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

MODELS 203.0 /2 /7 as of 24.4.04 with CODE (873) Electrically heated left and right front seats 

Function prerequisites: 

• The heated seats (HS) are switched on.

Automatic shut-off of heated seats (HS) via timer control 

The upper control panel control unit (N72/1) implements the timer control for the heated seats (HS).

• 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 heating time for heating stage 1 can be programmed using the diagnosis facility.

Manual heated seats (HS) shut-off 

Operate left front HS switch (N72/1s10) and right front HS switch (N72/1s11) until the respective LEDs in the left front HS switch (N72/1s10) and the right front HS switch (N72/1s11) go off.

The heated seats (HS) are also switched off depending on the following criteria, which are listed in descending priority order: 

• Switching off in the event of a hardware defect 

In order to prevent the heated seats from being switched on if a plug falls out or a heated seats (HS) cable is sheared off, the resistance value at the driver level output is checked at frequent intervals. If the resistance value is too high the left front HS switch (N72/1s10) and the right front HS switch (N72/1s11) are no longer inquired by the upper control panel control unit (N72/1).

• Switch off at an interior temperature of more than 40°C 

If the upper control panel control unit (N72/1) receives the information "interior temperature > 40°C":

• from the AAC control and operating unit (N22) (without code (581b) comfort automatic air conditioning)
• or the comfort AAC control and operating unit (N22/7) (with code (581b) comfort automatic air conditioning)

the heated seats (HS) are shut off.

• Shut-off after ignition (circuit 15R) off 

When the ignition is switched off, the heated seats (HS) are also switched off. However, the timer control continues to run for a further 5 minutes as long as circuit 15C is on.

If terminal or terminal 15 is switched now on again, the active stage is also switched on again in accordance with the timer control setting after a 2-second delay.

• Switching off in the event of undervoltage 

If the undervoltage threshold of 11 V is exceeded for longer than 3 seconds the heated seats (HS) are shut off (timer control continues to run).

If undervoltage is detected the active LED's in the left front HS switch (N72/1s10) and the right front HS switch (N72/1s11) flash at a frequency of approximately 1.5 Hz and brightness of 50%. The heated seats cannot be switched on again until a permissible voltage of 11.5 V has been present for longer than 3 seconds.

• Switching off in the event of overvoltage 

The heated seats (HS) become active again if the overvoltage threshold of 16 V is exceeded. The active LEDs in the left front HS switch (N72/1s10) and the right front HS switch (N72/1s11) are no longer powered to prevent a fault from occurring.

• Shutting off heated seats (HS) during starting procedure 

The heated seats (HS) are switched off during the starting procedure (timer control continues to run). After starting has taken place the heated seats (HS) are switched on again after a 2-second delay.

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