Front seats

Facelift front seat (crosscut).

Front seat adjustment

The seat adjustment switches are located on the front doors.

• (1) Head restraint height
• (2) Seat height
• (3) Seat cushion tilt
• (4) Seat cushion depth
• (5) Seat fore and aft adjustment
• (6) Seat backrest tilt

To adjust the seat switch on ignition or open the respective door.

Seat fore and aft adjustment: Press the switch forward or backward in the direction of arrow (5). Adjust seat to a comfortable seating position that still allows you to reach the accelerator/brake pedal safely. The position should be as far to the rear as possible, consistent with ability to properly operate controls.

Seat cushion tilt: Press the switch up or down in the direction of arrow (3) until your upper legs are lightly supported.

Seat cushion depth: Press the switch forward or backward in the direction of arrow (4) until your legs are supported comfortably.

Seat backrest tilt: Press the switch forward or backward in the direction of arrow (6) until your arms are slightly angled when holding the steering wheel.

Seat height: Press the switch up or down in the direction of arrow (2).

Head restraint height: Press the switch up or down in the direction of arrow (1).

Head restraint tilt: Manually adjust the angle of the head restraint. Push or pull on the lower edge of the head restraint cushion.

Unoccupied front passenger seat automatic adjusting: The feature below is deactivated at the factory. If you wish to have it activated, use DAS. The front passenger seat head restraint automatically lowers after a few seconds when the front passenger seat is not occupied. This improves the driver's outward view as well as the forward view from the rear passenger compartment. When the front passenger seat is occupied again, the front passenger seat head restraint returns to the last set position within a few seconds. If the front passenger seat was moved fore or aft while not being occupied, the front passenger seat head restraint returns to a position that corresponds best with the seat’s axial position when the seat is occupied again.

Remove/install front seat backrest seat-back lining

1 - Bolts 2 - Seat-back lining

1. Slide the front seat forwards with the longitudinal adjustment mechanism
2. Slide backrest forwards with the inclination adjustment mechanism
3. Unscrew screws (1)
4. Pull seat-back lining (2) down and take off. Installation: slide seat-back lining into top of backrest.
5. Install in the reverse order

Seat backrest lining screw.

Backrest lining of facelift front seat.

Front seat with backrest lining removed.

Remove and install headrest guide on front seat

1 - Headrest guide 2 - Head restraint 3 - Front seat backrest M27m4 - Head restraint motor, raise and lower M28m4 - Head restraint motor, raise and lower

Remove:

1. Remove head restraint (2)
2. Remove tensioning element (seat-back lining) from front seat backrest
3. Remove head restraint raise/lower motor (M27m4/M28m4). Push motor to right first and then remove downwards.
4. Release catch at head restraint guide (1) using screwdriver. Push back catch (arrow) at head restraint guide (1) using screwdriver and pull head restraint (1) out upwards.
5. Release catch at head restraint guide (1) using pulling hook. Insert pulling hook into top of head restraint guide (1), push back catch and pull out head restraint upwards.

Install:

1. Insert head restraint guide (1) into backrest frame of front seat backrest (3). Do not damage backrest upholstery. Catch (arrow) must point towards rear.
2. Engage head restraint guide (1) in backrest frame of front seat backrest (3)
3. Install head restraint raise/lower motor (M27m4/M28m4). Insert motor facing upwards and then push to left until it engages in backrest frame.
4. Fit seat-back lining to front seat backrest (3)
5. Install head restraint (2)

Error Code	Generated By	Description
B1203	ESA-FL - Electronic seat adjustment front left	Hall sensor of component M27m4 (Head restraint raise/lower motor) is faulty

Facelift head restraint motor A2209700026 fits both sides.

Note: when installing new motor the new motor may be need to be moved manually to the position of the old motor, otherwise it may be encountered that motor is not able to move the full distance.

Facelift head restraint motor (A2209700026) removed.

