SFI SYSTEM, Diagnostic DTC:P0197, P0198

DTC Code DTC Name
P0197 Engine Oil Temperature Sensor Low
P0198 Engine Oil Temperature Sensor High

DESCRIPTION

A thermistor, whose resistance changes in accordance with the engine oil temperature, is built into the engine oil temperature sensor. As the engine oil temperature decreases, the thermistor resistance increases and as the engine oil temperature increases, the thermistor resistance decreases. The engine oil temperature sensor is connected to the ECM. A voltage of 5 V is supplied from terminal THEO via resistor R of the ECM. Since resistor R and the engine oil temperature sensor are connected in series, both the resistance and the electrical potential of THEO are subject to change in accordance with a change in the engine oil temperature.

DTC No. DTC Detection Condition Trouble Area
P0197 Short in engine oil temperature sensor circuit (1 trip detection logic).

  • Short in engine oil temperature sensor circuit

  • Engine oil temperature sensor

  • ECM
P0198 Open in engine oil temperature sensor circuit (1 trip detection logic).

  • Open in engine oil temperature sensor circuit

  • Engine oil temperature sensor

  • ECM

WIRING DIAGRAM

A0055L4E11
*a THEO
*b ETHE
*c Engine Oil Temperature Sensor

CAUTION / NOTICE / HINT

Tech Tips

Read freeze frame data using the GTS. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE


  1. READ VALUE USING GTS (ENGINE OIL TEMPERATURE SENSOR)


    1. Connect the GTS to the DLC3.

    2. Start the engine and warm it up.

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine and ECT / Data List / Engine Oil Temperature Sensor.

    5. Read the value displayed on the GTS.

      Standard
      Between 80 and 110°C (176 and 230°F) with warm engine and engine idling
      Result
      Result Proceed to
      -40°C (-40°F) A
      Higher than 180°C (356°F) B
      Between 80 and 110°C (176 and 230°F) C

      Tech Tips


      • If there is an open circuit, the GTS indicates -40°C (-40°F).


      • If there is a short circuit, the GTS indicates higher than 180°C (356°F).


    B

    READ VALUE USING GTS (CHECK FOR SHORT IN WIRE HARNESS) Click here

    C

    CHECK FOR INTERMITTENT PROBLEMS Click here

    A

  2. READ VALUE USING GTS (CHECK FOR OPEN IN WIRE HARNESS)


    1. A0054ZIE02
      Text in Illustration
      *1 Engine Oil Temperature Sensor
      *2 ECM
      *a

      Front view of wire harness connector

      (to Engine Oil Temperature Sensor)

      Disconnect the engine oil temperature sensor connector.

    2. Connect terminals 1 and 2 of the engine oil temperature sensor connector.

    3. Connect the GTS to the DLC3.

    4. Turn the ignition switch to ON.

    5. Turn the GTS on.

    6. Enter the following menus: Powertrain / Engine and ECT / Data List / Engine Oil Temperature Sensor.

    7. Read the value displayed on the GTS.

      Standard
      Higher than 180°C (356°F)

    8. Reconnect the engine oil temperature sensor connector.


    OK

    REPLACE ENGINE OIL TEMPERATURE SENSOR Click here

    NG

  3. CHECK HARNESS AND CONNECTOR (ENGINE OIL TEMPERATURE SENSOR - ECM)


    1. Disconnect the engine oil temperature sensor connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      B51-2 - B53-89 (THEO) Always Below 1 Ω
      B51-1 - B53-90 (ETHE) Always Below 1 Ω

    4. Reconnect the engine oil temperature sensor connector.

    5. Reconnect the ECM connector.


    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE OIL TEMPERATURE SENSOR - ECM)

  4. READ VALUE USING GTS (CHECK FOR SHORT IN WIRE HARNESS)


    1. A0056AYE18
      Text in Illustration
      *1 Engine Oil Temperature Sensor
      *2 ECM

      Disconnect the engine oil temperature sensor connector.

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the GTS on.

    5. Enter the following menus: Powertrain / Engine and ECT / Data List / Engine Oil Temperature Sensor.

    6. Read the value displayed on the GTS.

      Standard
      -40°C (-40°F)

    7. Reconnect the engine oil temperature sensor connector.


    OK

    REPLACE ENGINE OIL TEMPERATURE SENSOR Click here

    NG

  5. CHECK HARNESS AND CONNECTOR (ENGINE OIL TEMPERATURE SENSOR - ECM)


    1. Disconnect the engine oil temperature sensor connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      B51-2 or B53-89 (THEO) - Body ground Always 10 kΩ or higher

    4. Reconnect the engine oil temperature sensor connector.

    5. Reconnect the ECM connector.


    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE OIL TEMPERATURE SENSOR - ECM)