Independent Heater (Option 536)
The independent heating function is activated either via the Central Information Display (CID) or via Telestart (through the Car Access System (CAS)). There are 2 ways of switching the system on via the CID:
Direct operation or programming using the timer.
Conditions required for switching the independent heater on:
- Exterior temperature below 15 °C (only applicable after programming with the timer)
- Sufficient fuel in the vehicles tank for a range of at least 50 km
- On-board supply voltage OK
The independent heater has the following functions:
- Auxiliary heating with running engine (pseudo auxiliary heating)
- Telestart (via CAS)
- Low-voltage cutout
Auxiliary Heating With Running Engine (Pseudo Auxiliary Heating)
When the independent heater is running, pseudo auxiliary heating mode is started when the engine is started. When pseudo auxiliary heating mode is activated, the independent heater indicator lamp goes out.
If the engine temperature is greater than or equal to the temperature of the independent heating circuit, the system will change from pseudo auxiliary heating mode to auxiliary heating. These two modes differ in that only the independent heater circuit is used in pseudo auxiliary heating mode, while in auxiliary heating mode the larger heater circuit is used.
Telestart (via CAS)
The average range of the Telestart transmitter is approx. 150 meters. The CAS forwards the signal from the Telestart transmitter through the body CAN to the following control units:
- IHKA control unit
- Independent heater control unit
Low-Voltage Cutout (via DME/DDE)
The battery's charge level is constantly monitored by the intelligent battery sensor throughout the independent heating operation. If the necessary charge level is not maintained, the IHKA control unit will deactivate the independent heating operation.