METER / GAUGE SYSTEM Speedometer Malfunction

DESCRIPTION

The combination meter assembly controls the speedometer in accordance with vehicle speed signals from the brake actuator assembly.

WIRING DIAGRAM

A01CHMHE01

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (VEHICLE SPEED)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

    4. Enter the following menus: Chassis / ABS/VSC/TRC / Data List.

    5. According to the display on the tester, read the Data List.

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Vehicle Speed

      Maximum wheel speed sensor reading/

      Min.: 0 km/h (0 mph)

      Max.: 326 km/h (202 mph)

      		 Vehicle stopped: 0 km/h (0 mph) When driving at constant speed: No large fluctuations
      OK
      Vehicle speed displayed on the tester is approximately the same as the actual vehicle speed.

    NG

    GO TO ANTI-LOCK BRAKE SYSTEM Click here

    OK

  2. INSPECT COMBINATION METER ASSEMBLY (OUTPUT VOLTAGE)


    1. Disconnect the brake actuator assembly connector.

    2. A01CGTTE05
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Brake Actuator Assembly)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      B9-21 (SP1) - Body ground Ignition switch ON 20 to 28 V

    NG

    CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - BRAKE ACTUATOR ASSEMBLY) Click here

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here

  3. INSPECT BRAKE ACTUATOR ASSEMBLY (INPUT WAVEFORM)


    1. A01CIS4E04
      Text in Illustration
      *a

      Component with harness connected

      (Combination Meter Assembly)
      *b Waveform

      Check the input waveform.


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

      2. Connect an oscilloscope to terminal C18-22 (S1) and body ground.

      3. Turn the ignition switch to ON.

      4. Turn the wheel slowly.

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

        Standard
        Item Condition
        Tool setting 5 V/DIV., 20 ms./DIV.
        Condition Driving at approximately 20 km/h (12 mph)
        OK
        The waveform is displayed as shown in the illustration.

        Tech Tips

        As the vehicle speed increases, the cycle of the waveform narrows.


    NG

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here

  4. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - BRAKE ACTUATOR ASSEMBLY)


    1. Disconnect the C18 combination meter assembly connector.

    2. Disconnect the B9 brake actuator assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C18-22 (S1) - B9-21 (SP1) Always Below 1 Ω
      C18-22 (S1) or B9-21 (SP1) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here