Left front seat control unit, component description - GF91.29-P-5230LE

MODEL 216.3, 221.0 /1 as of model year 2009 /YoM 08 

Shown on model 221 model year 2009 / YoM 08 

Location 

The left front seat control unit is located on the seat cushion frame of the driver seat.

Task 

• Control of seat adjustment in accordance with the requests sent over the interior CAN (CAN B)
• Storage of memory settings for seat, steering column and outside mirrors (for right-hand drive vehicles memory settings for seat only)
• Seat belt comfort fit feature
• Control of lumbar support adjustment (without code (409) Left/right front multicontour seats and without code (432) Left and right dynamic multicontour seat)
• Control of seat heaters HS [SIH] (on model 221 with code (873) Right and left front seat heaters or code (401) Front comfort seats, incl. seat heating and seat ventilation and on model 216)
• Control of seat ventilation (with code (401) Front comfort seats, incl. seat heating and seat ventilation)
• Control of easy entry/exit (only left-hand drive vehicles on model 221 with code (275) Memory package for electrically adjustable front seats and model 216)
• Control of crash-active easy exit (only left-hand drive vehicles on model 221 with code (275) Memory package for electrically adjustable front seats and model 216)
• Control of memory function (left-hand drive vehicles on model 221 with code (275) Memory package for electrically adjustable front seats and model 216)
• Actuation of footwell illumination in rear (on model 221)
• Control of rear compartment access (EASY-ENTRY function) (model 216)
• Actuation of front passenger seat adjustment with PRE-SAFE (right-hand drive vehicles only)

These are grouped as follows:

• Reading in of sensors and signals 
• Evaluating input factors 
• Actuation of components 

Reading in of sensors and signals 

These input factors are read in via the following connections:

• Direct line 
• Interior CAN 

Direct line 

• Circuit 30
• Tml. 31

The following sensors are read in via direct lines:

• Hall sensors of seat adjustment motors
• Driver lumbar support regulator control unit (N32/23) (without code (409) Left/right front multicontour seats and without code (432) Left and right dynamic multicontour seat)
• Vehicle-sensitive belt lock sensor (A60) (model 216)
• Left front seat backrest angle microswitch (S91/1) (model 216)

The left front seat control unit serves as a contact point for:

• Left front seat ventilation blower regulator (N29/5) (with code (401) Front comfort seats, incl. seat heating and seat ventilation)
• Driver lumbar support regulator control unit (N32/23) (without code (409) Left/right front multicontour seats and without code (432) Left and right dynamic multicontour seat)
• Left front multicontour backrest control unit (N32/15) (with code (409) Left/right front multicontour seat)
• Left front dynamic seat control unit (N32/19) (with code (432) Left/right front multicontour seat)

Interior CAN 

• Left front seat operation switch group (S22) by the left front door control unit (N69/1) (model 221) or left door control unit (N69/1) (model 216)
• Steering column status by the front SAM control unit with fuse and relay module (N10/1) (left-hand drive vehicles)
• Lumbar support specified setting by the central gateway control unit (N93)
• Brightness as well as switch-on and switch-off signals for the footwell illumination in the rear by the overhead control panel control unit (N70)
• Terminal status from EIS [EZS] control unit (N73)

Evaluation of input factors 

The input factors that have been read in are evaluated by the left front seat control unit, the actuators are then actuated. The actuation of the motors for the seat adjustment takes place via integrated relays.

Actuation of components 

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

• Direct line 
• Interior CAN 

Direct line 

The following components are actuated via direct lines:

• Left rear footwell lamp (E17/18) (on model 221)
• Left front seat fore/aft adjustment motor (M27/1)
• left front head restraint motor (M27/4)
• Left front backrest angle adjustment motor (M27/5)
• left front seat cushion fore/aft motor (M27/8)
• left front seat cushion inclination motor (M27/9)
• left front seat height adjustment motor (M27/10)
• Left front seat belt comfort solenoid (K18/4)
• Left front seat belt lock relay (K18/2) (on model 216)
• Left front seat heater pad (R13/1) and left front backrest heater pad (R13/2) (on model 221 with code (873) Left and right front seat heater or code (401) Front comfort seats including seat heating and seat ventilation and on model 216)
• Left front seat ventilation blower regulator (N29/5) (with code (401) Front comfort seats, incl. seat heating and seat ventilation)
• Driver lumbar support regulator control unit (N32/23) (without code (409) Left/right front multicontour seats and without code (432) Left and right dynamic multicontour seat)
• Power supply for left front multicontour backrest (N32/15) (with code (409) Left/right front multicontour seat) or Left front dynamic seat control unit (N32/19) (with code (432) Left/right front multicontour seat)

Interior CAN 

• Signals for actuating memory positions of outside mirror to left front door control unit (model 221) or left door control unit (model 216) (only left-hand drive vehicle) or right front door control unit (model 221) or right door control unit (N69/2) (model 216) (only right-hand drive vehicle)
• Signals for actuating memory positions of steering column to front SAM control unit with fuse and relay module (only left-hand drive vehicle)
• Signals for adjusting stored pressures to corresponding memory positions for dynamic multicontour seat to left front dynamic seat control unit (with code (432) Left/right front multicontour seat).
• Signals for adjusting stored pressures to corresponding memory positions to left front multicontour backrest control unit (with code (409) Left/right front multicontour seat)
• Signal for output of acknowledgment tone of memory position to instrument cluster (A1) via central gateway control unit (left-hand drive vehicles on model 221 with code (275) Memory package for electrically adjustable front seats and model 216)

Variants 

The following variants are available for the hardware of the left front seat control unit.

• Left front seat control unit, model 216
• Left front seat control unit, model 221

The country or left-hand drive vehicle/right hand drive vehicle allocation is software coded.

	Wiring diagram left front seat control unit	MODEL 221 control unit N32/1	PE91.29-P-2101-99SAA
		MODEL 216 control unit N32/1	PE91.29-P-2101-99CAA