Remove/install front seat (as of 01/09/2002)

1 - Head restraint 2 - Front seat 3 - Cover 4 - Belt end fitting 5 - Screw 6 - Grommet 7 - Retaining clamp 8 - Pneumatic line plug coupling 9 - Screw 10 - Seat rail final cover 11 - Cover N32/1 - Left front seat adjustment control unit with memory N32/2 - Right front seat adjustment control unit with memory X28/34 - Driver seat separation point buckle emergency tensioning retractor connector (2-pin) X28/35 - Front passenger seat separation point buckle emergency tensioning retractor connector (2-pin)

1. Switch off ignition, remove ignition key (vehicles without KEYLESS-GO, code 889).
2. Switch off engine, remove transmitter key from vehicle (with KEYLESS-GO, code 889). Keep transmitter key out of transmitter range.
3. Remove head restraint (1)
4. Adjust front seat (2) to front. Move front and rear seat cushions all the way up. Move backrest into upright position.
5. Remove cover (3) at rear side paneling
6. Remove screw/bolt (5) at belt end fitting (4). Installation: When screwing on, ensure that belt end fitting (4) remains mobile.
7. Remove rear screws/bolts (9) from seat rails. Remove cover (11) from seat rail.
8. Turn retaining clamp (7) at Bowden cable in direction of transmission tunnel and remove
9. Unhook grommet (6) with Bowden cable from bracket
10. Position front seat (2) to rear
11. Remove front screw/bolt (9) from seat rails. Remove cover (11) from seat rail.
12. Pry off pneumatic line plug coupling (8) with open end wrench, size 7. Slightly incline seat toward rear in vehicle.
13. Detach connecting coupling (see arrow) from front seat adjustment control unit with memory, left (N32/1), right (N32/2). Slightly incline seat toward rear in vehicle.
14. Disconnect 2-pin driver seat connecting point buckle emergency tensioning retractor connector (X28/34), 2-pin front passenger seat connecting point buckle emergency tensioning retractor connector (X28/35). Slightly incline seat toward rear in vehicle.
15. Remove seat rail final cover (10) from seat rails
16. Lift front seat (2) and remove
17. Install in the reverse order
18. Check function of seat adjustment mechanism

Torque specifications:

• Bolt to seat runner: 45 Nm
• Screw on belt end fitting: 30 Nm

Remove/install front seat (up to 31/08/2002)

1 - Head restraint 2 - Front seat 3 - Cover 4 - Belt end fitting 5 - Screw 6 - Cover 7 - Screw

8 - Pneumatic line 9 - Retaining clamp 10 - Seat adjustment mechanism X55/3 - Left front seat contacting strip X55/4 - Right front seat contacting strip

1. Remove head restraint (1)
2. Adjust front seat (2) to front
3. Remove cover (3) above belt end fitting (4)
4. Remove bolt (5) from seat belt end fitting (4)
5. Remove screws (7) at the back of the seat rails
6. Remove covers (6) at rear of seat rails
7. Position front seat (2) to rear
8. Remove screws (7) at the front of the seat rails
9. Remove covers (6) at front of seat rails
10. Detach plug connection from pneumatic line (8) and left front seat connector block (X55/3) and right front seat connector block (X55/4) from front seat cushion. Disconnect plug connection on pneumatic line (8) with 7 mm open end wrench.
11. Detach retaining clamp (9) for Bowden cable seat belt height adjustment at seat adjustment mechanism (10) in direction of arrow
12. Lift front seat (2) and remove
13. Install in the reverse order

Torque specification:

• Bolt to seat runner: 50 Nm (up to 30/11/2001), 45 Nm (as of 01/12/2001)
• Screw on belt end fitting: 30 Nm

Remove/install front seat backrest (as of 01/09/2002)

1 - Front seat backrest 2 - Stowage compartment 3 - Left side paneling 4 - Bolt 5 - Bolt 6 - Pneumatic line 7 - Seatbelt buckle 8 - Bolt 9 - Cover on seat belt buckle 11 - Bottom side paneling 12 - Cover on the belt end fitting N32/15 - Left front multicontour backrest control unit N32/16 - Right front multicontour backrest control unit

10 - Electrical line 13 - Backrest fitting 14 - Bolts N32/1 - Left front seat adjustment control unit with memory N32/2 - Right front seat adjustment control unit with memory

