NAVIGATION SYSTEM(except Sedan) Vehicle Speed Signal Circuit between Stereo Component Amplifier and Combination Meter

DESCRIPTION

The stereo component amplifier 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 the respective systems 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


  1. for 1ND-TV

    A012I59E01

  2. for 1NR-FE

    A012JX5E01

  3. for 1ZR-FAE

    A012M4KE01

PROCEDURE


  1. INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)


    1. Check the output waveform.

      A012KUDC01
      *a

      Component with harness connected

      (Combination Meter Assembly)

      		 - -

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

      2. Connect an oscilloscope to terminal E46-6 (+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 E46-6 (+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. INSPECT STEREO COMPONENT AMPLIFIER ASSEMBLY (INPUT WAVEFORM)


    1. Check the input waveform.

      A012N82C02
      *a

      Component with harness connected

      (Stereo Component Amplifier Assembly)

      		 - -

      1. Remove the stereo component amplifier assembly with the connector(s) still connected.

      2. Connect an oscilloscope to terminal E92-11 (SPD) 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 E92-11 (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.

      Result
      Proceed to
      OK
      NG

    OK

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

    NG

  3. CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER ASSEMBLY - JUNCTION CONNECTOR)


    1. Disconnect the E92 stereo component amplifier assembly connector.

    2. Disconnect the E54 junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E92-11 (SPD) - E54-11 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK JUNCTION CONNECTOR


    1. Disconnect the E54 junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E54-11 - E54-7 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE JUNCTION CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)


    1. Disconnect the E54 junction connector.

    2. Disconnect the 3D instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E54-7 - 3D-20 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


    1. Remove the instrument panel junction block assembly.

    2. A012HYTC01
      *a

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3D-20 - 3D-38 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (COMBINATION METER ASSEMBLY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY for LHD: Click here
    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY for RHD: Click here