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Component Description For Lumbar Support Control Unit - GF91.29-P-5281FG

Model 213 

up to model year 2021 

with code 221 (Electrically adjustable left driver seat) 

with code 222 (Electrically adjustable right driver seat) 

Model 213 

up to model year 2021 

with code 275 (Memory Package (driver's seat, steering column and mirror)) 

except code 432 (Dynamic seats left and right) 

Model 213 

up to model year 2021 

with code P65 (Seat comfort package) 

Fig 1: Lumbar Support Control Unit Components Location - Model 213 Up To Model Year 2021 With Codes 221, 222, 275 And P65; Except With Code 432
G13775776Courtesy 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:

The tasks are subdivided as follows:

Read in sensors and signals 

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

Evaluation of input factors 

The read-in input factors are evaluated by the respective lumbar support adjustment control unit. The relevant components are then actuated.

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.

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

  Wiring diagram for lumbar support control unit   PE91.29-P-2113-97DBA