1. Remove front seat
2. Open flap on stowage compartment (2)
   1. Unclip stowage compartment (2)
   2. Remove fire extinguisher (for fire extinguisher code 682)
3. Remove bolts (4, 2 pieces) on the left side paneling (3)
4. Unscrew and remove bolt (see arrow) on the belt end fitting cover (12)
5. Unscrew bolt (5) on the left side paneling (3) (see enlarged detail)
6. Detach left side paneling (3) in direction of travel
7. Unclip lower side paneling (11) in the direction of the arrow (for the multicontour backrest for the driver seat code 404b and front passenger seat code 405b).
8. Remove multicontour backrest control unit on front seat (for the multicontour backrest for the driver seat code 404b and front passenger seat code 405b).
9. Remove bolt (see arrow) and bolt (8) on seat belt buckle (9) cover
10. Unclip retaining lug (see enlarged detail) and remove seat belt buckle (9) cover
11. Expose and detach electrical line (10) from the front seat backrest (1) to the front seat adjustment control unit with memory, on the left (N32/1), right (N32/2). Installation: Ensure that routing is chafing-free.
12. Remove bolt (14, 2 pieces) on the right and left side from the backrest fitting (13)
13. Remove front seat backrest (1) from seat adjustment mechanism
14. Install in the reverse order
15. Perform function test for the seatrest function

Torque specifications:

• Bolt on backrest fitting: 35 Nm

Remove/install front seat backrest (up to 31/08/2002)

1 - Trim 2 - Trim 3 - Seatbelt buckle 4 - Screw 5 - Screw 6 - Backrest fitting N32/1 - Left front seat adjustment control unit with memory N32/2 - Right front seat adjustment control unit with memory

1. Remove front seat
2. Remove screw (arrow) on paneling (1)
3. Remove trim panel (1)
4. Remove bolt (4) and remove seat belt buckle (3)
5. Remove screw (arrow) on paneling (2)
6. Remove trim panel (2)
   1. Separate pneumatic line connector for lumbar support air cushion
   2. Remove multicontour backrest control unit from front seat (on vehicles with driver seat multicontour backrest, code 404b and passenger seat, code 405b).
7. Disconnect backrest and head restraint adjustment connector from left front seat adjustment control unit with memory (N32/1) and right front seat adjustment control unit with memory (N32/2)
8. Unscrew bolt (5, 2 each) from left and right backrest fitting (6)
9. Remove front seat backrest from the seat adjustment mechanism
10. Install in the reverse order

Torque specifications:

• Bolt at backrest fitting: 35 Nm (up to 30/11/2001 and as of 01/12/2001)
• Screw/nut on front seat belt buckle: 30 Nm

Remove/install driver seat cushion (as of 01/09/2002)

1 - Seat cushion 2 - Stowage compartment 3 - Left side paneling 4 - Screw 5 - Screw 11 - Bottom side paneling 12 - Stowage compartment retaining frame 13 - Paneling on belt end fitting N32/15 - Left front multicontour backrest control unit N32/16 - Right front multicontour backrest control unit S108 - Right front multicontour backrest switch group S109 - Left front multicontour backrest switch group

1 - Seat cushion 7 - Seat adjustment mechanism 14 - Screw bl - Blue connector for fan motor N32/1 - Left front seat adjustment control unit with memory N32/2 - Right front seat adjustment control unit with memory

