The front and rear seats are equipped with a special heater system (comprising two heating elements located in the cushion and backrest): this allows the seat to be heated to overcome the discomfort of cold passenger compartments in very harsh climates, e.g. when the car is left in the open for long periods in winter.The seat heating device can be activated only under conditions of key-on (+15). Its operating strategy is as follows:
when the heat pad activation control (located on the seat control unit for front seats and the armrest for rear seats) is moved to one of the three possible positions, the seat control units (with the exception of driver''s seat control unit NAG) download a signal that is forwarded to the boot control unit;
this feedback signal is managed by the control unit, which excites the coil of the service relay located in the boot junction unit via a positive signal;
the relay thus allows a power supply to reach the heat pads via two lines protected by fuses. The power supply is in all cases controlled by the relevant seat control units.
Activation of the front seat heat pads is indicated by a message on the infotelematic control unit display. The control unit downloads this information (sent via the CAN network) from the boot control unit (via feedback signals from the seat control units).Once a certain temperature has been reached, a sensor inside the heat pads on the front and rear cushions allows the device to be deactivated. The infotelematic control unit must still display a message showing that the heat pads are active during the deactivation period.he device is excluded temporarily during start-up (INT/A).