Dtc P0115 Engine Coolant Temperature Circuit Malfunction

Engine Hybrid System. Land Cruiser. Urj200, 202 Grj200 Vdj200
3Ur-Fe Engine Control. Land Cruiser. Urj200, 202 Grj200 Vdj200

DESCRIPTION

MONITOR DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING GTS (ENGINE COOLANT TEMPERATURE)

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

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

READ VALUE USING GTS (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 ECT, is built into the Engine Coolant Temperature (ECT) sensor.
The structure of the sensor and its connection to the ECM are the same as those of the Intake Air Temperature (IAT) sensor.
HINT:
When any of DTCs P0115, P0117 and P0118 is stored, the ECM enters fail-safe mode. During fail-safe mode, the ECT is estimated to be 80°C (176°F) by the ECM. Fail-safe mode continues until a pass condition is detected.

DTC Code
DTC Detection Condition
Trouble Area
P0115
An open or short in the Engine Coolant Temperature (ECT) sensor circuit for 0.5 seconds (1 trip detection logic).
  1. Open or short in Engine Coolant Temperature (ECT) sensor circuit
  2. ECT sensor
  3. ECM
P0117
A short in the ECT sensor circuit for 0.5 seconds (1 trip detection logic).
  1. Short in ECT sensor
  2. ECT sensor
  3. ECM
P0118
An open in the ECT sensor circuit for 0.5 seconds (1 trip detection logic).
  1. Open in ECT sensor circuit
  2. ECT sensor
  3. ECM
HINT:
When any of these DTCs is output, check the ECT 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 (ECT) sensor is used to monitor the ECT. The ECT 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 ECT. When the sensor output voltage deviates from the normal operating range, the ECM interprets this as a fault in the ECT sensor and stores DTC(s).
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 ECT 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.

WIRING DIAGRAM


Land Cruiser. Urj200, 202 Grj200 Vdj200.3Ur-Fe Engine Control.Sfi System. Dtc P0115 Engine Coolant Temperature Circuit Malfunction


INSPECTION PROCEDURE

HINT:
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.
1.READ VALUE USING GTS (ENGINE COOLANT TEMPERATURE)

  1. Connect the GTS to the DLC3.

  1. Turn the engine switch on (IG).

  1. Turn the tester on.

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

  1. Read the value displayed on the tester.

    Standard value:
    Between 75 and 100°C (167 and 212°F) with warm engine.

    Result
    Temperature Displayed
    		Proceed to
    -40°C (-40°F)
    		A
    140°C (284°F) or higher
    		B
    Between 75 and 100°C (176 and 212°F)
    		C
    HINT:
    1. If there is an open circuit, the tester indicates -40°C (-40°F).
    2. If there is a short circuit, the tester indicates 140°C (284°F) or higher.


B
Go to step 4

C
CHECK FOR INTERMITTENT PROBLEMS (Click here)
A


2.READ VALUE USING GTS (CHECK FOR OPEN IN WIRE HARNESS)
Land Cruiser. Urj200, 202 Grj200 Vdj200.3Ur-Fe Engine Control.Sfi System. Dtc P0115 Engine Coolant Temperature Circuit Malfunction

  1. Disconnect the C18 Engine Coolant Temperature (ECT) sensor connector.

  1. Connect terminals 1 and 2 of the ECT sensor connector on the wire harness side.

  1. Connect the GTS to the DLC3.

  1. Turn the engine switch on (IG).

  1. Turn the tester on.

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

  1. Read the value displayed on the tester.

    Standard value:
    140°C (284°F) or higher


NG
Go to step 3
OK

GOOD CONNECTION TO ECM. IF OK, REPLACE ECM (Click here)

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

  1. Disconnect the C18 ECT sensor connector.

  1. Disconnect the C45 ECM connector.

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    C18-2 - C45-76 (THW)
    		Always
    		Below 1 Ω
    C18-1 - C45-97 (ETHW)
    		Always
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE ENGINE COOLANT TEMPERATURE SENSOR (Click here)

4.READ VALUE USING GTS (CHECK FOR SHORT IN WIRE HARNESS)
Land Cruiser. Urj200, 202 Grj200 Vdj200.3Ur-Fe Engine Control.Sfi System. Dtc P0115 Engine Coolant Temperature Circuit Malfunction

  1. Disconnect the C18 ECT sensor connector.

  1. Connect the GTS to the DLC3.

  1. Turn the engine switch on (IG).

  1. Turn the tester on.

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

  1. Read the value displayed on the tester.

    Standard value:
    -40°C (-40°F)


NG
Go to step 5
OK

REPLACE ENGINE COOLANT TEMPERATURE SENSOR (Click here)

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

  1. Disconnect the C18 ECT sensor connector.

  1. Disconnect the C45 ECM connector.

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    C18-2 or C45-76 (THW) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ECM (Click here)