What does P0116 mean?
The engine coolant temperature (ECT) sensor tells the computer how hot the engine is. It affects fuel mixture, idle speed, cooling fans and, on many cars, the temperature gauge.
The temperature reading does not make sense compared with other sensors or with how long the engine has been running.
Codes are a starting point. They tell you which test failed, not which part to replace. Check for other stored codes and fix those in a sensible order.
Symptoms
- Check engine light
- Hard starting
- Cooling fans running all the time (a common fail-safe)
- Poor fuel economy
- Wrong temperature gauge reading on some vehicles
Common causes
- Sensor skewed out of calibration
- Real temperature problem (for example a stuck thermostat)
- Poor connection adding resistance
- Failed ECT sensor
- Damaged connector or wiring
- Low coolant leaving the sensor in air
How to diagnose P0116
- After a cold soak overnight, compare this sensor with the other temperature sensors. They should all read within a few degrees.
- Check that the actual temperature matches with an infrared thermometer.
- Inspect the connector for corrosion.
- Check the coolant level first (only when the engine is cold).
- Compare ECT with intake air temperature after an overnight cold soak.
How to fix it
- Top up or bleed the cooling system
- Repair wiring
- Replace the ECT sensor
Estimated repair cost
Likely repairs for P0116 run from about $80 to $250, depending on the cause.
| Repair | Typical range (parts + labor) |
|---|---|
| Diagnostic fee (scan + testing) | $100 - $200 |
| Coolant temperature sensor | $80 - $250 |
These are rough US estimates for an independent shop in 2026, based on typical parts prices and standard labor times. Dealers, big trucks, luxury brands and high-cost areas often run higher. They are not quotes. Use the repair cost estimator to adjust for your vehicle.
How serious is P0116?
Moderate severity
Usually drivable, but keep an eye on the real engine temperature. If it is overheating, stop.
P0116 FAQ
What does P0116 mean?
P0116 stands for "Engine Coolant Temperature Sensor 1 Circuit Range/Performance". The engine coolant temperature (ECT) sensor tells the computer how hot the engine is.
Can I drive with a P0116 code?
Usually drivable, but keep an eye on the real engine temperature. If it is overheating, stop.
How much does it cost to fix P0116?
It depends on the cause. The likely repairs for P0116 range from about $80 to $250 at an independent shop in the US, plus a diagnostic fee of roughly $100-$200. These are rough estimates; dealer prices and some vehicles run higher.
What is the most common cause of P0116?
The most common causes are: sensor skewed out of calibration; real temperature problem (for example a stuck thermostat); poor connection adding resistance.