METER / GAUGE SYSTEM Tachometer Malfunction

DESCRIPTION

In this circuit, the combination meter assembly receives engine speed signals from the ECM. The meter CPU displays the engine speed, which is calculated based on the data received from the ECM.

WIRING DIAGRAM

A01DYP6E01
A01DYP6E02
A01DYP6E03
A01DYP6E04
A01DYP6E05

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK COMBINATION METER ASSEMBLY

    A01E2LTE01
    Text in Illustration
    *a

    Front view of wire harness connector

    (to Combination Meter Assembly)

    1. Disconnect the C25 combination meter assembly connector.

    2. Using an oscilloscope, check the signal waveform of the meter.

      Item Condition
      Tester Connection C25-7 (S) - Body ground
      Tool Setting 5 V/DIV., 10 msec./DIV.
      Condition Engine idling
      OK
      The waveform displayed is as shown in the illustration.

      Tech Tips

      As the engine speed increases, the wavelength shortens.


    NG

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

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here

  2. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)


    • *1: for 1TR-FE, 2TR-FE

    • *2: for 1KD-FTV, 2KD-FTV

    • *3: for 1GR-FE

    • *4: for 5L-E


    1. Disconnect the C25 combination meter assembly connector.

    2. Disconnect the E10*1 or E5*2 or E13*3 or E21*4 ECM connector.

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

      Standard Resistance
      for 1TR-FE, 2TR-FE
      Tester Connection Condition Specified Condition
      C25-7 (S) - E10-1 (TACH) Always Below 1 Ω
      C25-7 or E10-1 (TACH) - Body ground Always 10 kΩ or higher
      for 1KD-FTV w/o DPF, 2KD-FTV w/o DPF
      Tester Connection Condition Specified Condition
      C25-7 (S) - E5-4 (TACH) Always Below 1 Ω
      C25-7 (S) or E5-4 (TACH) - Body ground Always 10 kΩ or higher
      for 1KD-FTV w/ DPF, 2KD-FTV w/ DPF
      Tester Connection Condition Specified Condition
      C25-7 (S) - E31-18 (TACH) Always Below 1 Ω
      C25-7 (S) or E31-18 (TACH) - Body ground Always 10 kΩ or higher
      for 1GR-FE
      Tester Connection Condition Specified Condition
      C25-7 (S) - E13-1 (TACH) Always Below 1 Ω
      C25-7 or E13-1 (TACH) - Body ground Always 10 kΩ or higher
      for 5L-E
      Tester Connection Condition Specified Condition
      C25-7 (S) - E21-7 (TACH) Always Below 1 Ω
      C25-7 or E21-7 (TACH) - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      NG A
      OK (for 1TR-FE, 2TR-FE, 1GR-FE) B
      OK (for 1KD-FTV, 2KD-FTV, 5L-E) C

    B

    GO TO SFI SYSTEM

    C

    GO TO ECD SYSTEM

    A

    REPAIR OR REPLACE HARNESS OR CONNECTOR