECTOR)

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (JUNCTION CONNECTOR)