On a cold engine, the self-ignition temperature is not reached by compression alone, so the engine needs to be preheated.
For this purpose, a glow plug is screwed into each combustion chamber. The candle consists of a body and a pressed heat rod. When voltage is applied, the thermal winding in the core heats up to a temperature of +850°C in a few seconds, due to which the duration of the preheat before starting rarely exceeds 10 seconds. When the preheat indicator lamp on the instrument panel goes out, the engine can be started.
To quickly warm up the engine, the preheater works even after starting the engine. The duration of preheating is regulated by the control device depending on the temperature of the coolant. The control unit is located behind the center console under the air duct.
The preheat control device receives information about the engine temperature from the coolant temperature sensor. Based on the data obtained, the control device determines the duration of the preheat and the magnitude of the current.