P0116

DTC P0116 Engine Coolant Temperature Circuit Range/Performance Problem

CIRCUIT DESCRIPTION

DTC Detecting Condition:

A thermistor is built into the engine coolant temperature sensor, and its resistance value varies according to the engine coolant temperature.

The structure of the sensor and its connection to the ECM are the same as those of the intake air temperature sensor.

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Conditions:

Typical Malfunction Thresholds:

Component Operating Range:

The engine coolant temperature (ECT) sensor is used to monitor the engine coolant temperature. 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 of the thermistor increases. When the temperature is high, the resistance drops. These variations in the 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. If the sensor output voltage deviates from the normal operating range, the ECM interprets this deviation as a fault in the ECT sensor and sets the DTC.

Examples:
1. Upon starting the engine, the coolant temperature (ECT) is between 35 °C (95 °F) and 60 °C (140 °F). If after driving for 250 seconds, the ECT remains within 3 °C (5.4 °F) of the staring temperature, the DTC is set (2 trip detection logic).
2. Upon starting the engine, the coolant temperature (ECT) is over 60 °C (140 °F). If after driving for 250 seconds, the ECT remains within 1 °C (1.8 °F) of the starting temperature, the DTC is set (6 trip detection logic).

INSPECTION PROCEDURE

HINT:
- If any of DTCs P0115, P0116, P0117, P0118 and P0125 are output simultaneously, the engine coolant temperature sensor circuit may be open or short. Perform troubleshooting of DTC P0115, P0117 or P0118 first.
- Read freeze frame data using the hand-held tester or the OBD II scan tool. 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.

Replace engine coolant temperature sensor.