DTC P0115 P0117 P0118 1GR-FE

DESCRIPTION

MONITOR DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING INTELLIGENT TESTER (ENGINE COOLANT TEMPERATURE)

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 DTC P0115

A thermistor, whose resistance value varies according to the Engine Coolant Temperature (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 are 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 are output, check the ECT by entering the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.

Tester Display 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 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 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

DTC P0115 Wiring diagram. Land Cruiser 1GR-FE.

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 (ENGINE COOLANT TEMPERATURE)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the tester on.

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

  1. Read the value displayed on the tester.

    Result
    Result Proceed to
    -40°C (-40°F) A
    140°C (284°F) or higher B
    Between 80°C and 100°C (176°F and 212°F) with warm engine 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
 
A  
   

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

DTC P0115 Disconnect the Engine Coolant Temperature (ECT) sensor connector. Land Cruiser 1GR-FE.

  1. Disconnect the 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 intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the tester on.

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

  1. Read the value displayed on the tester.

    Standard value:

    140°C (284°F) or higher.

  NG  
Go to step 3
 
OK  
   
CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE ENGINE COOLANT TEMPERATURE SENSOR

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

DTC P0115 Disconnect the ECM connector. Land Cruiser 1GR-FE.

  1. Disconnect the ECM connector.

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

    Standard Resistance:

    for LHD
    Tester Connection Condition Specified Condition
    C18-2 - C45-79 (THW) Always Below 1 ?
    C18-1 - C45-78 (ETHW) Always Below 1 ?
    for RHD
    Tester Connection Condition Specified Condition
    C18-2 - C46-79 (THW) Always Below 1 ?
    C18-1 - C46-78 (ETHW) Always Below 1 ?
  NG  
REPAIR OR REPLACE HARNESS OR CONNECTOR
 
OK  
   
CONFIRM GOOD CONNECTION TO ECM. IF OK, REPLACE ECM

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

DTC P0115 Disconnect the ECT sensor connector. Land Cruiser 1GR-FE.

  1. Disconnect the ECT sensor connector.

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the tester on.

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

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

DTC P0115 Land Cruiser 1GR-FE.

  1. Disconnect the ECM connector.

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

    Standard Resistance:

    for LHD
    Tester Connection Condition Specified Condition
    C18-2 or C45-79 (THW) - Body ground Always 10 k? or higher
    for RHD
    Tester Connection Condition Specified Condition
    C18-2 or C46-79 (THW) - Body ground Always 10 k? or higher
  NG  
REPAIR OR REPLACE HARNESS OR CONNECTOR
 
OK  
   
REPLACE ECM