ECD SYSTEM, Diagnostic DTC:P0115, P0116, P0117, P0118

DTC Code DTC Name
P0115 Coolant Temperature Sensor Plausibility Test
P0116 Coolant Temperature Sensor Gradient Test
P0117 Short to GND in Coolant Temperature Sensor Circuit
P0118 Open or Short to B+ in Coolant Temperature Sensor Circuit

DESCRIPTION

The thermistor built into the engine coolant temperature sensor changes its resistance value according to the engine coolant temperature. When the engine coolant temperature is low, the resistance increases. When the engine coolant temperature is high, the resistance drops. The variations in the resistance are reflected as a voltage change at the ECM.

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 through a resistor that is inside the ECM.

The resistor 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 engine coolant temperature, the voltage at the ECM terminal also changes. Based on this signal, the ECM increases the fuel injection volume to improve drivability while the engine is cold.

DTC No. DTC Detection Condition Trouble Area Possible to Detect
Ignition Switch Engine Run
P0115

Both of the following condition (a) and (b) is met:

(a) Engine coolant temperature sensor output augmentation is less than 5°C (41°F), for 20 min. after engine start.

(b) The engine coolant temperature is below 30°C (86°F).

(2 trip detection logic)

  • Engine coolant temperature sensor

  • Engine cooling system (Thermostat, cooling fan, etc.)

 - -
P0116

The engine coolant temperature sensor output suddenly changes for 15 sec. or more.

(1 trip detection logic)

  • Engine coolant temperature sensor

  • Engine coolant temperature sensor circuit

  • ECM

 ON ON
P0117

Engine coolant temperature sensor output is more than 150°C (302°F) (less than 0.1 V) for 5 sec. or more.

(1 trip detection logic)

  • Engine coolant temperature sensor

  • Engine coolant temperature sensor circuit

  • ECM

 ON ON
P0118

Engine coolant temperature sensor output is less than -50°C (-58°F) (more than 4.97 V) for 5 sec. or more.

(1 trip detection logic)

  • Engine coolant temperature sensor

  • Engine coolant temperature sensor circuit

  • ECM

 ON ON

FAIL-SAFE

DTC No. Trouble Area Possible to Detect
P0115

  • Stops the EGR.

  • Stops the A/C.

  • Cooling fan operates at high speed.

  • Water temperature warning light illuminates.

  • EGR component: Next engine start.

  • Other component: Normal condition is restored.
P0116

  • Stops the EGR.

  • Stops the A/C.

  • Cooling fan operates at high speed.

  • Water temperature warning light illuminates.

  • EGR component: Next engine start.

  • Other component: Normal condition is restored.
P0117

  • Stops the EGR.

  • Stops the A/C.

  • Cooling fan operates at high speed.

  • Water temperature warning light illuminates.

  • EGR component: Next engine start.

  • Other component: Normal condition is restored.
P0118

  • Stops the EGR.

  • Stops the A/C.

  • Cooling fan operates at high speed.

  • Water temperature warning light illuminates.

  • EGR component: Next engine start.

  • Other component: Normal condition is restored.

WIRING DIAGRAM

A0137PBE02

INSPECTION PROCEDURE

Tech Tips


  • When DTC P0115, P0116, P0117 or P0118 is detected, check the engine coolant temperature by selecting the following menu items on the intelligent tester: Powertrain / Engine and ECT / Data List / Coolant Temp.

  • If the ECM is replaced, variant coding (variant coding indicates the presence of vehicle accessory items, A/C, etc.) should always be performed Click here.

  • Before removing the ECM and the peripheral parts, wait at least 3 minute after turning the ignition switch off (If the cooling fan is operating, remove the ECM and the peripheral parts after the fan stops.).

PROCEDURE


  1. CHECK DTC OUTPUT (P0115, P0116, P0117 AND/OR P0118)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to the ON position and turn the intelligent tester on.

    3. Select the following menu items: Powertrain / Engine and ECT / DTC.

    4. Read the DTCs.

      Result
      Display (DTC Output) Proceed To
      Only P0115 A
      P0115, P0116, P0117 and/or P0118 B

    B

    READ VALUE OF INTELLIGENT TESTER (ENGINE COOLANT TEMPERATURE) Click here

    A

  2. CHECK COOLING SYSTEM (THERMOSTAT, COOLING FAN ETC.)


    1. Check the cooling system (thermostat, cooling fan, etc.).

      OK
      The cooling system functions normally.

