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 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. 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.
PROCEDURE
1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0116)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch on.
(c) Turn the tester 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 WATER INLET WITH THERMOSTAT
(a) Remove the water inlet with thermostat.
(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.
NG -- REPLACE WATER INLET WITH THERMOSTAT
OK -- REPLACE COOLANT TEMPERATURE SENSOR