AUDIO AND VISUAL SYSTEM(for Radio and Display Type) Vehicle Speed Signal Circuit between Radio Receiver and Combination Meter

DESCRIPTION

The radio and display receiver assembly receives a vehicle speed signal from the combination meter assembly to control the ASL function.

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 its respective system based on this 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

B003S4XE01

CAUTION / NOTICE / HINT

Note

Check that the wire harness is properly installed and does not have any sharp bends, pinching or loose connections.

PROCEDURE


  1. CHECK COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)


    1. B003LH0C33
      *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 G8-19 (+S) and body ground.

      3. Turn the ignition switch to ON.

      4. Turn a wheel slowly.

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

        Item Condition
        Measurement terminal G8-19 (+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.

      Result
      Proceed to
      OK
      NG

    NG

    GO TO METER / GAUGE SYSTEM Click here

    OK

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


    1. Disconnect the G100 radio and display receiver assembly connector.

    2. Disconnect the G8 combination meter assembly connector.

    3. w/ Smart Entry and Start System:

      Disconnect the G16 certification ECU (smart key ECU assembly) connector.

    4. Disconnect the G33 body ECU connector.

    5. Disconnect the G49 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G100-17 (SPD) - G8-19 (+S) Always Below 1 Ω
      G100-17 (SPD) or G8-19 (+S) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR