Help! W124 unlocking itself at random!!!

[mccrackenj]

Hi chaps - hope some central locking experts can help.

The E220T's central locking has started playing up.

1 - it will lock with the remote on the key fob no problem - all 5 doors

2 - it will NOT unlock with the remote; green light in the door flashes as it is supposed to but nothing happens

3 - it will unlock with the key in the passenger door, again all 5 doors unlock OK.

4 - it usually will NOT lock with the key in the door lock, i.e. passenger door locks but the other doors usually do not.

5 - and this is the big problem - after locking it will unlock again anything from a few minutes to several hours later. I have checked it 3 times since 6 pm, 1st 2 times it was locked up OK, but 10 mins ago it was unlocked again??!!

So, I have a car parked on the street that I know is going to unlock itself sometime between now and tomorrow morning.

Any ideas?


Thanks all.

[mccrackenj]

Further minor update:

The car has an alarm, don't know if dealer fitted or aftrmarket and don't know exactly how it operates as I've no instructions whatsoever for it - but messing around with the 2 buttones on the alarm fob, followed by different combinations of flashing indicators etc, seeems to have made a difference (maybe coincidental?)

Now the CL works perfectly from the key fob, i.e. all 5 doors lock and uunlock properly. But it is still unlocking itself, it was unlocked this morning.

I've locked it again but I bet it will be unlocked when I get home.

[idiotgap]

Hi John,
The usual response to any query involving an old merc with the 'original' alarm (often dealer fit) is to remove it. You might get away with de-activating, is there a key and switch?

I've garnered this info from reading threads rather than practical experience with your particular problem, my w124 remote locking woes were due to a bad fob which was resoldered.
Cheers,

[mccrackenj]

Hello Dave

Thanks for your reply.

My first thought on buying the car (even before this problem occurred) was to have the alarm system ripped out. My previous experience with old aftermarket alarms is that they're more bother than they're worth.

So maybe I'll do that and see if it helps.

I locked it again last night by opening the back door and pushing all the locking buttons down. The drivers one went down OK, but then the CL pump pushed it back up again and reopened the other doors. I pushed it down again and everything locked and, when I left the house this morning, it was all still locked.

That's a bit of a faff, but I could live with it for a few weeks until I had time to take the car to an autospark to get the alarm system taken out.

[mccrackenj]

Just to add further detail, there is no apparent pattern to the spontaneous unlocking.

Can be anything between 2 hours after locking to over 12 hours. WTF?

[mccrackenj]

A further update - yesterday it stayed locked for over 24 hours, then unlocked itself again overnight!

But now the key fob is locking the car but not unloving it. I have to unlock with the key. No rhyme or reason to it at all.

Anyone got any clues?

Is it worth my while just buying a 2nd hand pump on Ebay (even though the pump seems to be fine) and replacing it anyway to see if it makes any difference?

[harry kular]

just posted in your other thread, I've got a vac you can use if you want. It was the original from my s124, but my mate changed it over, don't remember why though, to my knowledge it worked fine.