Component description for front passenger seat control unit

P91.29-2811-04

Location

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

Task

The front passenger seat control unit is responsible for the following tasks:

 Control of the seat adjustment

 Storing of the memory settings for the front passenger seat (model 222 with code 275 (Memory package) or model 217)

 Actuation of collision avoidance

 Actuating PRE-SAFE® positioning function for front passenger seat

The tasks are subdivided as follows:

 Read in sensors and signals

 Evaluation of input factors

 Actuation of components

Read in sensors and signals

The input factors are read in via the following connections:

 Direct line

 Interior CAN (CAN B)

Direct line

The front passenger seat control unit reads in the signals from the following sensors over direct lines:

 Front passenger seat fore/aft adjustment Hall sensor 1 (M28/1b1)

 Front passenger seat fore/aft adjustment Hall sensor 2 (M28/1b2)

 Head restraint adjustment Hall sensor, front passenger seat (M28/4b1)

 Backrest inclination Hall sensor, front passenger seat (M28/5b1)

 Cushion length adjustment Hall sensor, front passenger seat (M28/8b1) (model 222 with code 275 (Memory package) or model 217)

 Seat inclination adjustment Hall sensor, front passenger seat (M28/9b1)

 Seat height adjustment Hall sensor, front passenger seat (M28/10b1)

 Front passenger seat head restraint angle Hall sensor (M79/2b1) (model 222 with code 439 (EASY ADJUST luxury head restraint))

 Screen adjustment Hall sensor (M86b1) (model 222 with code 864 (Rear Seat Entertainment system))

 Footrest setting Hall sensor (M104b1) (model 222 with code P07 (Chauffeur package))

 Right front seat cushion heater pad temperature sensor (R133b1/) (from model year 2018 with code 902 (Seat heater Plus for driver and front passenger))

 Right front backrest heater pad temperature sensor (R134b1/) (from model year 2018 with code 902 (Seat heater Plus for driver and front passenger))

 Head restraint microswitch (plugged in), front passenger seat (S52/7) (model 222 with code 439 (EASY ADJUST luxury head restraint))

 Front passenger head restraint angle microswitch (S82/2) (model 222 with code 439 (EASY ADJUST luxury head restraint))

 Right backrest release/backrest inclination microswitch (S92/6) (model 217)

Interior CAN

The front passenger seat control unit reads in the following signals via interior CAN, among other things:

 Seat adjustment request

 Request for storing/moving to memory position (model 222 with code 275 (Memory package) or model 217)

 Seat heater request (model 222 with code 401 (Seat climate control for driver and front passenger) or code 873 (Seat heater for driver and front passenger) or code 432 (Left and right front dynamic multicontour seat) or model 217)

 Seat ventilation request with CODE 401 (Seat climate control for driver and front passenger))

 PRE-SAFE® positioning function request

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 front passenger seat control unit. The seat adjustment motors are actuated via integrated relays.

Actuation of components

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

 Direct line

 Front passenger seat LIN (LIN B19)

 Interior CAN

Direct line

The front passenger seat control unit actuates the following components via direct lines:

 Front passenger seat fore/aft adjustment motor (M28/1)

 Front passenger seat head restraint adjustment motor (M28/4)

 Front passenger seat backrest inclination adjustment motor (M28/5)

 Front passenger seat cushion length adjustment seat adjustment motor (M28/8) (model 222 with code 275 (Memory package) or model 217)

 Seat inclination adjustment motor, front passenger seat (M28/9)

 Seat adjustment motor, seat height adjustment, front passenger seat (M28/10)

 Front passenger seat head restraint angle motor (M79/2) (model 222 with code 439 (EASY ADJUST luxury head restraint))

 Screen adjustment actuator motor (M86) (model 222 with code 864 (Rear Seat Entertainment system))

 Footrest setting actuator motor (M104) (model 222 with code P07 (Chauffeur package))

 With CODE 401 (Seat climate control for driver and front passenger):

 Right front seat cushion seat ventilation motors (M18/11)

 Right front backrest seat ventilation motors ( M18/12)

 Model 222 with code 401 (Seat climate control for driver and front passenger) or code 873 (Seat heater for driver and front passenger) or code 432 (front left and right dynamic multicontour seat) or model 217:

 Right front seat cushion heater pad (R13/3)

 Right front backrest heated cushion (R13/4)

Front passenger seat LIN

The front passenger seat control unit communicates via the front passenger seat LIN with the front passenger seat lumbar support adjustment control unit (N32/24) and for vehicles with code 432 (Left and right dynamic multicontour seat) with the front passenger seat heater control unit (N25/4).

Interior CAN

The front passenger seat control unit sends the following signals via interior CAN, among other things:

 Request for acknowledge tone after storage in memory (model 222 with code 275 (Memory package) or model 217)

 Seat position status

 Seat heater status (model 222 with code 401 (Seat climate control for driver and front passenger) or code 873 (Seat heater for driver and front passenger) or code 432 (Left and right dynamic front multicontour seat) or model 217)

 Seat ventilation status (with CODE 401 (Seat climate control for driver and front passenger))

Variants

There are no variants for the hardware of the front passenger seat control unit. The country or left-hand drive vehicle/right hand drive vehicle allocation is software coded.