GF91.30-P-0002CE Electric Seat Ventilation, Function
GF91.30-P-0002CE Electric Seat Ventilation, Function
M18/9 Left front seat cushion seat ventilation motors
M18/10 Left front backrest seat ventilation motors
M18/11 Right front seat cushion seat ventilation motors
M18/12 Right front backrest seat ventilation motors
N10/1 Front SAM control unit with fuse and relay module
N10/2 Rear SAM control unit with fuse and relay module
N29/5 Left front seat ventilation blower regulator
N29/6 Right front seat ventilation blower regulator
N72/1 Upper control panel control unit
N72/1s13 Left front seat ventilation button
N72/1s14 Right front seat ventilation button
N73 Electronic ignition switch control unit
CAN B Interior CAN
LIN 1 Instrument panel LIN
Function requirements, general
- Circuit 15R ON
The status of circuit 15 is provided by the electronic ignition lock control unit via interior CAN.
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.
More detailed information can be found in the function description for the convenience feature (CF [KFB]).
The electric seat ventilation function comprises the following subfunctions:
- Function sequence, switching on, over and off manually
- Function sequence for automatic switch off
Function sequence, switching on, over and off manually
The seat ventilation is switched on and off with the left seat ventilation button and right front seat ventilation button in the upper control panel control unit and the ventilation output is regulated. Each actuation of the corresponding seat ventilation button is transmitted by the upper control panel control unit via the instrument panel LIN to the front SAM control unit. It then transmits the request via interior CAN to the rear SAM control unit. The rear SAM control unit then actuates the left front seat ventilation blower regulator or right front seat ventilation blower regulator.
The following motor groups are actuated by the left front seat ventilation blower regulator:
- Left front seat cushion seat ventilation motors
- Left front backrest seat ventilation motors
The following motor groups are actuated by the right front seat ventilation blower regulator:
- Right front seat cushion seat ventilation motors
- Right front backrest seat ventilation motors
The seat ventilation depends on the ventilation stage selected by means of each seat ventilation button. The function indication for each activated ventilation stage is effected through three blue LEDs in each seat ventilation button.
Press once: Stage 3 of seat ventilation, 3 LEDs light up
Press two times: Stage 2 of seat ventilation, 2 LEDs light up
Press three times: Stage 1 of seat ventilation, 1 LED lights up
Press four times: Seat ventilation is switched off, no LEDs light up
Function sequence for automatic switch off
- Shutoff after circuit 15R OFF.
If circuit 15C remains on, the timer control runs on for t = 5 min. If circuit 15R is switched on again, the seat ventilation is also switched on in the previously activated ventilation stage.
- Switching off by on-board electrical system management system.
In order to prevent the battery from discharging in all driving cycle phases, the state of charge is continuously evaluated. Depending on the situation, the seat ventilation is also deactivated if necessary.
- Shutting off in the event of undervoltage or overvoltage.
If the rear SAM control unit switches off the seat ventilation motors, the LED for each seat heater button initially stays on. If the on-board electrical system reaches its normal voltage within the next t = 3 min., the seat ventilation function is automatically reactivated.
However, if the shutoff lasts longer than t = 3 min., the LED in the seat ventilation button is also switched off.
It the shutoff procedure continues and the function is requested again for the corresponding seat ventilation button, the LED comes on for t = 1.5 s and then goes out.
- Shutting off during the engine starting procedure.
During a start sequence, only the seat ventilation motors are switched off. The LEDs in the function indicator are still illuminated. Undervoltage is not recognized while starting and no faults are stored.
