P0116

1UR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0116: Engine Coolant Temperature Circuit Range / Performance Problem

DTC P0116 - Engine Coolant Temperature Circuit Range / Performance Problem

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 DTC P0115, P0117 or P0118 is set, 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.





HINT: When any of these DTCs are set, check the ECT by entering the following menus: Powertrain / Engine / Data List / All Data / Coolant Temp.










MONITOR DESCRIPTION

ECT sensor cold start monitor

When a cold engine start is performed and then the engine is warmed up, if the ECT sensor value does not change, it is determined that a malfunction has occurred. If this is detected in 2 consecutive driving cycles, the MIL is illuminated and a DTC is set.

ECT sensor soak monitor

If the ECT sensor value does not change after the warmed up engine is stopped and then the next cold engine start is performed, it is determined that a malfunction has occurred. If this is detected in 2 consecutive driving cycles, the MIL is illuminated and a DTC is set.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

ECT Sensor cold start monitor:





ECT Sensor soak monitor:





TYPICAL MALFUNCTION THRESHOLDS

ECT Sensor cold start monitor:





ECT Sensor soak monitor:





COMPONENT OPERATING RANGE





INSPECTION PROCEDURE
HINT:
- If any of DTCs P0115, P0117, P0118 or P0125 are set simultaneously with DTC P0116, the ECT sensor may have an open or a short circuit. Troubleshoot those DTCs first.
- Read freeze frame data using the Techstream. 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.

PROCEDURE

1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0116)
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream ON.
(d) Enter the following menus: Powertrain / Engine / Trouble Codes.
(e) Read the DTC.
Result:






B -- GO TO DTC CHART SFI System
A -- Continue to next step.

2. INSPECT WATER INLET WITH THERMOSTAT
(a) Remove the water inlet with thermostat Removal.
(b) Check the valve opening temperature of the thermostat.
Standard:
80°C to 84°C (176°F to 183°F)
HINT:
In addition to the above check, confirm that the valve is completely closed when the temperature is below the standard.
(c) Reinstall the water inlet with thermostat Installation.
NG -- REPLACE WATER INLET WITH THERMOSTAT
OK -- REPLACE ENGINE COOLANT TEMPERATURE