Electrically Operated Front Seats With Memory
85BMW10GROUP 52 Seats
Bulletin Number 52 02 85 (2041) Page 1 of 3
Montvale, NJ September 1985 Technical Dept.
SUBJECT: Electrically Operated Front Seats with Memory
Electrically operated front seats with a programmable memory feature are now available in certain BMW models. With this feature it is possible to program and select 10 different seat positions in each of the 3 separate memories.
Besides permitting automatic resumption of an individuals' seating position, the programmable memory feature can also be used to program and select different seat positions for long-distance and city driving.
Seat positions which can be programmed: - seat cushion height, front and rear
- seat positioning, forward/back
- backrest inclination
- headrest height
The switch unit, located in the center console, is used to program and store positioning data. The positioning signals for the electric motors are then stored and constantly monitored in the central electronic control unit. The control unit is mounted underneath the front seat. A pre-selected seat position is recalled by pressing one of the three SELECT push buttons (5).
1 = Memory "store" buttons (3) _
2 = STOP button
3 = LED (green) for function control
4 = LED (red) for malfunction display
5 = SELECT buttons (3)
Programming Seat Positions
With the ignition key in position 1 (accessory) or 2 (ignition "on"):
1. adjust seat to the desired position;
2. press one of the recessed memory buttons with a ball point pen to store this position in the memory. Acceptance of the seat position into memory is indicated by the flashing green LED (at which time the memory button may be released.) This position can now be recalled by pushing the corresponding SELECT button.
Selecting Programmed Seat Positions
There are two ways in which to select one of the 3 programmed seat positions:
1. With the ignition key in position 1 or 2 (engine not running) depressing one of the SELECT buttons will automatically move the seat into that programmed position without interruption.
2. With the engine running, the SELECT button for the desired seat position must be held down until that programmed position is reached.
During automatic SELECT (see point 1) the green LED will be on until the programmed seat position has been reached and then go out.
When selecting a programmed seat position with the engine running (see point 2) a flashing green LED will be displayed upon reaching the programmed seat position.
The red LED will come on to indicate malfunctions in the program or a defect in the system.
To switch off the entire electrical operating program in case of a malfunction, depress the STOP button. It can also be used to interrupt each unwanted seat positioning sequence.
Operating another SELECT push button during the automatic seat positioning sequence will immediately stop the program. The desired SELECT push button must then be pressed again to complete the automatic seat positioning program.
The manual control buttons for individual seat adjustment override the memory electronic unit and will stop a previously selected programmed seat position. Consequently, do not depress the manual control push buttons when the seat is in the automatic positioning mode.
Function
The position of the electric motors are reported to the memory circuit via potentiometers inside the electric motors.
After pressing the SELECT push button the memory reports the positions to the different electric motors for adjustment of the seat and/or backrest position accordingly.
Technical Data
Closed circuit current of electronic unit approx. 3mA
Operating current up to 1.3 A
Fuse 25 amps
Operating voltage 10 - 15 V