Heated seats (HS) function - GF91.30-P-0003SX
MODEL 221.0 /1 with CODE (873) Heated left and right front seats with CODE (401) Front deluxe seats, incl. seat heating and seat ventilation with CODE (872) Electrically heated left and right rear seats with CODE (402) Rear deluxe seats, incl. seat heating and seat ventilation up to Model Year 8
Function
Using the integral heated seats (HS [SIH]), it is possible to heat the seat cushions and the backrests in three heating stages. The heated seat switches in the corresponding door panels are provided to switch the heated seats (HS [SIH]) on and off and to regulate the heat output. Every operation of the heated seat switches is transmitted by the corresponding door control unit via the interior CAN to the left front seat control unit, right front seat control unit or to the rear seats control unit.
Function requirements:
- C. 15R On
Switching on and selecting heated seats
- One-time actuation of heated seat switch activates stage 3 of heated seats (HS [SIH]). The corresponding heated seat cushion and backrest heated cushion are actuated with a heat output of 100 %. All 3 LEDs in the heated seat switch are actuated by the door control unit.
- Operating heated seat switch again sets heated seats (HS [SIH]) to stage 2. The corresponding heated seat cushion and backrest heated cushion are actuated with a heat output of 60 %. 2 LEDs in the heated seat switch are actuated by the door control unit.
- Another actuation of the heated seat switch activates stage 1 of heated seats (HS [SIH]). The corresponding heated seat cushion and backrest heated cushion are actuated with a heat output of 30 %. One LED in the heated seat switch is actuated by the door control unit.
Operating front passenger heated seat from driver seat (with code (275) Memory package (driver seat, steering column, mirrors))
The seat adjustment selection switch in left front seat operation switch group (S22) can be used to switch between the driver and front passenger seat adjustment functions.
The heated seats (HS [SIH]) are also among the selectable functions. Switchover is active for 10 s after operating the seat adjustment selection switch. This status is indicated by an LED. If a setting is made during this period, the switchover remains active for another 10 s following the end of the setting.
The switchover is also ended by operating the seat adjustment selection switch again.
Manual heated seats (HS) shut-off
The heated seats (HS [SIH]) can be switched off manually by operating the heated seat switches.
To do this, the corresponding heated seat switch must be operated repeatedly until all LEDs go off.
Automatic shutoff of heated seats (HS [SIH]) via timer control
The corresponding seat control unit and the rear seats control unit implement the timer control for the heated seats (HS [SIH]):
- Heating stage 3 stays on for 5 min. Then the system automatically switches to heating stage 2.
- Heating stage 2 stays on for 10 min. Then the system automatically switches to heating stage 1.
- Heating stage 1 stays on for 20 min. Then the heated seats (HS) are automatically switched off.
The heated seats (HS) are also shut off under the following criteria:
- Switching off as under terminal 15R OFF
If circuit 15C remains On, timer control continues to run for 5 min. If circuit 15R is now switched on again, then heated seats (HS [SIH]) are also switched on at the active heating stage in accordance with the timer control setting.
- Switching off in the event of undervoltage
The timer control continues to run if the heated seats (HS [SIH]) are switched off due to undervoltage. The LEDs flash while there is an undervoltage.
- Switching off at seat adjustment
When the seat adjustment is actuated, the heated seats (HS [SIH]) (load only) are switched off. The timer control continues to run during the seat adjustment, the LEDs remain on.
- Switching off during starting procedure
During the starting procedure, the heated seats (HS [SIH]) are switched off (load only). The timer control continues to run during the starting procedure, the LEDs also remain on. During the starting procedure, undervoltage is not detected and no flashing due to undervoltage is activated.
- Switching off in the event of overvoltage
The timer control continues to run if the heated seats (HS [SIH]) are switched off due to overvoltage.
- Shutting off with code (889) Keyless Go
As faults may occur during the inductive search for the transmitter key (A8/1) in the passenger compartment, the heated seats (HS [SIH]) are switched off during this period.
When the search has ended, the heated seats (HS [SIH]) are switched on again.
- Switching off by the on-board electrical system (consumer shutoff)
To prevent the battery from discharging in any driving cycle phase, the state of charge of the on-board electrical system is assessed continuously. The vehicle power supply control unit (N82/1) shuts off high-power consumers in a fixed sequence until the undervoltage no longer exists. This also applies to the heated seats (HS [SIH]).
| Heated seats (SIH) location of components | GF91.30-P-0003-02SX | ||
| Heated seats (HS) block diagram | GF91.30-P-0003-03SX | ||
| Rear seats control unit, component description | N25/6 For vehicles with code (872) Electrically heated left and right rear seats or with code (402) Rear deluxe seats, incl. seat heating and seat ventilation |
GF91.29-P-5250SXA | |
| Left front seat control unit, component description | N32/1 | GF91.29-P-5230SX | |
| Right front seat control unit, component description | N32/2 | GF91.29-P-5240SX | |
| Driver-side front door control unit, component description | N69/1 | GF72.29-P-6000SX | |
| Passenger-side front door control module, component description | N69/2 | GF72.29-P-6010SX | |
| Rear door control module component description | N69/3, N69/4 | GF72.29-P-6020SX | |
| Electronic ignition/starter switch control unit (EIS) component description | N73 | GF80.57-P-6000SX | |
| Front seat adjustment switch group, component description | S22, S23 | GF91.29-P-5220SX | |
| Rear seat adjustment switch group, component description | S55/1, S55/2 For vehicles with code (872) Electrically heated left and right rear seats or with code (402) Rear deluxe seats, incl. seat heating and seat ventilation |
GF91.29-P-5216SXA |