P0116

DTC P0116 Engine Coolant Temperature Circuit Range/Performance Problem

DESCRIPTION

DTC Detection Condition:

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 connection to the ECM is the same as 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.

HINT: When any of these DTCs are set, check the ECT by selecting the following menu items on an intelligent tester: DIAGNOSIS/ENHANCED OBD II/DATA LIST/PRIMARY/COOLANT TEMP.

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Conditions (Part 1):

Typical Enabling Conditions (Part 2):

Typical Malfunction Thresholds:

Component Operating Range:

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
After a warmed up engine is started, if the ECT sensor value does not change when the 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.

Wiring Diagram:

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 intelligent tester. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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.