P0116 — Engine Coolant Temperature Sensor Range/Performance
Moderate severityWhat it means
P0116 is stored when the engine control unit sees a fault involving the engine coolant temperature (ECT) sensor signal. The ECT sensor reports engine temperature, which drives cold-start enrichment, the cooling fan and the temperature gauge. A “range/performance” fault means the value is present but implausible — it does not agree with other sensors or expected conditions.
Common symptoms
- Readings that drift or disagree with related sensors
- Hard cold starts or rough warm-up
- Cooling fan running constantly or not at all
- Poor fuel economy
Likely causes
- Drifting, contaminated or aged sensor
- A mechanical issue skewing the reading
- Faulty ECT sensor
- Low coolant or a wiring/connector fault
What to check first
- Cross-check the reading against related sensors in live data on a cold start
- Watch the coolant temperature climb from cold to about 90°C in live data
- Compare ECT and IAT on a cold engine — they should match
Can you keep driving?
Often drivable, but wrong temperature data wastes fuel and can cause overheating or fan problems — fix it soon.
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