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

MODEL 221.0 /1, 216.3 up to Model Year 8 

Location 

The left front seat control unit is located on the seat cushion frame of the driver seat (1).

Tasks 

The left front seat control unit has the following tasks:

• Actuation of the seat adjustment
• Actuation of 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 heated seats 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 memory function (on model 221 with code (275) Memory package (driver seat, steering column, mirrors) and on model 216)
• Control of easy entry/exit feature (on model 221 with code (275) Memory package (driver seat, steering column, mirrors) and on model 216)
• Actuation of footwell illumination in rear (on model 221)

Discrete outputs 

Voltage supply for the following components:

• 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 heated cushion (R13/1) (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)
• Left front backrest heated cushion (R13/2) (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)
• Left front seat cushion ventilation motor group (M18/9) (with code (401) Front comfort seats, incl. seat heating and seat ventilation)
• Left front seat backrest ventilation motor group (M18/10) (with code (401) Front comfort seats, incl. seat heating and seat ventilation)

Discrete inputs 

• Circuit 30
• Circuit 31
• Hall sensors of the motors (M27/1, M27/4, M27/5, M27/8, M27/9 and M27/10)
• 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 seatbelt lock sensor (A60) (on model 216)
• Left front seat backrest angle microswitch (S91/1) (on 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 (432) Left and right dynamic multicontour seat)

CAN signals 

The left front seat control unit is an interior CAN participant.