1 Series E81 118i (N46T) 3-door
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Head restraint angle adjustment (manual only)
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Adjustment of upper lumbar support (electropneumatic using lumbar cushion)
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Adjustment of lower lumbar support (electropneumatic using lumbar cushion)
All these functions are actuated by the buttons on the outside of the seat cushion. Signals from the respective
button trigger seat adjustment in the required directions.
Each drive is switched off when a certain threshold has been reached in order to reduce the load on the electric
drives to a minimum.
With the special equipment "Electric seat adjustment for driver's seat and front passenger's seat with memory for
driver's seat" the end stop is calculated for each drive. Hall sensors integrated in the drives register the
adjustment distances which are processed in the seat module. If the drive should become blocked, the detected
position value is interpreted as the end stop. All subsequent adjustments are interrupted just before this point.
Once the obstruction has been removed, adjustment can again extend beyond the newly detected end stop For
this to happen, the seat adjustment button must be pressed again.
If the "Seat memory" option is not installed, there will be neither a seat module nor Hall sensors fitted. End stops
are not stored with this equipment variant. The seat is adjusted until it reaches an end position. The junction box
electronics (JBE) recognises the increased power draw of the respective drive at the end position. If the power
draw exceeds a defined limit value, the JBE will switch this drive off.
A separate rocker switch is used to operate the lumbar support. An electric lumbar support pump supplies the
lumbar cushions with compressed air. The individual air chambers are filled or emptied via several valves in
order to vary the height and thickness of the lumbar support.
The seat back width adjustment is controlled by an additional rocker switch in the same way as lumbar support.
An electric lumbar support pump supplies the air cushions with compressed air. The individual air chambers are
filled or emptied via several valves
In this way the seat back width can be adjusted.
Seat heating
The seat heating system heats the seat cushion and backrest including the side sections.
The driver's seat and front passenger's seat each have a seat-heating switch in the centre console switch cluster
(SZM).
The junction box electronics (JBE) actuates the seat heating. The seat heating is activated by a pulse-width
modulated signal (PWM signal) from the seat heating module. The seat heating module records the temperature
in the seats via a temperature sensor. The seat heating module regulates the heat output according to the
selected heater level.
In the event of fault developing, the seat heating module will report the fault to the JBE. The seat heating module
indicates this with a pulsed short-circuiting in the signal wire. If the JBE detects a fault message, the heated seat
will be switched off. The JBE will store a fault memory entry.
Switching on again will reactivate the heated seat.
With the option "Electric seat adjustment for driver's seat and front passenger's seat with memory for driver's
seat", the seat heating module for the driver's side is replaced by the seat module. The seat module is
connected to the K-CAN via the junction box electronics. The seat module automatically assumes control of the
seat heating.
If a seat module is fitted, the junction box electronics is not responsible for adjusting the driver's seat.
The seat heating is operational as from terminal 15 ON.
3 LEDs located above the seat heating switches indicate the heating stage currently active in the seat heating
system.
SBT Electrically adjustable seats E81, E87, E90, E91, E92, E93
BMW AG - TIS
19.01.2013 06:24
Issue status (12/2007) Valid only until next DVD is issued
Copyright
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