Switch on seat heater, function

Function requirements:

 C. 15R On

Function of heated driver or front passenger seats

Pressing the left front HS [SIH] switch (N72/1s10) or the right front HS [SIH] switch (N72/1s11) is read in by the upper control panel control unit (N72/1).

The upper control panel control unit forwards the switch-on command, depending upon the number of operations, via the Controller Area Network bus class B (interior) (CAN-B) to the

 passenger-side SAM control unit (N10/11)
(on vehicles as of 1.6.05 without code (872) Electrically heated left and right rear seats and without code (401) Front deluxe seats, incl. seat heating and seat ventilation) or to the

 HS [SIH] and seat ventilation control unit (N25/7)
(on vehicles up to 31.5.05 and on vehicles with code (401) Front deluxe seats, incl. seat heating and seat ventilation),

which actuates the integrated heated cushions (R13/1, R13/2 or R13/3, R13/4).

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The feedback of the switched-on heating stage is transmitted via the integrated LEDs in the left front HS [SIH] switch or in the right front HS [SIH] switch.

Switching on the heated driver or front passenger seats as a function of the interior temperature

 Interior temperature > 42 °C:
When stage 3 is switched on, stage 2 is switched on automatically.

 Interior temperature > 45 °C:
When stage 2 is switched on, stage 1 is switched on automatically.

 Interior temperature > 55 °C:
Heated seats HS [SIH] can no longer be switched on.

 If the value for the interior temperature is not available, the value of the outside temperature is used as a backup.

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Function of the left rear seat heater

(with code (872) Electrically heated left and right rear seats)

Pressing the left rear HS [SIH] switch (S51/3s2) is read in by the left rear door control unit (N69/3) via the switching bus, which forwards the switch-on command to the HS [SIH] and seat ventilation control unit (N25/7) via CAN-B depending upon the number of operations.

The HS [SIH] and seat ventilation control unit actuates the integrated heated cushions (R13/5, R13/6, and R13/9).

The feedback of the switched-on heating stage is transmitted via the integrated LEDs in the left rear HS [SIH] switch.

Function of the right rear seat heater

(with code (872) Electrically heated left and right rear seats)

Pressing the right rear HS [SIH] switch (S51/4s2) is read in by the right rear door control unit (N69/4) via the switching bus, which forwards the switch-on command to the HS [SIH] and seat ventilation control unit via CAN-B depending upon the number of operations.

The HS [SIH] and seat ventilation control unit actuates the integrated heated cushions (R13/7, R13/8, and R13/10).

The feedback of the switched-on heating stage is transmitted via the integrated LEDs in the right rear HS [SIH] switch.

 The operating and function indications of the heated seats (HS) are summarized in the table given below.