W163 facelift (2004) rear door lock fault

[MawfTech]

Hi,

I've gt a W163 facelift 04 reg with a faulty rear door lock (it won't central lock). Had the inner door cover off today but can't see how to service the lock, I can't physically get to it to see if it's a faulty solenoid, dodgy wiring or something else . There's no mechanical movement when locking/unlocking. Physically, the lock functions normally manually just not by the solenoid.

Anyone got any information or help on servicing the rear door lock mechanism i.e. how to remove the solenoid for checking/replacement?

Cheers,

MawfTech

 

[BlackC55]

Check you have voltage there first when locking.

The lock is unserviceable and it is quite likely that it will need to be replaced.

 

[MawfTech]

Thanks. I can check power at the door block (looks like a glorified scart connector). Can you tell me which pins service the solenoid?

If it were to be replaced, what's the likely cost to get this done. I'm assuming it's a garage job so expect it's pretty hefty.

Anyone know of any likely places in Essex that are 'reasonable' ?

MawfTech

 

[230K]

Hi

There is a little plastic rod that actuates off the solenoid, the rod breaks or the heads breaks off it. You can drill the rod and put a self tapper in it to replicate the end of the rod with a bit of tidy work.

If that is the problem then it will become apparent when you see it

230K

 

[lynall]

Hi

There is a little plastic rod that actuates off the solenoid, the rod breaks or the heads breaks off it. You can drill the rod and put a self tapper in it to replicate the end of the rod with a bit of tidy work.

If that is the problem then it will become apparent when you see it

230K

Thats exactly what i did with wifes Ml320, piece of piss just fiddly and save new solenoid iirc over £100.

What i did was drill the rod, screw in self tapper, cut off self tapper head drill other half of the rod and screw them together.



Lynall

 

[MawfTech]

Thanks guys.

Just one question though, how the heck do you get to it? I've removed the inner panel, peeled back the foam pad, removed the plate that's just beyond the glass guide but for the life of me, cannot reach the locking mechanism still. I'm worried if I unscrew the two torx bolts holding the lock, I'll either drop it, never to get it back in or not be able to reattach it to the outer handle. Is there an easier way to do this or some diagrams somewhere to help? Feel pretty sure that if I can dismantle the mechanism, I can repair the unit either with an OEM solenoid or as you guys suggest by mending the rod (if its broken - have to say though, I cannot hear anything actuating in the door so could still be electrical fault).

MawfTech

 

[lynall]

Its not the lock its the electircal solenoid that attachs to the lock.
It will have a couple of wires going to it.
Worth joining the yank sites (free) mbworld and benzworld.



Lynall

 

[MawfTech]

Thanks Lynall,

Sorry, yes I know it's a solenoid. What I was saying is that I can't see how to get to it, it's right up in the far reaches of the rear door by the lock. With no other nuts or bolts that I can see, the only means of getting to the solenoid would be to unmount the whole lock which I'm then presuming has the solenoid attached. I can then service it hopefully. It's just that I physically cannot reach the unit with my hand as there's the window guide in the way. I cannot even reach the block that's plugged into the bottom of the lock unit with four wires presumably for the door close detector and the solenoid.

Anyone know if there is a better way to get to the solenoid on the rear door of a W163 facelift?

MawfTech

 

[230K]

Hi

I was talking about the rear door as in the tailgate or the boot. I have just realised that the OP is possibly talking about one of the rear side doors seeing as he mentions window guide?????? My advice does not apply to a side rear door, it only applies to the tailgate/boot whatever you wnat to call it.

230K

 

[MawfTech]

Oops, sorry. Yes, rear left passenger door to be precise. It's erm~ 'tricky' shall we say to service.

Anyone got any ideas?

 

[lynall]

No but like Brian i thought you were talking about the back door.

I saw these earlier but though they are no good as you wanted rear door info.

See here http://www.benzworld.org/forums/w163-m-class/1417771-diy-thread-collection-2.html benzworld you will have to join to get to the pdf files, think they are for front doors (a doors a door) but looks liks a lot of gear has to come off to get at the actuator.


Lynall

 

[MawfTech]

Lynall, thanks.

That thread in Benzworld (yep, I'm a member there too) is probably about as close as I can get. The rear door is slight different as it has two cables one for the button and the other for the inner door handle. It's also more difficult to get to as it's curved around the wheel arch so the lock is in the top of this curve. I'll try and figure out how to get the external door handle on and off before tackling this (can't seem to open the thread link for that but will search and no doubt find it on the forum) and it looks like the window guide that was in my way is riveted which is easy to remove and put back now I know.

I think there's every chance I will be able to repair or replace the solenoid if I can remove the lock mechanism. Good chance that I could also pick up a good-un at the local scrappy too.

Cheers guys.....wish me luck.

MawfTech

 

[lynall]

Its in the w163 how to section, easy to find as most of the old ones seem to have dissapeared.
Dont forget some pics and you can do your own how to.



Lynall

 

[MawfTech]

Thanks again Lynall. Now all I've got to do is get a 150mm long number 4 hex key to undo the outer door lever.

MawfTech

 

[MawfTech]

Well I tried to attack that lock. Unfortunately, the window guide doesn't simply unclip or have drill-out pop-rivets like the front windows so it seems pretty tricky still on how to actually get to the lock. Sadly, I removed the outer handle following instructions and could see more of the lock. When I put the handle back to try again next day, it went 'click' and now doesn't work. To cap it off, I had the child-lock set so I now can't open the door at all . So now it's gone into a local Merc specialist to get sorted. Reckon I'm probably in for £400+ (can you hear my sigh!)

I'm asking for any parts that are replaced to be left with the car. Hopefully I can figure out exactly what went wrong i the first place and can give some guidance for others that face similar probs.

Matt

 

[lynall]

Matt sorry to hear that, but for future reference whenever i have stripped or done any door work before shutting it i use a screwdriver in the catch to trip and set the catch then make sure it releases on the handle before shutting the door as there is nothing worse than clunk oh crap.



Lynall

 

[MawfTech]

Thanks Lynall,

Must say, after that infamous 'clunk' there were quite a few more colourful metaphors than just the 'oh crap'.

Had a call today from the garage (PMW Ltd in Chelmsford) and it's looking like £250 + VAT so maybe not so bad after all. From what I could see, the lock alone was going to sting me for £150+ from Mercedes and I know it probably had dodgy motor/solenoid anyway.

I've asked for the old locking mechanism back so I can examine what the original fault was and maybe figure out ways to help people out on this forum with similar problems in the future. Will also ask the obvious question - 'how the heck do you get to the lock to get it out'

One word of advise; if working on rear door locks, make sure to SWITCH OFF CHILD LOCKS!

Matt

 

[crawfmac]

m163 Rear Door Lock

Hi,
Just had same problem. How did you get on? I also broke a few door panel clips as well in atempt to see what was wrong....

 

[MawfTech]

Hi CrawfMac,

In the end, I took the car into PMW of Chelmsford who fitted a new lock. They also had to fit a new block to the door frame because it had distorted slightly making the door difficult to open.

I have the old lock unit they took off and it's quite a poor construction with many plastic parts that could distort or break including the infamous rod that connects the solenoid to the lock.

I just had the drvers door lock fail too with the 'machine-gun' issue. This happened when the door button wouldn't rise fully. I put the key in the outer lock and as I turned the key, I caught the button on the key that locks and 'clunk' followed by some more of those metaphores . Then everytime I used the plip, 'machine gun' rapid locking and he drivers door remaining unlocked. PMW replaced that one (£300) and all is well again. To me, this is clearly a design flaw.

Matt