Coolant temperature gauge (BMW X3 E83)

Blue sector

The engine is still cold. Engine speed and driving speed should be moderate.

Between the colored sectors

Normal operating temperature. The arrow can reach up to the red sector.

Red sector

The light came on while driving - the engine overheated. Stop driving, turn off the engine and let it cool down. When the ignition is turned on, the indicator lamp 1 is checked: it lights up for a while.