What are the common causes of P0116?

Stuck-open or stuck-closed thermostat. Faulty or slow coolant temperature sensor. Low coolant level or air in the system. Sensor reading implausibly for warm-up conditions.

Note the ECT rise during warm-up with a scan tool. Check coolant level and thermostat operation. Test the sensor's resistance and calibration. Replace the thermostat if the engine fails to reach temperature. Replace the sensor if readings are erratic.

P0116

Engine Coolant Temperature Sensor 1 Circuit Range/Performance

System: Fuel and air metering (P code)
Lamp: Check Engine Light
Category: Powertrain - Fuel/Air Metering

What it means

P0116 means Engine Coolant Temperature Sensor 1 Circuit Range/Performance.

Where it lives

For P0116, the part to look at first is the sensor named here.

Check these first

Stuck-open or stuck-closed thermostat
Faulty or slow coolant temperature sensor
Low coolant level or air in the system
Sensor reading implausibly for warm-up conditions

What to do next

Note the ECT rise during warm-up with a scan tool
Check coolant level and thermostat operation
Test the sensor's resistance and calibration
Replace the thermostat if the engine fails to reach temperature
Replace the sensor if readings are erratic

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Updated

Generic SAE J2012 definition. Last updated 2026-08-30.