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 assembly. 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

MONITOR DESCRIPTION

The ECM monitors the engine oil temperature sensor and uses the sensor voltage to calculate the engine oil temperature. If the output voltage from the sensor deviates from the standard range, the ECM determines that the engine oil temperature sensor has malfunctioned and stores a DTC.

Example:

If the engine oil temperature sensor output voltage is higher than 4.91 V for 5 seconds or more, the ECM determines that the engine oil temperature sensor circuit is open and stores DTC P0198. If the engine oil temperature sensor output voltage is lower than 0.14 V for 5 seconds or more, the ECM determines that the engine oil temperature sensor circuit is shorted and stores DTC P0197.

CONFIRMATION DRIVING PATTERN


  1. Connect the GTS to the DLC3.

  2. Turn the engine switch on (IG) and turn the GTS on.

  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).

  4. Turn the engine switch off and wait for at least 30 seconds.

  5. Turn the engine switch on (IG) and turn the GTS on.

  6. Wait 10 seconds or more.

  7. Enter the following menus: Powertrain / Engine / Trouble Codes.

  8. Read the pending DTCs.

    Tech Tips


    • If a pending DTC is output, the system is malfunctioning.

    • If a pending DTC is not output, perform the following procedure.

  9. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

  10. Input the DTC: P0197 or P0198.

  11. Check the DTC judgment result.

    GTS Display Description
    NORMAL

    • DTC judgment completed

    • System normal
    ABNORMAL

    • DTC judgment completed

    • System abnormal
    INCOMPLETE

    • DTC judgment not completed

    • Perform driving pattern after confirming DTC enabling conditions
    N/A

    • Unable to perform DTC judgment

    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    Tech Tips


    • If the judgment result shows NORMAL, the system is normal.

    • If the judgment result shows ABNORMAL, the system has a malfunction.

    • If the judgment result shows INCOMPLETE or N/A, perform the Confirmation Driving Pattern and check the DTC judgment result again.

WIRING DIAGRAM

A01GMYKE07

INSPECTION PROCEDURE

Tech Tips

Read freeze frame data using the GTS. Freeze frame data records the engine condition when malfunctions are detected. 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 / Data List / All Data / Engine Oil Temperature Sensor.

    5. Read the value displayed on the GTS.

      Standard value
      Between 80 and 110°C (176 and 230°F) with warm engine and engine idling
      Result
      Result Proceed to
      -40°C (-40°F) A
      More than 164°C (327°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 more than 164°C (327°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. A01GLLEE01
      Text in Illustration
      *1 Engine Oil Temperature Sensor
      *2 ECM
      *a

      Front view of wire harness connector

      (to Engine Oil Temperature Sensor)

      Disconnect the E59 connector.

    2. Connect terminals OT+ and OT- of the engine oil temperature sensor connector.

    3. Connect the GTS to the DLC3.

    4. Turn the engine switch on (IG).

    5. Turn the GTS on.

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

    7. Read the value displayed on the GTS.

      Standard value
      More than 164°C (327°F).

    NG

    CHECK HARNESS AND CONNECTOR (ENGINE OIL TEMPERATURE SENSOR - ECM) Click here

    OK

    CONFIRM GOOD CONNECTION TO SENSOR, IF OK, REPLACE ENGINE OIL TEMPERATURE SENSOR Click here

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


    1. Disconnect the E59 engine oil temperature sensor connector.

    2. Disconnect the E1 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
      E59-2 (OT+) - E1-20 (THEO) Always Below 1 Ω
      E59-1 (OT-) - E1-28 (E2) Always Below 1 Ω

    NG

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

    OK

    CONFIRM GOOD CONNECTION TO SENSOR, IF OK, REPLACE ECM Click here

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


    1. A01GJ07E06
      Text in Illustration
      *1 Engine Oil Temperature Sensor
      *2 ECM

      Disconnect the E59 engine oil temperature sensor connector.

    2. Connect the GTS to the DLC3.

    3. Turn the engine switch on (IG).

    4. Turn the GTS on.

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

    6. Read the value displayed on the GTS.

      Standard value
      -40°C (-40°F)

    NG

    CHECK HARNESS AND CONNECTOR (ENGINE OIL TEMPERATURE SENSOR - ECM) Click here

    OK

    REPLACE ENGINE OIL TEMPERATURE SENSOR Click here

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


    1. Disconnect the E59 engine oil temperature sensor connector.

    2. Disconnect the E1 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
      E59-2 (OT+) or E1-20 (THEO) - Body ground Always 10 kΩ or higher

    NG

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

    OK

    REPLACE ECM Click here