1. Remove front seat. Move seat cushion all the way up and to center position so that rear bolt (14) on belt buckle is accessible.
2. Open flap in stowage compartment (2)
   1. Unclip stowage compartment (2)
   2. Remove fire extinguisher (with fire extinguisher, code 682).
3. Unscrew bolts (4, 2 each) from left side paneling (3)
4. Unscrew bolt (see arrow) at rear of paneling (13) on belt end fitting and remove
5. Unscrew bolt (5) from left side paneling (3)
6. Remove left side paneling (3) in direction of travel
7. Unclip bottom side paneling (11) in direction of arrow (with driver seat multicontour backrest, code 404b, passenger seat, code 405b).
8. Remove pneumatic lines from lumbar support control valve
9. Remove connector coupling from left front multicontour backrest switch group (S109), right front multicontour backrest switch group (S108) (on driver seat multicontour backrest code 404b, passenger seat code 405b or left dynamic seat including multicontour seat code 433, right code 434).
10. Remove omega clip (see arrow) from seat cushion frame
11. Remove connector coupling from dynamic seat switch (on left dynamic seat incl. multicontour seat code 433, right code 434).
12. Remove multicontour backrest control unit from front seat (with driver seat multicontour backrest, code 404b, passenger seat, code 405b).
13. Unscrew stowage compartment retaining frame (12) from cushion frame
14. Unscrew bolt (14, 2 each) and slide seat cushion (1) on seat adjustment mechanism (7) toward front. Do not yet remove seat cushion (1) from seat adjustment mechanism.
15. Disconnect blue connector on fan motor (bl) (for code (401a) front comfort seat, incl. seat heating and seat ventilation).
16. Remove coupling for seat cushion heater (see arrow in magnifying glass) from left front seat adjustment control unit with memory (N32/1), right front seat adjustment control unit with memory (N32/2) (for front comfort seats, incl. seat heating and seat ventilation vehicles, code 401a or right and left front seat heaters or code 873).
17. Remove seat cushion (1) from seat adjustment mechanism (7)
18. Install in the reverse order
19. Check seat adjustment for proper function

Torque specifications:

• Bolt, seat cushion to seat adjustment mechanism: 15 Nm

Remove/install driver seat cushion (up to 31/08/2002)

1 - Screw 2 - Trim 3 - Trim 4 - Trim 5 - Cap 6 - Bolts N32/1 - Left front seat adjustment control unit with memory N32/2 - Right seat adjustment control unit with memory

7 - Seat adjustment mechanism 8 - Seat cushion 9 - Screw 10 - Trim 11 - Bracket 12 - Bolts 13 - Bolts

1. Remove front seat
2. Remove screw (1) and remove paneling (2)
3. Open cap (5) and remove fire extinguisher (with fire extinguisher, code 682).
4. Remove screws (6, arrows) and remove paneling (4) and cap (5)
5. Pull off paneling (3) in direction of arrow. Ensure that retaining lugs are not damaged.
6. Disconnect connector from seat cushion heater on left front seat adjustment control unit with memory (N32/1) and right front seat adjustment control unit with memory (N32/2).
7. Remove multicontour backrest control unit from front seat (with driver seat multicontour backrest, code 404b, passenger seat, code 405b).
8. Remove screw (9) and remove paneling (10)
9. Remove screws (13) and remove seat cushion (8) forwards from the seat adjustment mechanism
10. Remove screws (12, arrows) from the seat cushion (8) and remove bracket (11) from the seat cushion (8)
11. Install in the reverse order

Torque specifications:

• Bolt, seat cushion to seat adjustment mechanism: 15 Nm (up to 30/11/2001 and as of 01/12/2001)

Remove/install seat belt (front seat) as of 01/09/2002

1 - Upper belt guide fitting 2 - Nut 3 - Cover 4 - Belt end fitting 5 - Bolt 6 - Bowden cable 7 - Bolt 8 - Torx screws A76 - Left front reversible emergency tensioning retractor [RevETR-LF] A76/1 - Right front reversible emergency tensioning retractor [RevETR-RF]

1. Move front seat as far forward as possible with backrest upright
2. Switch ignition off, withdraw ignition key
3. Switch engine off, remove transmitter key from vehicle. With KEYLESS-GO code 889 keep transmitter key outside transmission range.
4. Remove paneling on B-pillar
5. Remove cover (3) of belt end fitting (4) and undo screw (5)
6. Unscrew screw (2) from seat belt guide bracket (1)
7. Unhook Bowden cable (6) on cover plate (see magnifying glass at bottom right)
8. Undo TORX screw (8, 4 pieces) on cover plate. Installation: Tighten screw (7) to torque rating.
9. Undo screw (7) from cover plate. Installation: Tighten screw (7) finger-tight only to cover plate.
10. Detach 6-pin coupling and 2-pin coupling (see arrows) of left front reversible emergency tensioning retractor (A76), and right front reversible emergency tensioning retractor
11. (A76/1) Remove left front reversible emergency tensioning retractor (A76), and left front reversible emergency tensioning retractor (A76/1). Installation: Note different version (left/right) of seat belt emergency tensioning retractor and correct seating in cover plate. Noises from the automatic belt reel when rolling up belt are normal. The only available response to negative customer feedback regarding unacceptable noise levels is to replace the seat belt assembly with emergency tensioning retractor in its entirety. On no account should oil or grease be used to help eliminate noise. Automatic belt retractors that have been opened are no longer under warranty!
12. Install in the reverse order
13. Carry out diagnosis

Torque specification:

• Belt end fitting screw: 30 Nm
• Screw/nut on front seat belt guide bracket: 30 Nm
• Screw on front automatic belt reel: 30 Nm
• Bolt, emergency tensioning retractor cover plate to B-pillar: 10 Nm

Right front reversible emergency tensioning retractor unscrewed.

