190e boot locking problem

stuarth

Active Member
Joined
Sep 26, 2004
Messages
40
Reaction score
0
WHen I unlock the driver's door, the boot can sometimes be opened and sometimes not. There is an audible movement there but it remains locked quite often. Another issue is that when I remove the key from the drivers door after unlocking, the whole car then relocks itself.
This could be two separate issues or be connected in some way but unlcoking the boot is the bigger of the two.
I have not dismantled the boot lock and actuator yet since i am not sure what to avoid when I do so - is it simple or are there impossibly fiddly things to reconnect?
Any clues?

thanks
 

wireman

Senior Member
Joined
Sep 20, 2005
Messages
2,632
Reaction score
3
Location
lancashire
Your Mercedes
nice 201 2.5D 1993 & very nice 129 SL500 1994
The pneumatic actuator that operates on one your locks is probably the root cause.

Does the system hiss from near any of the locks whilst the central locking is in operation? if so its that lock at fault.

The door locks are accessed by removing the door card.

If its the boot lock, remove the trim below the boot lid, take out the boot lock carefully observing the assembly as you do (you will want to put it back in) The actuator is fixed to the back panel aside the lock held by a few small screws, remove them and just disconnect its rod from the lock and the yellow pipe to remove it from the car.

The diaphragm inside the actuator splits and leaks either the vacuum that unlocks your doors or compressed air that locks them, the resulting behavior is that some times some of the locks dont function fully leaving some locked and some not locked, if either front door is not quite unlocked by its actuator the switch attached to the door lock/key signals to the pump that a door has been locked and the pump tries to lock all the doors again (or the reverse if it has happened when the doors were unlocked).

If the system is leaky the pump (under the rear seat) tends to run on audibly for up to 20 seconds after the locks have been set.

I have had this fault on both 201 and 190 models. The door and boot actuators have the same contruction but the attached rods differ from door to door. The fuel flap actuator also fails leaky but differs totaly from the door type.
The system is manufactured by Hella and some Audi models have similar parts.

Listen for the leak and replace the actuator.
 

Dec

Senior Member
Joined
Nov 30, 2005
Messages
3,300
Reaction score
4
Location
Ireland.
Your Mercedes
W202
This is a W202, C class boot lock, yours will not be the same but will give you an idea on what to expect.
If you remove the lock and detach the vacuum line then suck or blow (hard) on the vacuum chamber (white bit) the lock should lock or unlock, a click/noise will be heard.

Put your finger on the detached vacuum line and have someone lock unlock the car, you should feel a suck/blow, hold the boot door pin in so as not to trigger the alarm, if fitted.

Regarding the driver’s door, that could be a separate fault, you could remove the door handle keyhole section, without removing the door card and spray trough the hole where the lock key hole was with WD40.

Dec
Edit...See also http://forums.mercedesclub.org.uk/showthread.php?t=51586
 
Last edited:
Top Bottom