    NG

    REPAIR OR REPLACE COOLING SYSTEM

    OK

  3. REPLACE ENGINE COOLANT TEMPERATURE SENSOR


    NEXT

  4. CHECK IF DTC RECURS (P0115, P0116, P0117 AND/OR P0118)


    1. Connect the intelligent tester to the DLC3.

    2. Clear the DTC Click here.

    3. Cool down the engine (engine coolant temperature is below 30°C (86°F)).

    4. Start the engine and turn the intelligent tester on.

    5. Run the engine for 20 minutes.

    6. Select the following menu items: Powertrain / Engine and ECT / DTC.

    7. Read the DTCs displayed on the intelligent tester.

      Result
      Display (DTC Output) Proceed To
      No output A
      DTC P0115, P0116, P0117 and/or P0118 B

    B

    REPLACE ECM

    A

    END

  5. READ VALUE OF INTELLIGENT TESTER (ENGINE COOLANT TEMPERATURE)


    1. Warm up the engine.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to the ON position and turn the intelligent tester on.

    4. Select the following menu items: Powertrain / Engine and ECT / Coolant Temp.

    5. Read the value.

      OK
      The displayed temperature is the same as the actual engine coolant temperature, and the sensor output does not fluctuate significantly.

      Tech Tips


      • After the engine warms up, the engine coolant temperature is usually 75 to 95°C (167 to 203°F).

      • If there is an open circuit, the intelligent tester indicates less than -40°C (-40°F).

      • If there is a short circuit to ground, the intelligent tester indicates more than 150°C (302°F).


    NG

    CHECK ENGINE COOLANT TEMPERATURE SENSOR Click here

    OK

    CHECK FOR INTERMITTENT PROBLEMS

  6. CHECK ENGINE COOLANT TEMPERATURE SENSOR


    1. A0136F7E01

      Disconnect the B34 engine coolant temperature sensor connector.

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

      Standard resistance
      Tester Connection Specified Condition
      1 - 2 The resistance value is within the acceptable range shown in the illustration.

    NG

    REPLACE ENGINE COOLANT TEMPERATURE SENSOR

    OK

  7. INSPECT ECM (VOLTAGE)


    1. A0135VQE02

      Disconnect the B34 engine coolant temperature sensor connector.

    2. Turn the ignition switch to the ON position.

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

      Standard voltage
      Tester Connection Specified Condition
      Engine coolant temperature sensor (B34-1) - Body ground 4.7 to 5.3 V

    NG

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

    OK

  8. CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)


    1. A0138E9E01

      Disconnect the B54 ECM connector.

    2. Disconnect the B34 engine coolant temperature sensor connector.

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

      Standard resistance
      Check for open
      Tester Connection Specified Condition
      ETHW (B54-2) - Engine coolant temperature sensor (B34-2) Below 1 Ω
      Check for short
      Tester Connection Specified Condition
      ETHW (B54-2) or Engine coolant temperature sensor (B34-2) - Body ground 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. REPLACE ENGINE COOLANT TEMPERATURE SENSOR


    NEXT

  10. READ VALUE OF INTELLIGENT TESTER (ENGINE COOLANT TEMPERATURE)


    1. Warm up the engine.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to the ON position and turn the intelligent tester on.

    4. Select the following menu items: Powertrain / Engine and ECT / Coolant Temp.

    5. Read the value.

      OK
      The displayed temperature is the same as the actual engine coolant temperature, and the sensor output does not fluctuate significantly.

      Tech Tips


      • If there is an open circuit, the intelligent tester indicates less than -40°C (-40°F).

      • If there is a short circuit to ground, the intelligent tester indicates more than 150°C (302°F).


    NG

    REPLACE ECM

    OK

    END

  11. CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)


    1. A013800E01

      Disconnect the B53 ECM connector.

    2. Disconnect the B34 engine coolant temperature sensor connector.

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

      Standard resistance
      Check for open
      Tester Connection Specified Condition
      THW (B53-37) - Engine coolant temperature sensor (B34-1) Below 1 Ω
      Check for short
      Tester Connection Specified Condition
      THW (B53-37) or Engine coolant temperature sensor (B34-1) - Body ground 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  12. CHECK POWER SOURCE CIRCUIT


    1. Check that the battery voltage, ECM power source voltage, and the ground condition of the ECM are normal.

      OK
      The battery voltage, ECM power source voltage, and the ground condition of the ECM are normal.

      Tech Tips

      Make sure that the battery is not discharged during the inspection.


    NG

    REPAIR POWER SOURCE CIRCUIT

    OK

    REPLACE ECM