Component description for front passenger seat control unit

 The component description for the front passenger seat control unit (N32/2) describes a left-hand drive vehicle. Right-hand drive vehicles are to be observed mirror inverted with regard to the designations of the electric components.

P91.29-2861-04

Location

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

Tasks

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

 Control of the seat adjustment

 Saving/calling up memory settings for the front passenger seat (with code 242 (Electrically adjustable front passenger seat with memory function))

 Control of collision avoidance feature (model 205.0/1 with code 287 (Folding rear seat backrests) and code 242 (Electrically adjustable front passenger seat with memory function), model 205.2/3/4, 253 with code 242 (Electrically adjustable front passenger seat with memory function))

 Move to PRE-SAFE® positioning function for front passenger seat (with CODE 299 (PRE-SAFE® system) and CODE 242 (Electrically adjustable front passenger seat with memory function))

The tasks are subdivided as follows:

 Reading in of sensors and signals

 Evaluation of input factors

 Actuation of components

 Transmitting signals

Reading in of sensors and signals

The input factors are read in via the following connections:

 Direct line

 Heater LIN (LIN B28) (with CODE 222 (Electrically adjustable right front seat))

 Interior CAN (CAN B) (with CODE 242 (Electrically adjustable front passenger seat with memory function))

Direct line

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

With CODE 242 (Electrically adjustable front passenger seat with memory function):

 Seat fore/aft adjustment Hall sensor, front passenger seat (M28/1b1)

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

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

 Seat cushion length adjustment Hall sensor, front passenger seat (M28/8b1)

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

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

 Right backrest release microswitch (S92/6s1) in the right backrest release/backrest inclination microswitch (S92/6) (model 205.3/4)

 Right backrest inclination microswitch (S92/6s2) in the right backrest release/backrest inclination microswitch (model 205.3/4)

Heater LIN (with CODE 222 (Electrically adjustable right front seat))

The front passenger seat control unit reads in the following signals from the rear SAM control unit (N10/8) via the heater LIN, among other things:

 Seat adjustment request

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

 Seat heater request (with CODE 401 (Seat climate control for driver and front passenger) or CODE 873 (Seat heater for driver and front passenger))

The functions that use these signals are described in the individual function descriptions (see block diagram or function schematic).

Interior CAN (with CODE 242 (Electrically adjustable front passenger seat with memory function))

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

 Status of rear seat backrest (model 205.0/1 with code 287 (Folding rear seat backrests), model 205.2/3/4, 253)

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 following components are actuated via direct lines:

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

 Front passenger seat head restraint adjustment seat adjustment motor (M28/4) (with CODE 242 (Electrically adjustable front passenger seat with memory function))

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

 Front passenger seat seat cushion length adjustment seat adjustment motor (M28/8) (with CODE 242 (Electrically adjustable front passenger seat with memory function))

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

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

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)

With CODE 401 (Seat climate control for driver and front passenger) or CODE 873 (Seat heater for driver and front passenger):

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

 Right front seat backrest heater pad (R13/4)

 Right front seat adjustable seat cushion length heater pad (R24/1)

Transmitting signals

The front passenger seat control unit sends signals via the following connections:

 Heater LIN (with CODE 222 (Electrically adjustable right front seat))

 Interior CAN (with CODE 242 (Electrically adjustable front passenger seat with memory function))

Heater LIN (with CODE 222 (Electrically adjustable right front seat))

The front passenger seat control unit sends the following signals via the heater LIN to the rear SAM control unit, among other things:

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

 Seat heater status (with CODE 401 (Seat climate control for driver and front passenger) or CODE 873 (Seat heater for driver and front passenger))

The functions that use these signals are described in the individual function descriptions (see block diagram or function schematic).

Interior CAN (with CODE 242 (Electrically adjustable front passenger seat with memory function))

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

 Request for acknowledge tone after storage in memory

 Seat position status

The functions that use these signals are described in the individual function descriptions (see block diagram or function schematic).

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.