Component description for driver seat control unit - GF91.29-P-5231FL

MODEL 212 with CODE 275 (Electrically adjustable front seats memory package) 

Shown on left seat 

Fig 1: Driver Seat Control Unit - Shown On Left Seat

Courtesy of MERCEDES-BENZ USA

Location 

The driver seat control unit is located at the bottom of the driver seat frame.

Task 

The driver seat control unit is responsible for the following tasks:

• Reading in of sensors and signals 
• Evaluation of input factors 
• Controlling functions 
• Actuation of components 

Reading in of sensors and signals 

The input factors are read in via the following connections:

• Direct line 
• Interior CAN (CAN B) 

Direct line 

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

• Steering column in/out Hall sensor (M20/1b1)
• Steering column up/down Hall sensor (M20/2b1)
• Seat fore/aft adjustment Hall sensor, driver seat (M27/1b1)
• Height adjustment Hall sensor, driver seat (M27/2b1)
• Inclination adjustment Hall sensor, driver seat (M27/3b1)
• Head restraint adjustment Hall sensor, driver seat (M27/4b1)
• Backrest inclination Hall sensor, driver seat (M27/5b1)

Interior CAN 

The signals are read in by the driver seat control unit over the interior CAN. The functions that use these signals are described in the individual function descriptions (see block diagram or function schematic).

Evaluation of input factors 

The read in input factors are evaluated by the driver seat control unit. The motors for seat and steering column adjustment are actuated via integrated relays.

Controlling functions 

The driver seat control unit controls the following functions:

• Seat and steering column adjustment
• Easy entry/exit
• Head restraint presetting
• Memory function for seat, outside mirrors and steering column
• Memory function for dynamic multicontour seat (with code (432) Left and right dynamic multicontour seat)
• Collision avoidance with the bench seat in rear (on model 212.0/1 with code (287) Through-loading feature or model 212.2)

Actuation of components 

The actuation of the components takes place via the following connections:

• Direct line 
• Interior CAN 

Direct line 

The following motors are actuated via direct lines:

• Steering column in/out adjustment motor (M20/1)
• Steering column up/down adjustment motor (M20/2)
• Driver seat fore/aft adjustment motor (M27/1)
• Driver seat height adjustment motor (M27/2)
• Driver seat inclination adjustment motor (M27/3)
• Driver seat head restraint adjustment motor (M27/4)
• Driver seat backrest inclination adjustment motor (M27/5)

Interior CAN 

The signals are sent by the driver seat control unit over the interior CAN. The functions that use these signals are described in the individual function descriptions (see block diagram or function schematic).