Driver Seat Control Unit, Component Description - GF91.29-S-5231TRA

Model 447

With Code H16 (Seat heater for driver)

Model 447

With Code SF1 (Driver's seat electrically adjustable)

Model 448.8

With Code H16 (Seat heater for driver)

Model 448.8

With Code SF1 (Driver's seat electrically adjustable)

Shown on model 447.8 With Code SF1 (Electrically adjustable luxury driver seat) and without code ZM3 (Right-hand drive version)

Fig 1: Driver Seat Control Unit Components Location - Model 447 With Code H16, SF1

Courtesy of MERCEDES-BENZ USA

Location

The control unit for the driver seat is located at the bottom of the driver seat frame. Depending on equipment installed, different control units are installed:

Driver seat heater/ventilation control unit (N32/3) (with CODE H16 (Seat heater for driver) and without CODE ZM3 (Right-hand drive vehicle version))
Driver seat heater/ventilation control unit (N32/4) (with CODE H16 (Seat heater for driver) and with CODE ZM3 (Right-hand drive vehicle version))
Driver seat adjustment control unit with memory (N32/5) (with code SF1 (Electrically adjustable luxury driver seat))

Task

The driver seat heater/ventilation control unit (N32/3) or driver seat heater/ventilation control unit (N32/4) has the following task:

Power supply for the seat heater of the driver and front passenger seat

The driver seat adjustment control unit with memory (N32/5) has the following tasks:

Power supply for the seat heater of the driver seat
Power supply for the driver seat lumbar support adjustment control unit (N32/23) (with CODE SE5 (Driver seat lumbar support))
Control of the seat adjustment
Saves memory settings

The tasks are subdivided as follows:

Reading in of signals
Evaluation of signals
Actuation of components

Reading in of signals

Signals are read in via the following connections:

Direct line
Interior CAN (CAN B)

Direct line

The following signals are read in via a direct line:

Driver seat fore/aft adjustment Hall sensor (M27/1b1) (with code SF1 (Electrically adjustable luxury driver seat))
Driver seat height adjustment Hall sensor (M27/2b1) (with code SF1 (Electrically adjustable luxury driver seat))
Driver seat inclination adjustment Hall sensor (M27/3b1) (with code SF1 (Electrically adjustable luxury driver seat))
Driver seat head restraint adjustment Hall sensor (M27/4b1) (with code SF1 (Electrically adjustable luxury driver seat))
Driver seat backrest inclination Hall sensor (M27/5b1) (with code SF1 (Electrically adjustable luxury driver seat))

Interior CAN (CAN B)

The following signals are read in via the interior CAN (CAN B):

Seat heater request
Seat adjustment request (with code SF1 (Electrically adjustable luxury driver seat))
Save or call up memory position request (with code SF1 (Electrically adjustable luxury driver seat))

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

Evaluation of signals

The signals that have been read in are evaluated by the integrated microprocessor and the corresponding components are then actuated.

Actuation of components

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

Direct line
Interior CAN (CAN B)

Direct line

The following components are actuated via a direct line:

Driver seat fore/aft adjustment seat adjustment motor (M27/1) (with code SF1 (Electrically adjustable luxury driver seat))
Driver seat height adjustment seat adjustment motor (M27/2) (with code SF1 (Electrically adjustable luxury driver seat))
Driver seat inclination adjustment seat adjustment motor (M27/3) (with code SF1 (Electrically adjustable luxury driver seat))
Driver seat head restraint adjustment seat adjustment motor (M27/4) (with code SF1 (Electrically adjustable luxury driver seat))
Driver seat backrest inclination seat adjustment motor (M27/5) (with code SF1 (Electrically adjustable luxury driver seat))
Driver seat lumbar support adjustment control unit (N32/23) (with code SE5 (Driver seat lumbar support) and with code SF1 (Electrically adjustable luxury driver seat))
Driver seat cushion heater pad (R13/1)
Driver seat backrest heater pad (R13/2)
Front passenger seat cushion heater pad (R13/3) (without code SF2 (Electrically adjustable front passenger seat))
Front passenger seat backrest heater pad (R13/4) (without code SF2 (Electrically adjustable front passenger seat))

Interior CAN (CAN-B)

The following signals are sent via the interior CAN (CAN B):

Seat heater status
Status of lumbar support (with code SE5 (Driver seat lumbar support) and with code SF1 (Electrically adjustable luxury driver seat))
Seat position status (with code SF1 (Electrically adjustable luxury driver seat))
Acknowledge tone request after memory position storage (with code SF1 (Electrically adjustable luxury driver seat))

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

Wiring diagram for seat adjustment, driver seat heater	Model 447.8 with code SF1 (Driver's seat electrically adjustable)	PE91.00-S-2105-97VVA
	Model 447.6/7 with code SF1 (Driver's seat electrically adjustable)	PE91.00-S-2105-97VVB
Wiring diagram of driver seat control unit	Model 448.8 with code SF1 (Driver's seat electrically adjustable)	PE91.29-S-2114-97VDA