不可解な電動シートトラブル Strange thing on Electric seat
the memory module is under the driver seat, if you take out the seat, the module comes with the seat.
We just fixed the seat memory problem on an Alpina B12 with sports seats, stay tune, interesting pics and findings, the problem of not being able to use the memory function and eratic seat movement was not the memory module, not the plugs going into the memory module, but this part
The actual position of the motors is fed back to the control unit with potentiometers which are integrated into the motors.
These potentiometers were not good anymore, not the electric part, but the plastic gears, broken teeth. That confused the whole system.
The gearboxes of the potentiometers are adapted to the adjusting travel in order to utilize the maximum potentiometer ranges.
Potentiometer gear boxes must have different ratios for the identical potentiometer travel, since the adjusting travel of a headrest is different than the adjusting travel for axial seat movement. This difference in gearbox travel is marked on the plug/motor with different colors of paint. We actually tried a headrest potentiometer for seat movement, it did not work, till be found out the difference.
All restoring potentiometer paths have a fixed resistance of 4.7 k-ohms.
The potentiometer voltage must rise in the case of positive movement direction for the seat adjusting plane.
-Seat height up
-Inclination front up
The following is applicable to mirror drive:
-Horizontal to the right
The following labels are used on the potentiometer housings for identification of the different ratios:
headrest: red, potentiometer gearbox ratio 255
seatheight:red, " " 255
backrest:green, ratio 731
forward/backward: brown, ratio 1125
inclination:black, ratio 146.6
ラベル: Electric power seat