Lumbar support adjusting facility control unit, component description - GF91.29-P-5273GD

MODEL 204.0 /2 with CODE (275) Memory package (driver seat, steering column, mirrors) with CODE (242) Electrically adjustable front passenger seat with memory as of model year 2010 /YoM 09 

MODEL 204.3 /9 with CODE (275) Memory package (driver seat, steering column, mirrors) with CODE (242) Electrically adjustable front passenger seat with memory 

Location 

The lumbar support adjusting facility control unit is installed to the left of center in the corresponding seat backrest frame behind the backrest trim.

Task 

The lumbar support adjustment control unit regulates the air cushion pressures in both lumbar cushions of the particular front seat and stores the lumbar support contour stored last.

The lumbar support adjustment control unit tasks are split up as follows:

• Reading in of switches and signals 
• Evaluation of input factors 
• Actuation of components 
• Body 

Reading in of switches and signals 

The following switches are read in voltage-coded via direct lines:

• Driver seat lumbar support adjusting facility switch (S109/2)
• Front passenger seat lumbar support adjusting facility switch (S109/3)

Evaluation of input factors 

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

Actuation of components 

The driver seat lumbar support pneumatic pump (M25/4) or the front passenger seat lumbar support pneumatic pump (M25/5) are actuated via direct lines in order to control the compressed air supply.

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

Design 

In addition to the intelligent circuit, a pressure sensor is also located in the housing of the lumbar support adjustment control unit. This sensor is used for detecting and monitoring the pressure. The air pressures in the cushions are adjusted by the valves integrated in the lumbar support adjusting facility control unit. The lumbar support adjusting facility control unit is connected to the lumbar support adjusting facility switch on the seat via the 7-pin connector. It is also connected to the lumbar support pneumatic pump and the power supply via this connector.

	Lumbar support wiring diagram	Except model 204.0/2 with engine 156	PE91.29-P-2109-97FAA
		Model 204.0/2 with engine 156	PE91.29-P-2109-97FAB