W169 A150 2008. Rear passenger door won’t stay locked with central locking

[Stuw2008]

Hi all,

I’m new here and am hoping for some top tips for this. I have an A150 2008 petrol manual that’s got an issue with door locking. I’ve read about similar sounding issues with this car but it’s not quite the same.

Only affects NSR passenger door. When central locking used to lock car all the door lock buttons drop down but then this door pops back up. Only once. No bouncing. It’s as if it is free to return up. If I’m in the car and hold it down then the door is locked from outside but as soon as I take my finger off it pops back up freely.

I tried to restrict the buttons movement a bit with a piece of cable tie wedged down to add friction but this made it go into bouncing mode banging up and down rapidly. So I removed that and it’s back to initial state. Is it a spring issue?

Does anyone know if there are airbags in these door cards to be wary of should I attempt to have a look further. I’m happy to do my own work on it.

Thanks for reading.

 

[mattkh]

A wild shot.
Your car has a vacuum system to hold down the 'button'. Sooo the pipe for the vacuum for the NSR door has come off the junction at the pump end. The vacuum pump may be in the boot.

 

[Stuw2008]

A wild shot is all it may take. Thanks for your reply and idea. It sounds plausible to me. The odd thing is I’ve been to have a look for the pump and so far no joy finding it. It must be under the floor trim or somewhere. However after weeks of it not working it’s now deciding to lock properly. Maybe moisture in there or an intermittent vacuum problem.

Thanks again. Now to find the elusive pump....

 

[Stuw2008]

Nope. It’s packed up again.

 

[mattkh]

Nope. It’s packed up again.

Google 'rowe a classinfo' and take it on from there. Bags of info.

 

[ajlsl600]

On w168 its in boot next to spare. There is if u Google a tutorial on how to replace it, my wife changed ours whilst I was away here. Shud tell u about connections. Look where pipes pass thru doors as well.

 

[Stuw2008]

Thanks both of you. I have had a good look in then boot area of the W169 and I can’t find it in there. I don’t know if I have to remove the side trim panels but it’s not in the wheel well or under the floor carpet. Will have another search online but so far found Rowes useful site. It’s very useful but not helping me find this elusive pump.

 

[ajlsl600]

OK. Sorrio can u not see pipes anywhere on left, right side of boot.

 

[Stuw2008]

Nothing visible on the W169 boot area. No obvious wires or anything. Before I start removing trim I’m hoping to find out exactly where it is but so far the internet hasn’t been able to show me. Even Rowe’s site doesn’t help. Thanks all for your assistance so far.

 

[mattkh]

Look at the fuse layout chart that came with the car (in the battery compartment) and see if there is any reference to a vacuum pump.

 

[Stuw2008]

Still no joy and having re read Bert Rowe’s excellent pages, he can’t find one on the W169 models either!

 

[Stuw2008]

the W169 does not have a vacuum pump for the door locks according to Bert. No wonder i couldnt find one. Also checked fuse charts and no joy. Will have to attempt door card removal and see whats going on. Anyone have an idea where the clips are on door card etc?

 

[Blobcat]

the W169 does not have a vacuum pump for the door locks according to Bert. No wonder i couldnt find one. Also checked fuse charts and no joy. Will have to attempt door card removal and see whats going on. Anyone have an idea where the clips are on door card etc?

Mercedes switched to electric locking as it’s cheaper and less complex. Not as nice or as quiet though

 

[mattkh]

lEd’s...?????

 

[Blobcat]

@mattkh Auto-correct error - now corrected to "less"

 

[Stuw2008]

Ok. Well having found some useful clips online of how to remove the door trim and then to drill out the 7 rivets or so on the door panel....I decided that was too much for me to be getting on with at this time of year outdoors and so I tried something simpler. I have found that the door buttons either:

(1) work as designed
(2) suffer from too much friction and motor up and down rapidly like a machine gun when you use central locking
(3) suffer from too little friction and float up (like mine)

I have seen solutions for (2) online involving squirting wd-40 etc around the button to reduce friction

My solution for my problem (3) was to apply some tape around the button that protrudes to apply more friction. This works now although it's too much friction so I suffer from (2). To avoid this I manually lock my rear door (open door, push down button, close door whilst pulling handle open) and then central lock the car.

Fixed....for free for now....

 

[V6Matty]

We had bouncing locks and after a round with a repair kit only last 6 months we opted for a new lock, it’s been fine for the last 4 years now

 

[alexanderfoti]

+1 replace the lock!

 

[Stuw2008]

Useful website that may help others on all sorts of Merc issues:

Removing the door panel on Mercedes A-Class w169 - Mercedes Classe A (W169)

With a small flat head screwdriver remove the plastic screw cover present in the central armrest, then unscrew the torx now uncovered. Now remove the side door stop (the one that can only be accessed ...

www.scegliauto.com

this one is for door panel removal with some good visual clues. its in German though.

this one is just step by step photos which helps as well.

https://x8r.co.uk/instructions-new/Mercedes-A-B-R-Class-W169-W245-W251-Door-Lock-Actu.pdf

 

[Stuw2008]

Drivers door handle came off in my hand recently. I ended up having to replace the mechanism inside the door (metal casting had sheared off). Used the above video to help. Drilled out the rivets. Replaced mechanism and re riveted panel (first time riveting). Can now tackle this door lock issue knowing how relatively simple it is and save me some money. I’ve ordered a set of springs for about £10 for 4. Took me a bit of time but will be quicker next time I’m sure.