The W124 that doesn't want to lock

[neilz]

No, no, that's not an invitation for thieves- it does lock but on locking my car with the remote fob, the lock tab on the passenger door usually only goes half way down (so I have to unlock car again, open the passenger door from the inside (my car's very precise about this) and push the tab down manually (which locks both doors)) The driver-side door does do this very occasionally instead of the passenger one.

It's a 1995 W124 E220 coupe

Thanks for any help!

 

[300CE]

Might be worth spraying some wd40 in all the locks first Neil to see if this helps (made mine lock a lot more smoothly). Welcome to the forum.

 

[neilz]

Thanks, I've been lurking for over a year and hope to learn from here! I tried lubricating them a couple of weeks ago but it made no difference, it feels like they're catching on something. The key fob makes the driver's one lock perfectly most of the time but not the passenger one.

When I park I have to push the passenger tab down to lock the doors and the strange thing is it goes down smoothly, when I use the key fob instead of pushing one of the tabs the passenger one goes down half way and when I try to push it further it won't budge one bit. If I open then open the passenger door with the handle inside and push the lock down (or maybe after doing that twice) the tab springs up and both doors unlock again and I can lock it by pushing the tab down. Sorry if I'm repeating myself, I'm trying to give every symptom I can think of, because I haven't a clue what could be causing this!

 

[219]

Could be a vacuum leak somewhere .

Oh BTW , use proper graphite lubricant on locks , WD 40 just removes whatever lube might be left and dries the lock out so that it will fail later .

 

[W210 E55]

What alarm is it? If not standard then it maybe the programming for the locking output might not have been changed from the standard 1sec to the required 3sec for Merc's

 

[grober]

Could be a vacuum leak somewhere .

Oh BTW , use proper graphite lubricant on locks , WD 40 just removes whatever lube might be left and dries the lock out so that it will fail later .

Seconded -leaking vacuum actuator/line in the passenger door lock. Points to a small localised leak or none of the other doors/boot/petrol cap would lock either.

 

[neilz]

Does that mean the door card needs removing? I've got to get the window regulator replaced anyway

 

[219]

Yes - it is an ideal chance to do both jobs at the same time .

 

[neilz]

Well, that's more convenient than I expected it to be!

@W210 E55: AFAIK it's the original alarm, it is the Mercedes keyfob.

Oh, talking about keyfobs, you know how much Mercedes "Chelsea" (actually in Wandsworth) charged me to have the central locking fixed on my W202 C200 (yes, the one which died a week later from ECU failure rendering it undriveable)? £750! For a car I paid £2500 for and sold for £350 to someone who probably broke it up for spares (everything was perfect apart from the engine, absolutely no rust, spotless interior )

 

[adile220]

Hi there,

Was a resolution met? I am having identical issues!

All the Best,

adil

 

[millo777]

If you're taking the door card off be super careful with the wood trim around the seat controls ( the first thing you need to remove). They are incredibly easy to chip and eye wateringly expensive to replace....I speak from personal experience.

 

[Paul64]

I have an odd occurence today in my 124 300D - the car has the infra-red locking / immobiliser system that works correctly from both the drivers door and estate hatch however, today, I noticed that the when my elbow knocked the locking button on the top of the door down, the rest of the car didn't lock.
I tried the locking button on the centre console and although with the engine off, it's possible to hear the vacuum motor run for a couple of seconds, the doors still don't react.
Considering the remote locking from the key-fob works, does anyone have any pointers for the weekend when I set to to fix it?

Thanks in advance!!

Paul

 

[neilz]

Hi there,

Was a resolution met? I am having identical issues!

All the Best,

adil

Sorry for such a late reply, never saw your post! I am pretty sure there was a vacuum leak (the locking uses a vacuum system). The car's now been sold (apparently to be restored) and I never got it fixed though.

@Paul - You might have the same issue, if the pump makes a sound and nothing happens there might be a leak. Just an informed guess but I'm quite sure it's that

 

[Paul64]

Hi Neil,

That's the odd thing - when using the alarm fob, the system locks all doors normally - it's only when operating by the switch on the console or locking the door with the button on the door itself that it doesn't work.
When the switch on the console is operated, you can hear the pump run normally but there's no action...

Paul

 

[grober]

Chances are you have some sort of fault with the drivers door lock mechanism/ microswitch which acts as a "master" for the entire system. try looking at the relevant pdfs this section 72 Doors

 

[Paul64]

Thanks Graeme, I'll check it out tomorrow. Good link there to the manual too!

Paul

 

[aircondoc]

I've recently had similar problems with my A124. Would lock only from boot, not door, not from fob at all. My ex bro in law does car electrics and he said it was the pump. When you looked in the casing there was a burnt out bit of the circuit board.
Got a new s/h one on ebay and all correct now. £59.99 against about £250 from stealer.
Check the part no though (on the casing) as the epc catalogue lists them for immobiliser etc.