Remove/install seat belt (front seat) up to 31/08/2002

1 - Belt end fitting 2 - Upper belt guide fitting 3 - Automatic belt retractor R12/1 - Driver ETR [GUS] ignition squib R12/2 - Passenger ETR [GUS] ignition squib

2 - Upper belt guide fitting 3 - Automatic belt retractor 4 - Bolt 5 - Nut 6 - Clutch R12/1 - Driver ETR [GUS] ignition squib R12/2 - Passenger ETR [GUS] ignition squib

1. Move front seat as far forward as possible with backrest upright
2. Switch ignition off, withdraw ignition key
3. Switch engine off, remove transmitter key from vehicle. With KEYLESS-GO code 889 keep transmitter key outside transmission range.
4. Remove paneling on B-pillar
5. Remove cover of belt end fitting (1) and undo screw
6. Unscrew nut (5) from seat belt guide bracket (2)
7. Release coupling on driver ETR [GUS] ignition squib (R12/1), passenger-side ETR [GUS] ignition squib (R12/2) and coupling (6)
8. Remove screw (4) at automatic seat belt retractor (3)
9. Remove automatic belt reel (3). Installation: Note different version (left/right) of seat belt emergency tensioning retractor and correct seating in catch. Noises from the automatic belt reel when rolling up belt are normal. The only available response to negative customer feedback regarding unacceptable noise levels is to replace the seat belt assembly with emergency tensioning retractor in its entirety. On no account should oil or grease be used to help eliminate noise. Automatic belt retractors that have been opened are no longer under warranty! If the seat belt with emergency tensioning retractor has been replaced, the defective unit must be disposed of properly.
10. Install in the reverse order
11. Carry out diagnosis

Torque specification:

• Belt end fitting screw: 30 Nm
• Screw/nut on front seat belt guide bracket: 30 Nm
• Screw on front automatic belt reel: 30 Nm

Seat belt height adjustment mechanism (front seat) removal and installation

1 - Belt height adjuster 2 - Bolt 3 - Bowden cable 4 - Nut

1. Remove front seat
2. Remove paneling on B-pillar
3. Unclip Bowden cable (3) using Omega clip
4. Unclip Bowden cable (3) from deflection in cable duct. Lift floor lining at left front until the deflection for the Bowden cable (3) in the cable duct can be easily accessed.
5. Disassemble the Bowden cable (3) up to the belt height adjuster (1)
6. Undo nut from seat belt guide bracket (4)
7. Undo screw (2, 2 pieces) on belt height adjuster (1)
8. Install in the reverse order

Torque specification:

• Screw/nut on front seat belt guide bracket: 30 Nm
• Screw on front automatic belt height adjuster: 25 Nm

Retrofit front seat height adapter

1 - Spacer 2 - Foam rubber 3 - Covers 4 - Bolts 5 - Front seat

1. Remove bolts (4, 4 pieces) on the front and rear seat rail
2. Raise front seat frame, place spacers (1) (part number A2209101736) on the right and left as well as at the front and rear under the under the seat rails and fasten with the bolts contained in the accessories. Do not damage covers (3).
3. Clamp foamed material (2) in each case in front of and behind the spacer (1) under the covers (3) of the seat rails
4. Check seat adjustment for proper function
5. If the package changes, supplement the code or designation of the relevant special equipment on the vehicle data card

Torque specifications:

• Bolt to seat runner: 50 Nm (up to 30/11/2001)

DIY How to replace front lumbar supports

• http://www.benzworld.org/forums/w220-s-class/2395441-how-replace-your-front-lumbar-supports.html