Additional heater
The additional heater is standard in cars with diesel engines (certain markets). This function is used for cars in cold markets to provide extra heat to the climate control module. The heater functions in the same way as the parking heater although the start conditions are different. This is controlled by the central electronic module (CEM) (4/56). There is no physical difference between the parking heater and the additional heater. The difference between the functions is in the software.