Seat heating, rear left and right

The seat heating system heats the seat cushion area and the backrest.

Brief description of components

Button with function indicator

The seat heating is switched on and off using a button. The activated function is indicated by an integrated light emitting diode.

The electronics for the seat heating are integrated in the switch block.

Temperature control

The temperature setting can be adjusted by means of a potentiometer within the range from 20°C to 42°C.

Heating elements

The seat heating elements are designed as resistor pads. A heating element is fitted in each seat cushion and each backrest.

Temperature sensor

The temperature is determined by a temperature sensor in the seat upholstery.

Main functions

Activation

The seat heating can be switched on as of terminal 15 by pressing the button. The activated function is indicated by an integrated light emitting diode lighting up.

Deactivation

The switched on seat heating can be switched off by pressing the button. On switching off, the light emitting diode goes out. When the ignition is switched off, the seat heating and light emitting diode are also switched off.

Temperature control

The seat heating electronics integrated in the button regulate the flow of current to the heating elements. The temperature set using the potentiometer is reached in the fastest possible time. The seats are heated by means of heating elements incorporated in the upholstery of the seat surface and in the backrest. The current temperature is determined by a temperature sensor at the heating element in the seat upholstery. The value determined is transferred to the electronics for the seat heating. Once the temperature set using the potentiometer is reached, the electronics reduce the heat output.

Undervoltage cutout

At a battery voltage < 11.8 V, the electronics switch the seat heating off. The light emitting diode in the button remains on. At a battery voltage > 11.8 V, the electronics switch the seat heating on again.

Operation monitoring and fault display

The electronics integrated in the button monitor the temperature sensor and the heating elements (resistor pads) in the seat. If a break or short circuit occurs at the temperature sensor, the seat heating is switched off in order to prevent overheating.

Fault display

The light emitting diode in the button flashes