Component description for lumbar support control unit - GF91.29-P-5281RF

MODEL 205, 253 with CODE 221 (Electrically adjustable left driver seat) with CODE 222 (Electrically adjustable right front seat)

MODEL 205, 253 with CODE 242 (Front passenger seat, electrically adjustable with memory function)

MODEL 205, 253 with CODE 275 (Memory package)

MODEL 205, 253 with CODE P65 (Seat comfort package)

Shown on front passenger seat

Fig 1: Identifying Seat Lumbar Support Adjustment Control Unit - Shown On Front Passenger Seat

Courtesy of MERCEDES-BENZ USA

Location

The lumbar support adjustment control units are centrally installed in the respective backrest frame behind the backrest trim.

Task

The lumbar support adjustment control units have the following tasks:

Control of the air cushion pressure in the lumbar support of the respective seat
Storage of last adjusted lumbar support contour
Control of the driver seat lumbar support pneumatic pump (M25/4) or front passenger seat lumbar support pneumatic pump (M25/5)

The tasks are subdivided as follows:

Reading in of sensors and signals
Evaluation of input factors
Actuation of components

Reading in of sensors and signals

The signals from the following components are read via direct lines:

Driver seat lumbar support adjustment switch (S109/2)
Front passenger seat lumbar support adjustment switch (S109/3)
Internal pressure sensor

Evaluation of input factors

The read-in input factors are evaluated by the respective lumbar support adjustment control unit. The air cushions in the seat are actuated via valves integrated in the respective lumbar support adjustment control unit.

Actuation of components

The actuation of the driver seat lumbar support pneumatic pump or front passenger seat lumbar support pneumatic pump for controlling the compressed air supply occurs via a direct line.

The air cushions in the seat are actuated via valves integrated in the respective lumbar support adjustment control unit.

Body

The air pressures in the cushions are adjusted by the valves integrated in the respective lumbar support adjustment control unit.

Wiring diagram for lumbar support control unit

PE91.29-P-2113-97FBA