GF91.30-P-0002RI Electric Seat Ventilation, Function

GF91.30-P-0002RI Electric Seat Ventilation, Function
- with CODE (401) Front deluxe seats, including seat heating and seat ventilation

General function requirements
^ C. 15R On

The circuit status is transmitted by the EIS [EZS] control unit (N73) via interior CAN to the left front seat adjustment control unit with memory (N32/1) or right front seat adjustment control unit wit memory (N32/2).

Seat ventilation, general
The seat cushions and backrests of the front seats can be ventilated in three stages using the seat ventilation.

During comfort opening of the vehicle, the seat ventilation of the driver seat is switched on in stage 3. If circuit 15R is not switched on at this time, the seat ventilation is switched off after t = 5 min.

The seat ventilation consists of the following subfunctions:
^ Manual on/off function sequence
^ Automatic switch off function sequence

Manual on/off function sequence
The actuation of the seat ventilation switch (S91/2s17) in the left seat adjustment switch group (S91/2) is read in by the left door control unit (N69/1) and the request is transmitted via interior CAN to the left front seat adjustment control unit.

The actuation of the seat ventilation switch (S92/2s17) in the right seat adjustment switch group (S92/2) is read in by the right door control unit (N69/2) and the request is transmitted via interior CAN to the right front seat adjustment control unit.

The left front seat adjustment control unit then actuates the left front seat ventilation blower regulator (N29/5), or the right front seat adjustment control unit then actuates the right front seat ventilation blower regulator (N29/6).

The left blower regulator actuates the following motor groups:
- Left front seat cushion ventilation motor group (M18/9)
- Left front seat backrest ventilation motor group (M18/10)

The right blower regulator actuates the following motor groups:
- Right front seat cushion ventilation motor group (M18/11)
- Right front backrest ventilation motor group (M18/12)

The seat ventilation depends on the ventilation stage selected using the seat ventilation switch:
Press once: Stage 3 of the seat ventilation
Press two times: Stage 2 of the seat ventilation
Press three times: Stage 1 of the seat ventilation
Press four times: Seat ventilation is switched off

The ventilation stage that has been activated is indicated by blue light-emitting diodes (LEDs) in the corresponding seat ventilation switch.

Automatic switch off function sequence
- Shutoff after circuit 15R Off:
If circuit 15C is still On, the timer control continues to run for t = 5 min. If circuit 15R is switched on again, the seat ventilation is also switched on in the previously activated ventilation stage.

- Shutoff in the event of undervoltage:
In the event of undervoltage, the left front seat adjustment control unit with memory or right front seat adjustment control unit with memory switches the seat ventilation off. The timer control continues to run, the LEDs in the seat ventilation switch are flashing with f = 1.5 Hz.

It is not possible to switch them on again until a permissible voltage is present again for t ≥ 20 s.

- Shutoff in the event of overvoltage:
In the event of overvoltage, the left front seat adjustment control unit with memory or right front seat adjustment control unit with memory switches the seat ventilation off.

The timer control continues to run, the LEDs remain on.

It is not possible to switch them on again until a permissible voltage is present again.

- Shutoff via on-board electrical system management:
In order to prevent the battery from discharging in all driving cycle phases, the state of charge is continuously monitored. Depending on the situation, the seat ventilation is also deactivated if necessary.

The timer control continues to run and the LEDs remain on.

- Shutoff at the end of diagnosis:
After the diagnosis has ended, the seat ventilation is switched off.