Dtc P0115 Engine Coolant Temperature Circuit Malfunction

Engine Hybrid System. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25
2Tr-Fe Engine Control. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25

DESCRIPTION

MONITOR DESCRIPTION

MONITOR STRATEGY

CONFIRMATION DRIVING PATTERN

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING INTELLIGENT TESTER (COOLANT TEMP)

READ VALUE USING INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS)

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

READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS)

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

DTC P0115 Engine Coolant Temperature Circuit Malfunction

DTC P0117 Engine Coolant Temperature Circuit Low Input

DTC 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.
HINT:
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. The ECM continues operating in fail-safe mode until a pass condition is detected.

DTC No.
DTC Detection Condition
Trouble Area
P0115
Open or short in the engine coolant temperature sensor circuit for 0.5 seconds (Engine coolant temperature sensor voltage is below 0.14 V or higher than 4.91 V) (1 trip detection logic).
  1. Open or short in engine coolant temperature sensor circuit
  2. Engine coolant temperature sensor
  3. ECM
P0117
Short in the engine coolant temperature sensor circuit for 0.5 seconds (Engine coolant temperature sensor voltage is below 0.14 V [Higher than 140°C (284°F)]) (1 trip detection logic).
  1. Short in engine coolant temperature sensor circuit
  2. Engine coolant temperature sensor
  3. ECM
P0118
Open in the engine coolant temperature sensor circuit for 0.5 seconds (Engine coolant temperature sensor voltage is higher than 4.91 V [Below -40°C (-40°F)]) (1 trip detection logic).
  1. Open in engine coolant temperature sensor circuit
  2. Engine coolant temperature sensor
  3. ECM
HINT:
When any of these DTCs is stored, check the engine coolant temperature by entering the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.

Temperature Displayed
Malfunction
-40°C (-40°F)
Open circuit
140°C (284°F) or higher
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 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 below 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.
If the malfunction is not repaired successfully, a DTC is stored 0.5 seconds after the engine is next started.

MONITOR STRATEGY


Frequency of Operation
Continuous

CONFIRMATION DRIVING PATTERN

  1. Turn the ignition switch to ON and wait for 5 seconds or more.

WIRING DIAGRAM


Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.2Tr-Fe Engine Control.Sfi System (W/ Secondary Air Injection System). Dtc P0115 Engine Coolant Temperature Circuit Malfunction


INSPECTION PROCEDURE

HINT:
Read freeze frame data using the intelligent tester. 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.
1.READ VALUE USING INTELLIGENT TESTER (COOLANT TEMP)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the intelligent tester on.

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

  1. Read the value displayed on the intelligent tester.

    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) or higher
    		B
    Between 75 and 100°C (167 and 212°F)
    		C
    HINT:
    1. If there is an open circuit, the intelligent tester indicates -40°C (-40°F).
    1. If there is a short circuit, the intelligent tester indicates 140°C (284°F) or higher.


B
Go to step 4

C
CHECK FOR INTERMITTENT PROBLEMS (HILUX_TGN26 RM000000PDQ0PUX.html)
A


2.READ VALUE USING INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS)
Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.2Tr-Fe Engine Control.Sfi System (W/ Secondary Air Injection System). Dtc P0115 Engine Coolant Temperature Circuit Malfunction

  1. Disconnect the engine coolant temperature sensor connector.

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

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the intelligent tester on.

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

  1. Read the value displayed on the intelligent tester.

    Standard value:
    140°C (284°F) or higher
    Text in Illustration
    *1
    		Engine Coolant Temperature Sensor
    *2
    		ECM
    *a
    		Front view of wire harness connector
    (to Engine Coolant Temperature Sensor)


NG
Go to step 3
OK

CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE ENGINE COOLANT TEMPERATURE SENSOR (HILUX_TGN26 RM000000VWA01HX.html)

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

  1. Disconnect the engine coolant temperature sensor connector.

  1. Disconnect the ECM connector.

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    C17-2 - C75-32 (THW)
    		Always
    		Below 1 Ω
    C17-1 - C75-28 (E2)
    		Always
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

CONFIRM GOOD CONNECTION TO ECM. IF OK, REPLACE ECM (HILUX_TGN26 RM000000VW2023X.html)

4.READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS)
Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.2Tr-Fe Engine Control.Sfi System (W/ Secondary Air Injection System). Dtc P0115 Engine Coolant Temperature Circuit Malfunction

  1. Disconnect the engine coolant temperature sensor connector.

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the intelligent tester on.

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

  1. Read the value displayed on the intelligent tester.

    Standard value:
    -40°C (-40°F)
    Text in Illustration
    *1
    		Engine Coolant Temperature Sensor
    *2
    		ECM


NG
Go to step 5
OK

REPLACE ENGINE COOLANT TEMPERATURE SENSOR (HILUX_TGN26 RM000000VWA01HX.html)

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

  1. Disconnect the engine coolant temperature sensor connector.

  1. Disconnect the ECM connector.

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    C17-2 or C75-32 (THW) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ECM (HILUX_TGN26 RM000000VW2023X.html)