The Webasto additional heater is an autonomous heating device for the vehicle interior that works either with the ignition switched on (+15) or off; this device makes it possible to:
pre-heat the engine coolant allowing smoother starting and reducing the time it takes for the engine to warm up (especially in particularly harsh climatic conditions);
the heating of the passenger compartment for improved comfort;
the removal of any ice or condensation from the windows.
The system, which basically consists of a heating control unit, an electric fuel metering pump, fuel supply pipes, exhaust pipes and an integrated electric pump for the circulation of the coolant, interfaces with the vehicle cooling, fuel supply and electrical systems: its operation is dependent on the temperature of the engine coolant, the presence of fuel in the tank and commands coming from the climate control system control unit.The Webasto additional heater has three different operating modes:
in Parking Heater mode, with the ignition switched off, a special command (from the timer or remote control) pre-heats the engine coolant and then the passenger compartment in advance of the engine being switched on; the info-telematic control unit can be used to programme the duration of the pre-heating and the time the heater should be switched on and off (timer);
in Rest mode, with the ignition switched off, the thermal energy of the engine coolant is used to heat the passenger comparment (straight after the vehicle is switched off) and thereby maintain the internal temperature;
in Additional Heater mode, with the ignition switched on, the heater comes on when the effective temperature in the passenger compartment is lower than that set by the info-telematic control unit.
Whichever operating mode is set, the device can be switched off using a manual control.The Webasto additional heater control unit manages its own diagnostic signal See E8010 DIAGNOSTIC MULTIPLE CONNECTOR