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ENRUDEPLES

P0118 — Engine Coolant Temperature Circuit High Input

moderate

What it means

The sensor voltage stays above the permitted limit, which the control module reads as an extremely cold engine. It therefore holds cold start enrichment permanently and may not switch on the radiator fans. Typical results are black smoke, very high fuel consumption, fouled spark plugs and a real risk of overheating in traffic.

Likely causes (most common first)

  1. Open circuit in the sensor signal or ground wire
  2. Loose, corroded or disconnected sensor connector
  3. Faulty coolant temperature sensor with an internal open circuit
  4. Low coolant level so the sensor is surrounded by air
  5. Short to voltage in the signal wire
  6. Faulty engine control module (rare)

Can you drive with it?

Drive only to the nearest workshop and avoid standing traffic: the fans may stay off and the engine can overheat.

This is the generic meaning. What about your car?

The same code has different typical culprits on different engines. Tell the AI your make, model and year — it will rank the causes for your exact car and give you a check order.

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