SFI SYSTEM, Diagnostic DTC:P0115, P0117, P0118

DTC Code DTC Name
P0115 Engine Coolant Temperature Circuit Malfunction
P0117 Engine Coolant Temperature Circuit Low Input
P0118 Engine Coolant Temperature Circuit High Input

DESCRIPTION

A thermistor, whose resistance value varies according to the engine coolant temperature, is built into the engine coolant temperature sensor. The structure of the sensor and its connection to the ECM are the same as those of the intake air temperature sensor.

Tech Tips

When DTC P0115, P0117 or P0118 is stored, the ECM enters fail-safe mode. During fail-safe mode, the engine coolant temperature is estimated to be 80°C (176°F) by the ECM. Fail-safe mode continues until a pass condition is detected.

DTC No. DTC Detection Condition Trouble Area
P0115 An open or short in the engine coolant temperature sensor circuit for 0.5 seconds (1 trip detection logic).
  • Open or short in engine coolant temperature sensor circuit

  • Engine coolant temperature sensor

  • ECM

P0117 A short in the engine coolant temperature sensor circuit for 0.5 seconds (1 trip detection logic).
  • Short in engine coolant temperature sensor circuit

  • Engine coolant temperature sensor

  • ECM

P0118 An open in the engine coolant temperature sensor circuit for 0.5 seconds (1 trip detection logic).
  • Open in engine coolant temperature sensor circuit

  • Engine coolant temperature sensor

  • ECM

Tech Tips

When any of these DTCs are output, check the engine coolant temperature using the GTS. Enter the following menus on the GTS: Powertrain / Engine / Data List / All Data / Coolant Temp.

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

MONITOR DESCRIPTION

The engine coolant temperature sensor is used to monitor the engine coolant temperature. The engine coolant temperature sensor has a thermistor with a resistance that varies according to the temperature of the engine coolant. When the coolant temperature is low, the resistance in the thermistor increases. When the temperature is high, the resistance drops. These variations in resistance are reflected in the output voltage from the sensor. The ECM monitors the sensor voltage and uses this value to calculate the engine coolant temperature. When the sensor output voltage deviates from the normal operating range, the ECM interprets this as a fault in the engine coolant temperature sensor circuit and stores a DTC.

Example:

If the sensor output voltage is higher than 4.91 V for 0.5 seconds or more, the ECM determines that there is an open in the engine coolant temperature sensor circuit, and stores DTC P0118. Conversely, if the voltage output is less than 0.14 V for 0.5 seconds or more, the ECM determines that there is a short in the sensor circuit, and stores DTC P0117.

MONITOR STRATEGY

Frequency of Operation Continuous

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 0.5 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: P0115, P0117 or P0118.

  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

A01G5Q6E42

INSPECTION PROCEDURE

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.

  • If DTC P0117 is stored, check that the engine does not overheat (the DTC P0117 may be stored due to engine overheating).

PROCEDURE


  1. READ VALUE USING GTS (COOLANT TEMP)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine / Data List / All Data / Coolant Temp.

    5. Read the value displayed on the GTS.

      Standard value
      Between 75 and 100°C (167 and 212°F) with warm engine.
      Result
      Result Proceed to
      -40°C (-40°F) A
      140°C (284°F) B
      Between 75 and 100°C (167 and 212°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 140°C (284°F).


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


    1. Disconnect the engine coolant temperature sensor connector.

      A01G66XE49
      Text in Illustration
      *1 Engine Coolant Temperature Sensor *2 ECM
      *a

      Front view of wire harness connector

      (to Engine Coolant Temperature Sensor)

      - -
    2. Connect terminals 1 (E2) and 2 (THW) of the engine coolant temperature sensor connector on the wire harness side.

    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 / Coolant Temp.

    7. Read the value displayed on the GTS.

      Standard value
      140°C (284°F)

      Tech Tips

      Perform "Inspection After Repair" after replacing the engine coolant temperature sensor Click here.


    NG
    OK
  3. CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)


    1. Disconnect the engine coolant temperature sensor connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D43-2 (THW) - D23-114 (THW) Always Below 1 Ω
      D43-1 (E2) - D23-117 (ETHW) Always Below 1 Ω

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


    1. A01G8BDE02
      Text in Illustration
      *1 Engine Coolant Temperature Sensor
      *2 ECM

      Disconnect the engine coolant 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 / Coolant Temp.

    6. Read the value displayed on the GTS.

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

      Tech Tips

      Perform "Inspection After Repair" after replacing the engine coolant temperature sensor Click here.


    NG
    OK
  5. CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)


    1. Disconnect the engine coolant temperature sensor connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D43-2 (THW) or D23-114 (THW) - Body ground Always 10 kΩ or higher

    NG
    OK