Heated seats switch-off function - GF91.30-P-2001QB

MODELS 209.3 /4 as of 1.6.04 

with CODE (873) Electrically heated left and right front seats 

with CODE (401a) Front luxury seat, incl. heated seat and seat ventilation 

Function prerequisites: 

• The heated seats HS [SIH] are switched on

Automatic deactivation of the heated seats HS [SIH] via timer control 

The upper control panel control unit (N72/1) implements the timer control for the heated seats HS [SIH]:

• Heating stage 3 remains on for 5 min. After that, the system automatically switches to heating stage 2.
• Heating stage 2 remains on for 10 min. After that, the system automatically switches to heating stage 1.
• Heating stage 1 remains on for 20 min. After that, the heated seats HS [SIH] are automatically switched off.

Manual deactivation of the heated seats HS [SIH] 

Operate left front HS [SIH] switch (N72/1s10) or right front HS [SIH] switch (N72/1s11) as many times as needed to turn off the particular LEDs in the left front HS [SIH] switch (N72/1s10) or the right front HS [SIH] switch (N72/1s11).

The heated seats HS [SIH] are also switched off if the following criteria, which are listed in descending priority, apply: 

• Deactivation in the event of interior temperatures of higher than 30 °C 

If the upper control panel control unit (N72/1) receives the information "interior temperature > 30 °C" via the Controller Area Network Bus Class B (interior) (CAN-B):

• from the AAC [KLA] control and operating unit (N22) (without code (581b) comfort automatic air conditioning) or
• from the Comfort AAC (C-AAC [K-KLA]) control and operating unit (N22/7) (with code (581b) comfort automatic air conditioning), the heated seats HS [SIH] are switched off as long as this information is present.

• Deactivation in the event of a hardware defect 

  If the upper control panel control unit (N72/1) detects an internal warming of the power drivers of more than 85 °C or a power output of more than approx. 80 A (short circuit for approx. 200 ms), the heated seats HS [SIH] (load output only) are switched off. The LEDs in the left front HS [SIH] switch (N72/1s10) or in the right front HS [SIH] switch (N72/1s11) maintain their status. After 10 s, a new attempt is made to switch the system back on (actuation as before the fault occurred, if there was no change in the meantime, e.g., actuation of the left front HS [SIH] switch (N72/1s10) or the right front HS [SIH] switch (N72/1s11) or time has expired).

• Deactivation after ignition (circuit 15R) Off 

  After the ignition has been switched off, the heated seats HS [SIH] are switched off as well. However, the timer control continues running for 5 min, as long as circuit 15C is ON.

  If circuit 15R or circuit 15 are switched on again, the stage that is active based on the timer control is switched on with a delay of 2 s.

• Deactivation in the event of undervoltage 

  If falling below the undervoltage threshold for longer than 3 s, the heated seats HS [SIH] are switched off (timer control continues running). The heated seats can only be turned on again, after a permissible voltage is present for longer than 3 s.

  If undervoltage has been detected, all active LEDs in the left front HS [SIH] switch (N72/1s10) or the right front HS [SIH] switch (N72/1s11) flash on and off synchronously with a frequency of approx. 1.5 Hz and a brightness of 50%.

• Deactivation of the heated seats HS [SIH] during starting procedure 

During the starting procedure, the heated seats HS [SIH] are switched off (timer control continues running). After the starting procedure has been completed, the heated seats HS [SIH] are switched on again with a delay of 2 s.

If overvoltage was detected, they are not switched off.

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