Component description for front passenger seat control unit - GF91.29-P-5241FL

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

Shown on right seat 

Fig 1: Front Passenger Seat Control Unit - Shown On Right Seat

Courtesy of MERCEDES-BENZ USA

Location 

The front passenger seat control unit is located beneath the seat cushion at the frame of the front passenger seat.

Task 

The front passenger 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:

• Seat fore/aft adjustment Hall sensor, front passenger seat (M28/1b1)
• Height adjustment Hall sensor, front passenger seat (M28/2b1)
• Front passenger seat inclination adjustment motor Hall sensor (M28/3b1)
• Head restraint adjustment Hall sensor, front passenger seat (M28/4b1)
• Backrest inclination Hall sensor, front passenger seat (M28/5b1)

Interior CAN 

The signals are read in by the front passenger 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 input factors that have been read in are evaluated by the integrated microprocessor and the relevant components are then actuated.

Controlling functions 

The front passenger seat control unit controls the following functions:

• Front passenger seat adjustment
• Storing the front passenger seat memory settings
• Store the memory settings for dynamic multicontour seat (with code (432) Left and right dynamic multicontour seat)
• Head restraint presetting
• Collision avoidance with the bench seat in rear (on model 212.0/1 with code (287) Through-loading feature or model 212.2)
• Actuating PRE-SAFE positioning function for front passenger seat

Information on the PRE-SAFE positioning function of the front passenger seat can be found in the function description "PRE-SAFE, function".

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:

• Front passenger seat fore/aft adjustment motor (M28/1)
• Front passenger seat height adjustment motor (M28/2)
• Front passenger seat inclination adjustment motor (M28/3)
• Front passenger seat head restraint adjustment motor (M28/4)
• Front passenger seat backrest inclination adjustment motor (M28/5)

Interior CAN 

The signals are transmitted by the front passenger seat control unit via the interior CAN. The functions that use these signals are described in the individual function descriptions (see block diagram or function schematic).