192004631 - E6015 ADDITIONAL HEATER - DESCRIPTION
Description
The climate control via the heater unit is insufficient when the engine is cold, especially in Diesel engines which are slow to warm up.These engines may optionally be fitted with a supplementary heater system. This remains active from the moment when the engine is turned on until a certain temperature is reached.The system consists of an additional heater, located in the heater unit: the device contains three resistances (PTC).The operation of the resistances is controlled by a specific control unit - connected via the CAN network to the car''s other nodes - which drives only one, or two or three, thus providing progressive heating.This control logic depends on:
- the temperature of the engine coolant;
- the electrical power available (in effect, the battery voltage is checked)
- the engine speed (which should be above a pre-set value).
The supply of one, two or three resistances is controlled by two relays located on the heater unit:
- 1. Level: activated by the first relay;
- 2. Level: activated by the second relay;
- 3. Level: activated by both relays.