P0116 Code: Engine Coolant Temperature (ECT) Sensor Range / Performance
P0116 means the coolant temperature sensor’s reading is implausible or doesn’t change as expected.
- Applies to
- All OBD-II vehicles (any make or model)
- Est. repair cost
- $30 – $250
- Time to fix
- 1-3 hours
What it means
Common causes are a failing ECT sensor, low coolant, or a stuck thermostat. This is a generic OBD-II powertrain code defined in the SAE J2012 standard, so it applies to virtually any 1996-or-newer OBD-II vehicle — cars, trucks, and modern fuel-injected motorcycles — from any manufacturer (Toyota, Honda, Ford and the rest). Read it with any OBD-II scanner; the meaning is the same across brands, though the exact repair can vary by engine.
Symptoms
- Check engine light on
- Poor cold-start running or fan behaving oddly
- Fuel economy affected
How to fix it
- 1
Check coolant and the ECT sensor
1. Confirm the coolant level and that the thermostat opens. 2. Test the ECT sensor resistance vs temperature. 3. Replace a faulty sensor or thermostat, then clear the code.
Frequently asked questions
Can a thermostat cause P0116?
Yes — a thermostat stuck open makes the engine warm up too slowly, so the ECT reading looks wrong. Check the thermostat and coolant along with the sensor.
Last updated July 16, 2026
Guidance only — always consult a qualified professional or the official service manual before carrying out repairs.