GF91.30-P-2001QA Heated Seats Switch-Off Function

GF91.30-P-2001QA Heated Seats Switch-off Function
- with CODE (873) Electrically heated left and right front seats
- with CODE (401a) Front luxury seat, including heated seat and seat ventilation
- as of 2.6.03
- up to 31.5.04

Function prerequisites:
^ The heated seats HS [SIH] are switched on.

Automatic deactivation of the heated seats HS [SIH] via timer control
A timer control has been implemented in the upper control panel control unit (N72/1) for the heated seats HS [SIH]. After switching on heating stage 2, it remains switched on for 5 min. Next, the system switches to heating stage 1 for 30 min. Afterwards, the heated seats HS [SIH] are switched off automatically.

In vehicles with code (401a) front deluxe seats, incl. seat heating and seat ventilation, the heated seats HS [SIH] are not automatically switched off based on the timer control, but remain active on heating stage 1 until the seat ventilation is switched off.

Manual deactivation of the heated seats HS [SIH]
The heating operation of the heated seats HS [SIH] is manually switched off (both red LEDs off) by operating the left front HS [SIH]/seat ventilation switch (N72/1s28) or the right front HS [SIH]/seat ventilation switch (N72/1s29).

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

deactivation at interior temperatures > 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] (loads output only) that are switched on are switched off as long as this information applies.

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]/seat ventilation switch (N72/1s28) or in the right front HS [SIH]/seat ventilation switch (N72/1s29) 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]/seat ventilation switch (N72/1s28) or the right front HS [SIH]/seat ventilation switch (N72/1s29) or time has expired).

Deactivation after circuit 15R Off
After deactivating circuit 15R, the heated seats HS [SIH]
(load output and function indicator) are switched off. However, the internal timer control continues running for 5 min, as long as circuit 15C is ON. If circuit 15R or circuit 15 is switched on again, the heated seats HS [SIH] are switched on again in the timer control activated stage.

Deactivation in the event of undervoltage
If falling below the undervoltage threshold for 3 s, the heated seats HS [SIH] (load output only) are switched off. The timer control continues running, if the heated seats HS [SIH] are switched off due to undervoltage. The bits for the function indicator are set accordingly. The heated seats can only be turned on again, after a permissible voltage is present for 3 s. If undervoltage is detected, the particular LEDs that are active flash on and off with approx. 1.5 Hz and 50% brightness. The flashing cycle of the LEDs in the left front HS [SIH]/seat ventilation switch (N72/1s28) and right front HS [SIH]/seat ventilation switch (N72/1s29) is synchronous. If undervoltage is detected for 30 s, the corresponding error is stored in the fault memory.

Deactivation during the starting procedure
During the starting procedure, the heated seats HS [SIH] (load output only) are switched off; the 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. The LEDs remain actuated during the starting procedure.