СИСТЕМА ECD, Diagnostic DTC:22

DTC Code DTC Name
22 Engine Coolant Temperature Sensor Circuit Malfunction

DESCRIPTION

The engine coolant temperature sensor senses the coolant temperature. A thermistor built into the sensor changes the resistance value according to the coolant temperature. The lower the coolant temperature, the greater the thermistor resistance value, and the higher the coolant temperature, the lower the thermistor resistance value (see Fig. 1).

The engine coolant temperature sensor is connected to the ECM. The 5 V power source voltage in the ECM is applied to the engine coolant temperature sensor from the terminal THW via resistor R. That is, the resistor R and the engine coolant temperature sensor are connected in series. When the resistance value of the engine coolant temperature sensor changes in accordance with changes in the coolant temperature, the potential at the terminal THW also changes. Based on this signal, the ECM increases the fuel injection volume to improve driveability during cold engine operation.

A01DZUUE05
DTC No. DTC Detection Condition Trouble Area
22 Open or short in engine coolant temperature sensor circuit for 0.5 sec. or more

  • Open or short in engine coolant temperature sensor circuit

  • Engine coolant temperature sensor

  • ECM

WIRING DIAGRAM

A01DV37E01

INSPECTION PROCEDURE

Tech Tips


  • If DTCs that are related to different systems are output simultaneously while terminal E2 is used as a ground terminal, terminal E2 may be open.

  • Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

When using intelligent tester:

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (ENGINE COOLANT TEMPERATURE)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch ON.

    3. Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.

      Result
      Display Proceed to
      -40°C (-40°F) A
      140°C (284°F) or more B
      The same as actual engine coolant temperature C

      Tech Tips

      When DTC 22 is present, the type of malfunction can be determined based on the engine coolant temperature (see below).

      Temperature Displayed Malfunction
      -40°C (-40°F) Open circuit
      140°C (284°F) or more Short circuit

    B

    CHECK WIRE HARNESS (FOR SHORT) Click here

    C

    CHECK FOR INTERMITTENT PROBLEMS

    A

  2. CHECK WIRE HARNESS (FOR OPEN)


    1. A01DYFTE04

      Disconnect the W1 engine coolant temperature sensor connector.

    2. Connect terminals 1 and 2 of the engine coolant temperature sensor harness side connector.

    3. Turn the ignition switch ON.

    4. Read the temperature value on the intelligent tester.

      Temperature
      140°C (284°F) or more

    OK

    REPLACE ENGINE COOLANT TEMPERATURE SENSOR

    NG

  3. CHECK ECM (FOR OPEN)


    1. A01DVSUE08

      Connect between terminals THW and E2 of the ECM connector.

    2. Turn the ignition switch ON.

    3. Read the temperature value on the intelligent tester.

      Temperature
      140°C (284°F) or more

    NG

    REPLACE ECM

    OK

    REPAIR OR REPLACE HARNESS AND CONNECTOR

  4. CHECK WIRE HARNESS (FOR SHORT)


    1. A01E1D2E01

      Disconnect the W1 engine coolant temperature sensor connector.

    2. Turn the ignition switch ON.

    3. Read the temperature value on the intelligent tester.

      Temperature
      -40°C (- 40°F)

    OK

    REPLACE ENGINE COOLANT TEMPERATURE SENSOR

    NG

  5. CHECK ECM (FOR SHORT)


    1. A01E0XZE07

      Disconnect the E22 ECM connector.

    2. Turn the ignition switch ON.

    3. Read the temperature value on the intelligent tester.

      Temperature
      -40°C (-40°F)

    NG

    REPLACE ECM

    OK

    REPAIR OR REPLACE HARNESS AND CONNECTOR

When not using intelligent tester:

PROCEDURE


  1. CHECK ECM (THW VOLTAGE)


    1. A01E2VTE57

      Turn the ignition switch ON.

    2. Measure the voltage of the ECM connector.

      Standard voltage
      Tester Connection Condition Specified Condition
      E22-4 (THW) - E22-9 (E2) 20°C (68°F) 0.2 to 3.8 V
      E22-4 (THW) - E22-9 (E2) 80°C (176°F) 0.1 to 1.5 V

    OK

    CHECK FOR INTERMITTENT PROBLEMS

    NG

  2. INSPECT ENGINE COOLANT TEMPERATURE SENSOR


    1. A01DUZ2E03

      Measure the resistance of the sensor.

      OK
      The resistance value is within the acceptable range shown in the illustration.

      Note

      When checking the engine coolant temperature sensor in water, do not allow water to enter the terminals. After checking, wipe the sensor dry.


    NG

    REPLACE ENGINE COOLANT TEMPERATURE SENSOR

    OK

  3. CHECK WIRE HARNESS (ECM - ENGINE COOLANT TEMPERATURE SENSOR)


    1. A01DVP9E08

      Disconnect the W1 engine coolant temperature sensor connector.

    2. Disconnect the E22 ECM connector.

    3. Measure the resistance of the wire harness side connectors.

      Standard resistance
      Tester Connection Specified Condition
      W1-1 - E22-4 (THW) Below 1 Ω
      W1-2 - E22-9 (E2) Below 1 Ω
      E22-4 (THW) - E22-9 (E2) 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

    REPLACE ECM