DTC P0115 DTC P0117 DTC P0118 2ZR-FXE

DTC P0115 Engine Coolant Temperature Circuit Malfunction

DTC P0117 Engine Coolant Temperature Circuit Low Input

DTC P0118 Engine Coolant Temperature Circuit High Input

  1. Description

  2. Monitor description

  3. Monitor strategy

  4. Confirmation driving pattern

  5. Wiring diagram

  6. Inspection procedure

  7. Read value using intelligent tester (engine coolant temperature)

  8. Read value using intelligent tester (check for open in wire harness)

  9. Check harness and connector (engine coolant temperature sensor - ecm)

  10. Read value using intelligent tester (check for short in wire harness)

  11. Check harness and connector (engine coolant temperature sensor - ecm)

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 any of DTCs P0115, P0117 and P0118 are set, 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 Open or short in engine coolant temperature sensor circuit for 0.5 seconds (1 trip detection logic).
  1. Open or short in engine coolant temperature sensor circuit
  2. Engine coolant temperature sensor
  3. ECM
P0117 Short in engine coolant temperature sensor circuit for 0.5 seconds (1 trip detection logic).
  1. Short in engine coolant temperature sensor circuit
  2. Engine coolant temperature sensor
  3. ECM
P0118 Open in engine coolant temperature sensor circuit for 0.5 seconds (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 are set, check the engine coolant temperature by entering the following menus: Powertrain / Engine and ECT / Data List / 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 becomes low, the resistance in the thermistor increases. When the temperature becomes 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 sets a DTC.

Monitor strategy

Frequency of Operation Continuous

Confirmation driving pattern

  1. Turn the power switch on (IG) and wait for 0.5 seconds or more.

Wiring diagram

Lexus DTC P0115 DTC P0117 DTC P0118 Wiring diagram

Inspection procedure

HINT:

Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

1.READ VALUE USING INTELLIGENT TESTER (ENGINE COOLANT TEMPERATURE)
  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  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:

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

    Result
    Result Proceed to
    -40°C (-40°F) A
    140°C (284°F) B
    Between 75°C and 100°C (167°F and 212°F) C

    HINT:

    1. If there is an open circuit, the tester indicates -40°C (-40°F).
    1. If there is a short circuit, the tester indicates 140°C (284°F).
  B  
Go to step 4
 
  C  
CHECK FOR INTERMITTENT PROBLEMS
 
OK  
   

2.READ VALUE USING INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS)
  1. Disconnect the engine coolant temperature sensor connector.

    Lexus DTC  P0115 DTC  P0117 DTC  P0118 Disconnect the engine coolant temperature sensor connector.
    Text in Illustration
    *1 Engine Coolant Temperature Sensor *2 ECM
    *a Front view of wire harness connector (to Engine Coolant Temperature Sensor) - -
  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 power switch on (IG).

  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)

  NG  
Go to step 3
 
OK  
   
REPLACE ENGINE COOLANT TEMPERATURE SENSOR

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
    D6-2 - D27-64 (THW) Always Below 1 ?
    D6-1 - D27-65 (ETHW) Always Below 1 ?
  NG  
REPAIR OR REPLACE HARNESS OR CONNECTOR
 
OK  
   
REPLACE ECM

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

Lexus DTC  P0115 DTC  P0117 DTC  P0118 Disconnect the engine coolant temperature sensor connector.

  1. Disconnect the engine coolant temperature sensor connector.

    Text in Illustration
    *1 Engine Coolant Temperature Sensor
    *2 ECM
  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  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)
  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
    D6-2 or D27-64 (THW) - Body ground Always 10 k? or higher
  NG  
REPAIR OR REPLACE HARNESS OR CONNECTOR
 
OK  
   
REPLACE ECM