For 1990-2009 cars

The gage shows the engine coolant temperature. If the pointer moves into the red area, your coolant is about 246°F (119°C) or more, your engine is too hot! That reading means the same thing as a warning light.

It means that your engine coolant has overheated and you should stop your vehicle, turn the air conditioning off, and let the engine idle for a few minutes. Then, turn off the engine.

During extremely cold weather, 10°F (-12°C) or colder, your engine's coolant temperature will decrease quickly when idling with the heater fan on high speed and cool air may flow in from the heater outlets. The fan control switch can be set at a slower speed position (fan speed I or II) to maintain the hottest air flow.

If your engine control system detects a failure in the engine coolant temperature circuit, the "Service Engine Soon" light will come on. The coolant gage may read all the way hot or cold. The engine cooling fan will be turned on to protect the engine and transaxle.