Engine Coolant Temperature Sensor Circuit High Input
The engine computer is getting a coolant temperature reading that is too high or not believable. This usually means the coolant temperature sensor, its wiring, or the connector has a problem. The engine may run poorly until the issue is fixed.
You may be able to drive short distances, but the engine can run too rich, idle poorly, or overheat without warning if the reading is wrong. Have it diagnosed soon.
P0118 means the powertrain control module has detected a high voltage condition in the engine coolant temperature (ECT) sensor circuit. In most systems, high circuit voltage indicates the sensor is reading extremely cold or the circuit is open due to a bad sensor, damaged wiring, or poor connector contact. The PCM uses this signal for fuel control, ignition timing, cooling fan operation, and emissions strategy.
Yes. Low coolant or trapped air can make the sensor read incorrectly and trigger the code.
A bad sensor or an open wiring/connector problem are the most common causes.
Yes, it can. The engine computer may think the engine is colder than it really is and add too much fuel.
You can clear it, but it will likely come back if the fault is still present.