P0116: Engine Coolant Temperature Sensor 1 Circuit Range/Performance
What to do
Usually driveable. If the temperature gauge takes a very long time to rise, or never reaches normal, the thermostat is the likely cause rather than the sensor.
What this code means
The coolant temperature reading is electrically valid but behaves implausibly — it warms too slowly, sits at an unlikely value, or disagrees with intake and ambient temperature at key-on after standing overnight. A stuck-open thermostat produces this honestly, by keeping the engine genuinely too cool, so check the thermostat's behaviour before condemning the sensor.
Likely causes
Start here
- Faulty engine coolant temperature sensor · easy
- Thermostat stuck open · moderate
Less common
- Low coolant level · easy
- Air trapped in cooling system · moderate
- Corroded or loose connector · easy
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
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