P0116
1GR-FE 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 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 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.
- When any of these DTCs are set, check the ECT by entering the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.
MONITOR DESCRIPTION
Engine coolant temperature (ECT) sensor cold start monitor
The monitor runs when the engine is started cold. If the change in engine coolant temperature sensor output until the engine warmed up completely is less than the threshold, it is determined that a malfunction has occurred in the engine coolant temperature sensor. When this is detected in 2 consecutive driving cycles, the MIL is illuminated and the DTC is set.
ECT sensor soak monitor
The ECM compares the engine coolant temperature when the warmed engine is stopped and when the engine is started on the next trip when more than 5 hours has elapsed since the engine was stopped. If the change in engine coolant temperature sensor output is less than the threshold, it is determined that a malfunction has occurred in the engine coolant temperature sensor. When this is detected in 2 consecutive driving cycles, the MIL is illuminated and the DTC is set.
ECT sensor high side stuck monitor (only for Mexico models)
The ECM monitors the sensor voltage and uses this value to calculate the ECT. If the sensor voltage output deviates from the normal operating range, the ECM interprets this deviation as a malfunction in the ECT sensor and sets the DTC.
Examples:
- Upon starting the engine, the ECT is between 35°C and 60°C (95°F and 140°F). If after driving for 250 seconds, the ECT remains within 3°C (5.4°F) of the starting temperature, the DTC is set (2 trip detection logic).
- Upon starting the engine, the ECT is over 60°C (140°F). If after driving for 250 seconds, the ECM remains within 1°C (1.8°F) of the starting temperature, the DTC is set (6 trip detection logic).
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 record 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 a Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(e) Read the DTC.
Result
B -- GO TO DTC CHART
A -- Continue to next step.
2. INSPECT W/THERMOSTAT WATER INLET SUB-ASSEMBLY (THERMOSTAT)
(a) Remove the w/thermostat water inlet sub-assembly 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 w/thermostat water inlet sub-assembly Installation.
NG -- REPLACE W/THERMOSTAT WATER INLET SUB-ASSEMBLY
OK -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR