METER / GAUGE SYSTEM Engine Coolant Temperature Receiver Gauge Malfunction

WIRING DIAGRAM

A01BDGPE02

INSPECTION PROCEDURE

Tech Tips

If there is an open or short in the engine coolant temperature sensor circuit, the ECM outputs DTCs. Perform troubleshooting with the "SFI System" (1TR-FE), (2TR-FE), "ECD System" (1KD-FTV), (2KD-FTV) or (5L-E).

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER


    1. Operate the intelligent tester according to the steps on the display and select "DATA LIST".

      Engine and ECT
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Coolant Temp Coolant temperature / Min.: -40°C (-40°F), Max.: 215°C (419°F) After warming up: 80 to 95°C (176 to 203°F) If the value is -40°C (-40°F) or 140°C (284°F), sensor circuit is open or shorted.
      OK
      Coolant temperature displayed on the tester is between 80°C (176°F) and 95°C (203°F) after warming up.

    NG

    GO TO ENGINE CONTROL SYSTEM

    OK

  2. INSPECT COMBINATION METER ASSEMBLY


    1. A01BANXE01

      Disconnect the connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      B9-2 (THWO)*1 - Body ground Ignition switch ON 11 to 14 V
      B7-14 (THWO)*2 - Body ground Ignition switch ON 11 to 14 V
      B10-8 (THWO)*3 - Body ground Ignition switch ON 11 to 14 V
      B47-16 (THWO)*4 - Body ground Ignition switch ON 11 to 14 V

      *1: for 2KD-FTV

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

      *3: for 5L-E

      *4: for 1KD-FTV


    NG

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

    OK

  3. INSPECT COMBINATION METER ASSEMBLY


    1. A01BC7QE01
      A01BATNE01

      Check the input signal wave form.


      1. Remove the combination meter with the connectors still connected.

      2. Connect the oscilloscope to terminal S (H20-17) and body ground.

      3. Start the engine.

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

        Item Condition
        Tester connection H20-17 (S) - Body ground
        Tool setting 5 V/DIV., 100 ms/DIV.
        Vehicle condition Ignition switch ON, coolant temperature 50°C to 120°C (122°F to 248.0°F)

      Tech Tips

      As engine coolant temperature rises, the period A shown in the illustration becomes longer.

      Except Middle East
      Engine Coolant Temperature A
      Less than 50°C (122.0°F) 96.304 to 100.304 ms
      83°C (181.4°F) 231.472 to 235.472 ms
      120°C (248.0°F) 383.024 to 387.024 ms
      Middle East
      Engine Coolant Temperature A
      Less than 70°C (158.0°F) 178.224 to 182.224 ms
      95°C (203.0°F) 282.624 to 286.624 ms
      120°C (248.0°F) 383.024 to 387.024 ms

    NG

    REPLACE ECM

    OK

    REPLACE COMBINATION METER ASSEMBLY

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


    1. A01BH3UE01

      Disconnect the H20 and B9 (*1), B7 (*2), B10 (*3) connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H20-17 (S) - B9-2 (THWO)*1 Always Below 1 Ω
      H20-17 (S) - B7-14 (THWO)*2 Always Below 1 Ω
      H20-17 (S) - B10-8 (THWO)*3 Always Below 1 Ω
      H20-17 (S) - B47-16 (THWO)*4 Always Below 1 Ω
      B9-2 (THWO)*1 - Body ground Always 10 kΩ or higher
      B7-14 (THWO)*2 - Body ground Always 10 kΩ or higher
      B10-8 (THWO)*3 - Body ground Always 10 kΩ or higher
      B47-16 (THWO)*4 - 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 COMBINATION METER ASSEMBLY