Front Door Latch: Service and Repair

51 21 090 - Removing and installing/replacing door lock in left or right front door





Special tools required:
- 51 2 190 51 2 190 Door Lock Tensioner





Necessary preliminary tasks:
- Close window in front door
- Remove function carrier Removing and Installing/Replacing Function Carrier on Left or Right Front Door





Feed out Bowden cable on carrier.
1. Pull out Bowden cable towards bottom.
2. Pull out cable at side.
3. Clip (Bowden cable with blue sealing cap only)





Important!
Do not damage door lock seal when removing.

Unclip lock knob control rod (1).

Release screws (2).
Remove door lock from inside with drive facing forwards (twist out).

Important!
To avoid leakage and electrical malfunction, pull door lock with special tool 51 2 190 51 2 190 Door Lock Tensioner into corner (3), refer to next work step.
Door lock must be at zero current with Soft Close Automatic (risk of damage).





Installation:
- Install door lock and insert screws (1), do not tighten down.
- Slide special tool 51 2 190 51 2 190 Door Lock Tensioner into opened rotary latch until latch engages in first stage.





Installation:
- Pretension door lock (1) with knurled screw (2) until special tool 51 2 190 51 2 190 Door Lock Tensioner just contacts corner points (3).

Important!
To tension door lock (1), it is only permitted to turn knurled screw (2) by a further 1 to 1.5 turns (max.) (risk of damage).
Door lock seal must be uniformly positioned (water ingress).

- Tighten down door lock screws (1), tightening torque 51 21 1AZ [1][2]Specifications.





Note on installation (driver's side only):
Feed paddle (1) into bushing (2) from below.





Installation:
Bowden cable (1) and fiber optics cable (2) must be routed below bridge (3).
No fiber optics cables are fitted from build date 04/04.





Installation:
Seal (1) must not be damaged.





Replacement:
Feed out Bowden cable:
1. Pull out Bowden cable sleeve.
2. Turn Bowden cable and pull out.