w202 central locking problem

[butler23]

Hey guys,
Anyone clued up on the central locking system? The remote has never worked but the button on the key card has so ive always used that... but it was always abit tempremental, so now and again i would have to turn the key in the ignition and press the button a few times and it would work again for a few days/weeks.
Eventually, this stopped working altogether and the button on the dash to lock/unlock the doors wont work either... however, you can very faintly hear the vaccum/motor when you press the button but obviously doesnt do anything.
So, any ideas?? ☺

Thanks.

 

[Dec]

What year is the car?

When you successfully lock the car with the remote, the vacuum pump should run for 2 seconds and the door pins should drop instantly, same, in reverse, when you unlock.

The internal switch should also cause the pump to run for 2 seconds when you lock or unlock.

Dec

 

[butler23]

Its a 96 buddy. Hmmm, see nothing happens now, remote wont work and the button on the dash wont work either. U can just very faintly hear the vacuum but nothing happens. Now a few days ago i did notice a green vacuum pipe off under the bonnet above the airbox, but im not entirely sure which hole its meant to go in. Could this be related do you think or any other explanation? Cheers

 

[Dec]

Try disconnecting all the electrical connections to the vacuum pump, check that each connection is tight and clean with no sign of corrosion.

You can also open the pump casing as illustrated below to inspect the PCB for damage/broken joints or corrosion.

I don’t think that would affect the door locking, got a picture of the Green vacuum pipe area?

Dec

 

[Dec]

The below is off a 1994 W202, I have no idea what each tube does, others may know more.

Dec

 

[butler23]

Ok mate thanks, i will inspect the pump next. That last picture u sent, its the green pipe that is disconnected but i have just spoke to my brother who owned the car before me and he disconnected it while the central locking was still playing up so it cant be that, although it would be nice to know what its for lol

 

[Dec]

The fault would seem to be with the vacuum pump but you should also investigate the flip out remote fob, its PCB, it may be repairable.
Be very careful when you open the remote case, your remote may contain an immobiliser chip which is glued inside the remote case below the Red lens, if this SMALL chip drops out, as you open the remote, and it is lost, then the car can’t be started.

Dec

https://www.youtube.com/watch?v=lCqfivH9-Dg

[YOUTUBE]lCqfivH9-Dg[/YOUTUBE]

 

[butler23]

Ive already changed the key fob as the flip didnt work with the 1 that came with it. So its not related to that as it had the same problem with the old 1.

 

[butler23]

But im thinking it must be the pump or the lines.