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Lumbar Support Control Unit, Component Description - GF91.29-S-5281A

Model 447 

With Code SE4 (Lumbar support for co-driver's seat) 

With Code XM7 (MOPF II) 

Model 447 

With Code SE5 (Lumbar support for driver's seat) 

With Code XM7 (MOPF II) 

IMPORTANT The numbers on the pins indicate the pin numbering of the slots.

Driver's seat/front passenger seat lumbar support adjustment control unit, shown on model 447.8 

Fig 1: Lumbar Support Control Unit Components Location - Model 447 With Code SE4, SE5, XM7
G16502097Courtesy of MERCEDES-BENZ USA

Overview 

This document contains information on:

General 

The driver's seat lumbar support adjustment control unit (N32/23) and front passenger seat lumbar support adjustment control unit (N32/24) are installed in the respective seat backrest.

Function 

The driver's seat lumbar support adjustment control unit (N32/23) and the front passenger seat lumbar support adjustment control unit (N32/24) are responsible for controlling the lumbar support cushion installed in the seat backrest.

The lumbar support cushions are pumped up to meet requirements by actuating the driver's seat lumbar support pneumatic pump (M25/4) and front passenger seat lumbar support pneumatic pump (M25/5).

The following input parameters and initial parameters are read in and output over direct lines from the driver's seat lumbar support adjustment control unit (N32/23):

Input parameters over a direct line Initial parameters over a direct line
Terminal 30t -
Terminal 31 -
- Driver's seat lumbar support pneumatic pump actuation (M25/4)
Driver's seat lumbar support adjustment switch signal (S204) -
- Driver's seat lumbar support adjustment switch ground connection (S204)

The following input parameters and initial parameters are read in and output over direct lines from the front passenger seat lumbar support adjustment control unit (N32/24):

Input parameters over a direct line Initial parameters over a direct line
Terminal 30t -
Terminal 31 -
- Front passenger seat lumbar support pneumatic pump actuation (M25/5)
Front passenger seat lumbar support adjustment switch signal (S204/1) -
- Front passenger seat lumbar support adjustment switch ground connection (S204/1)

Ground connection 

The "Terminal 31" ground connection is made through the auxiliary battery ground point (W10/4) and the right vehicle interior firewall ground point 2 (W43/5).

Power supply 

The "circuit 30t" power supply is provided via the firewall fuse and relay module (K40/11).