P0117
1NZ-FXE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0115: Engine Coolant Temperature Circuit
DTC P0115 - Engine Coolant Temperature Circuit
DTC P0117 - Engine Coolant Temperature Circuit Low Input
DTC P0118 - Engine Coolant Temperature Circuit High Input
DESCRIPTION
A thermistor is built in the engine coolant temperature sensor and changes its resistance value according to the engine coolant temperature.
The structure of the sensor and connection to the ECM are the same as those of the intake air temperature sensor.
HINT: If the ECM detects DTC P0115, P0117 or P0118, it operates the fail-safe function in which the engine coolant temperature is assumed to be 80°C (176°F).
HINT: After confirming DTC P0115, P0117 or P0118, confirm the engine coolant temperature from Powertrain / Engine and ECT / Data List / Coolant Temp using Techstream.
MONITOR DESCRIPTION
The engine coolant temperature (ECT) sensor is used to monitor the engine coolant temperature. The ECT sensor has a thermistor that varies its resistance depending on 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. The variations in resistance are reflected in the voltage output 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 ECT sensor and sets a DTC.
Example:
When the ECM calculates that the ECT is -40°C (-40°F), or more than 140°C (284°F), and if either condition continues for 0.5 seconds or more, the ETC will set a DTC.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
P0115:
P0117:
P0118:
COMPONENT OPERATING RANGE
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
- If DTCs related to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.
- Read freeze frame data using 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 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 Freeze Frame Data.
PROCEDURE
1. READ OUTPUT DTC
(a) Connect Techstream to the DLC3.
(b) Turn the power switch ON (IG) and turn Techstream ON.
(c) Enter the following menus: Powertrain / Engine and ECT / Trouble Code.
(d) Read the DTCs.
Result:
C -- READ VALUE USING TECHSTREAM (CHECK FOR OPEN IN WIRE HARNESS)
B -- READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN WIRE HARNESS)
A -- Continue to next step.
2. READ VALUE USING TECHSTREAM (ENGINE COOLANT TEMPERATURE)
(a) Connect Techstream to the DLC3.
(b) Turn the power switch ON (IG).
(c) Turn Techstream ON.
(d) Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
(e) Read the value.
(f) Measure the coolant temperature using a thermometer and compare the value with the value displayed on Techstream.
Temperature value:
Almost same as the actual engine coolant temperature.
Result:
HINT:
- If there is an open circuit, Techstream indicates -40°C (-40°F).
- If there is a short circuit, Techstream indicates 140°C (284°F).
C -- CHECK FOR INTERMITTENT PROBLEMS
B -- READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN WIRE HARNESS)
A -- Continue to next step.
3. READ VALUE USING TECHSTREAM (CHECK FOR OPEN IN WIRE HARNESS)
(a) Disconnect the E1 engine coolant temperature sensor connector.
(b) Connect terminals 1 and 2 of the engine coolant temperature sensor wire harness side connector.
(c) Turn the power switch ON (IG).
(d) Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp. Read the value.
OK:
Temperature value: 140°C (284°F)
(e) Reconnect the engine coolant temperature sensor connector.
OK -- CONFIRM GOOD CONNECTION AT SENSOR. IF OK, REPLACE ENGINE COOLANT TEMP. SENSOR
NG -- Continue to next step.
4. READ VALUE USING TECHSTREAM (CHECK FOR OPEN IN ECM)
(a) Disconnect the E1 engine coolant temperature sensor connector.
(b) Connect terminals THW and E2 of the E4 ECM connector.
HINT: Before checking, do a visual and contact pressure check on the ECM connector.
(c) Turn the power switch ON (IG).
(d) Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp. Read the value.
OK:
Temperature value: 140°C (284°F)
(e) Reconnect the engine coolant temperature sensor connector.
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR
NG -- CONFIRM GOOD CONNECTION AT ECM. IF OK, REPLACE ECM
5. READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN WIRE HARNESS)
(a) Disconnect the E1 engine coolant temperature sensor connector.
(b) Turn the power switch ON (IG).
(c) Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
(d) Read the value.
OK:
Temperature value: -40°C (-40°F)
(e) Reconnect the engine coolant temperature sensor connector.
OK -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR
NG -- Continue to next step.
6. READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN ECM)
(a) Disconnect the E4 ECM connector.
(b) Turn the power switch ON (IG).
(c) Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
(d) Read the value.
OK:
Temperature value: -40°C (-40°F)
(e) Reconnect the ECM connector.
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR
NG -- REPLACE ECM