Dtc P0115 Engine Coolant Temperature Circuit Malfunction

Engine Hybrid System. Yaris. Ncp93, 131
1Nz-Fe Engine Control. Yaris. Ncp93, 131

DESCRIPTION

MONITOR DESCRIPTION

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

COMPONENT OPERATING RANGE

CONFIRMATION DRIVING PATTERN

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING TECHSTREAM (ENGINE COOLANT TEMPERATURE)

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

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

READ VALUE USING TECHSTREAM (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 is built into the Engine Coolant Temperature (ECT) sensor, of which the resistance value varies according to the ECT.
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 No.
DTC Detection Condition
Trouble Area
P0115
Open or short in ECT sensor circuit for 0.5 seconds (1 trip detection logic)
  1. Open or short in ECT sensor circuit
  2. ECT sensor
  3. ECM
P0117
Short in ECT sensor circuit for 0.5 seconds (1 trip detection logic)
  1. Short in ECT sensor circuit
  2. ECT sensor
  3. ECM
P0118
Open in 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 on the Techstream: Powertrain / Engine and ECT / Data List / Coolant Temp.

Temperature Displayed
Malfunction
-40°C (-40°F)
Open circuit
135°C (275°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 more 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 less than 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


Related DTCs
P0115: ECT sensor range check (Fluctuating)
P0117: ECT sensor range check (Low voltage)
P0118: ECT sensor range check (High voltage)
Required Sensors/Components (Main)
ECT sensor
Required Sensors/Components (Related)
-
Frequency of Operation
Continuous
Duration
0.5 seconds
MIL Operation
Immediate
Sequence of Operation
None

TYPICAL ENABLING CONDITIONS


Monitor runs whenever following DTCs not present
None

TYPICAL MALFUNCTION THRESHOLDS


P0115:
ECT sensor voltage
Less than 0.14 V [More than 135°C (275°F)], or more than 4.91 V [Less than -60°C (-76°F)]

P0117:
ECT sensor voltage [ECT]
Less than 0.14 V [More than 135°C (275°F)]

P0118:
ECT sensor voltage [ECT]
More than 4.91 V [Less than -60°C (-76°F)]

COMPONENT OPERATING RANGE


ECT sensor voltage [ECT]
0.14 to 4.91 V [-60°C to 135°C (-76°F to 275°F)]

CONFIRMATION DRIVING PATTERN

  1. Connect the Techstream to the DLC3.
  2. Turn the ignition switch to ON and turn the Techstream on.
  3. Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).
  4. Turn the ignition switch off and wait for at least 30 seconds.
  5. Turn the ignition switch to ON and turn the Techstream on.
  6. Wait 0.5 seconds or more.
  7. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
  8. Read pending DTCs.
    HINT:
    1. If a pending DTC is output, the system is malfunctioning.
    2. If a pending DTC is not output, perform the following procedure.
  9. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
  10. Input the DTC: P0115, P0117 or P0118.
  11. Check the DTC judgment result.

    Techstream Display
    Description
    NORMAL
    1. DTC judgment completed
    2. System normal
    ABNORMAL
    1. DTC judgment completed
    2. System abnormal
    INCOMPLETE
    1. DTC judgment not completed
    2. Perform driving pattern after confirming DTC enabling conditions
    N/A
    1. Unable to perform DTC judgment
    2. Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit
    HINT:
    1. If the judgment result shows NORMAL, the system is normal.
    2. If the judgment result shows ABNORMAL, the system has a malfunction.
  12. If the test result is INCOMPLETE or N/A and no pending DTC is output, perform a universal trip and check for permanent DTCs (YARIS_NCP93 RM000000PDK0QGX.html).
    HINT:
    1. If a permanent DTC is output, the system is malfunctioning.
    2. If no permanent DTC is output, the system is normal.

WIRING DIAGRAM


Yaris. Ncp93, 131.1Nz-Fe Engine Control.Sfi System (For Sedan).
Dtc
  P0115  Engine Coolant Temperature Circuit Malfunction


INSPECTION PROCEDURE

HINT:
  1. Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. 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.
  2. If DTC P0117 is stored, check that the engine does not overheat (the DTC P0117 may be stored due to engine overheating).
1.READ VALUE USING TECHSTREAM (ENGINE COOLANT TEMPERATURE)
  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

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

  1. Read the value displayed on the Techstream.

    Standard Value:
    80°C to 100°C (167°F to 212°F) with warm engine.

    Result
    Temperature Displayed
    Proceed To
    -40°C (-40°F)
    A
    135°C (275°F) or higher
    B
    80°C to 100°C (167°F to 212°F)
    C
    HINT:
    1. If there is an open circuit, the Techstream indicates -40°C (-40°F).
    2. If there is a short circuit, the Techstream indicates 135°C (275°F) or higher.


B
Go to step 4

C
CHECK FOR INTERMITTENT PROBLEMS (YARIS_NCP93 RM000000PDQ0NOX.html)
A


2.READ VALUE USING TECHSTREAM (CHECK FOR OPEN IN WIRE HARNESS)
Yaris. Ncp93, 131.1Nz-Fe Engine Control.Sfi System (For Sedan).
Dtc
  P0115  Engine Coolant Temperature Circuit Malfunction
  1. Disconnect the C19 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 Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

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

  1. Read the value displayed on the Techstream.

    Standard Value:
    135°C (275°F) or higher.
  1. Reconnect the ECT sensor connector.



NG
Go to step 3
OK

CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE ENGINE COOLANT TEMPERATURE SENSOR (YARIS_NCP93 RM000001DBH011X.html)

3.CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)
Yaris. Ncp93, 131.1Nz-Fe Engine Control.Sfi System (For Sedan).
Dtc
  P0115  Engine Coolant Temperature Circuit Malfunction
  1. Disconnect the C19 ECT sensor connector.

  1. Disconnect the C20 ECM connector.

  1. Check the resistance.

    Standard resistance:
    Tester Connections
    Specified Conditions
    THW (C19-2) - THW (C20-97)
    Below 1 Ω
    E2 (C19-1) - ETHW (C20-96)
  1. Reconnect the ECT sensor connector.

  1. Reconnect the ECM connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

GOOD CONNECTION TO ECM. IF OK, REPLACE ECM (YARIS_NCP93 RM000001CN002AX.html)

4.READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN WIRE HARNESS)
Yaris. Ncp93, 131.1Nz-Fe Engine Control.Sfi System (For Sedan).
Dtc
  P0115  Engine Coolant Temperature Circuit Malfunction
  1. Disconnect the C19 ECT sensor connector.

  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

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

  1. Read the value displayed on the Techstream.

    Standard Value:
    -40°C (-40°F)
  1. Reconnect the ECT sensor connector.



NG
Go to step 5
OK

REPLACE ENGINE COOLANT TEMPERATURE SENSOR (YARIS_NCP93 RM000001DBH011X.html)

5.CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)
Yaris. Ncp93, 131.1Nz-Fe Engine Control.Sfi System (For Sedan).
Dtc
  P0115  Engine Coolant Temperature Circuit Malfunction
  1. Disconnect the C19 ECT sensor connector.

  1. Disconnect the C20 ECM connector.

  1. Check the resistance.

    Standard resistance:
    Tester Connections
    Specified Conditions
    THW (C19-2) or THW (C20-97) - Body ground
    10 kΩ or higher
  1. Reconnect the ECT sensor connector.

  1. Reconnect the ECM connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ECM (YARIS_NCP93 RM000001CN002AX.html)