Switch off seat heater, function

Function requirements:

 The heated seats (HS) are switched on.

Automatic switch-off 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.

-----------------------------------------------------------------------------------------

Switching off manually

Press left front HS [SIH] switch (N72/1s10) or right front HS [SIH] switch (N72/1s11) repeatedly until the respective LEDs in the left front HS [SIH] switch (N72/1s10) or right front HS [SIH] switch (N72/1s11) go out. The heated seats (HS) can be switched off at any time.

-----------------------------------------------------------------------------------------

The heated seats (HS) are also shut off under the following criteria:

 Switch-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 circuit 15R or circuit 15 are switched on again, then the active stage is switched on again according to the timer control.

 Switching-off in event of short circuit

If a load of more than approx. 80 A is detected at a power output (short circuit for approx. 200 ms), then it is switched off (timer control continues to run). If no other change (end of timer control or heated seats (HS) are switched off via the left front HS [SIH] switch (N72/1s10) or the right front HS [SIH] switch (N72/1s11)), another attempt is made after 10 s and this power output is actuated again.

-----------------------------------------------------------------------------------------

 Switching-off in event of hardware fault

In order to be able to detect a plug fallen out or a line sheared off, the electronics' output in the upper control panel control unit (N72/1) is checked every 10 ms at the applied resistor. If the measured resistance value is < 500 Ω, the heated seats (HS) are deemed to be connected. If the measured resistance value is > 2 kΩ, then the left front HS [SIH] switch (N72/1s10) and the right front HS [SIH] switch (N72/1s11) are no longer queried. The heated seats (HS) can thus no longer be used.

 Switching-off in case of undervoltage

If the voltage drops below the undervoltage threshold of approximately 10 V for 2 s, the heated seats (HS) (only load) are switched off (timer control continues to run). If the voltage lies above 11.5 V for 3 s, then the heated seats (HS) are switched on again. Undervoltage detection is indicated by the flashing on and off of the respective LEDs in the left front HS [SIH] switch (N72/1s10) or right front HS [SIH] switch (N72/1s11), at a frequency of approx. 1.5 Hz and 50 % brightness.

-----------------------------------------------------------------------------------------

 Switching-off during starting procedure

The power supply is switched off during the starting procedure (timer control continues to run).

 Switching-off in case of overvoltage

If the overvoltage threshold of approximately 16 V is exceeded for 2 s, the heated seats (HS) are switched off (timer control continues to run).