METER / GAUGE SYSTEM Tachometer Malfunction

WIRING DIAGRAM

A01BHINE02

INSPECTION PROCEDURE

PROCEDURE


  1. INSPECT COMBINATION METER ASSEMBLY


    1. A01BDS8E10

      Check the input signal wave form using an oscilloscope.


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

      2. Connect the oscilloscope to terminal S (H20-14) and body ground.

      3. Start the engine.

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

        A01BEG3E02
        Item Condition
        Tester connection H20-14 (S) - Body ground
        Tool setting 5 V/DIV., 10 ms/DIV.
        Vehicle condition Ignition switch ON, engine idle speed
        OK
        The correct waveform appears as shown in the illustration.

    NG

    CHECK HARNESS AND CONNECTOR (BETWEEN ECM AND COMBINATION METER) Click here

    OK

    REPLACE COMBINATION METER ASSEMBLY

  2. CHECK HARNESS AND CONNECTOR (BETWEEN ECM AND COMBINATION METER)


    1. A01BEE5E01

      Disconnect the H20 and B9*1/B7*2/B8*3/B48*4 connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B9-4 (TACH)*1 - H20-14 (S) Always Below 1 Ω
      B7-1 (TACH)*2 - H20-14 (S) Always Below 1 Ω
      B8-7 (TACH)*3 - H20-14 (S) Always Below 1 Ω
      B48-18 (TACH)*4 - H20-14 (S) Always Below 1 Ω
      H20-14 (S) - Body ground Always 10 kΩ or higher

      *1: for 2KD-FTV

      *2: for 1TR-FE, 2TR-FE

      *3: for 5L-E

      *4: for 1KD-FTV


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM