Central Locking issue

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smugmushroom

New Member
Joined
Mar 20, 2014
Messages
5
Car
E300 TD W210
Just bought a cheap, mint condition W210 E300 TD Elegance 1999.

However, the central locking doesn't work.

It has a a new chrome style key, that works in the ignition without issue. The unlock button activates the indicators and turns on the interior light, but doesn't work the locking system. The lock button does nothing, as does the boot unlock.

Inside, the dash lock button doesn't work, and neither does the rear head rest recliner button.

I have tried the sync process without success, pos.2 in ignition, hold lock, remove key and press unlock 5 times, release lock.

Please help me identify this issue and fix it!!

Thanks
 
Your vacuum pump seems to be faulty or is not connected or has a bad connection or has a blown fuse.

The vacuum pump locks and unlocks the door and unlocks the boot via the boot button on the remote and/or the boot open switch on the centre consul.

Dec

[YOUTUBE]UskH0ZZ6GlI[/YOUTUBE]
 
Thanks for the replies.

I've gone through all the fuses today and they are all ok.

Not sure if this is connected in any way, but the dome light stays on like there is a door open, even when driving. I've checked all 4 door pushpins, none are stuck in. I couldn't see the pin for the boot, if there even is one?

The pump under the rear seat doesn't seem to do anything, so I will order a replacement and see how it goes.

Thanks again, if you have anymore input, even if you think it's trivial, please post.
 
As the car is new to you, are you setting the dome light correctly?
Page 159… http://www.mbusa.com/vcm/MB/DigitalAssets/pdfmb/ownersmanual/2000_e320_e430_e55amg.pdf

You could test the alarm system.
Leave a window open.
Lock car with remote… hazards should flash 3 times
Wait 1 minute
Reach inside open window and open door/s bonnet
Alarm siren should sound and hazard lights should flash
To disarm alarm, unlocking car or put key into ignition.

Dec
 
Last edited:
The interior light staying on is probably a symptom of the fault disabling the PSE pump. Both work in conjunction using the CAN for communication.
 
Dieselman, would you be so kind to elaborate on that statement?

For instance, what is the CAN and how does it relate to my problems?

Thanks again for your time.
 
Just fitted a replacement PSE pump from a E320CDi, for some strange reason it doesn't have the air outlet for the boot catch, but no biggy, the central locking now works. The light pod is still not right though, staying on after doors have closed.

Please could anyone suggest where to look next?

Thanks
 
As the car is new to you, are you setting the dome light correctly?
Page 159… http://www.mbusa.com/vcm/MB/DigitalAssets/pdfmb/ownersmanual/2000_e320_e430_e55amg.pdf

You could test the alarm system.
Leave a window open.
Lock car with remote… hazards should flash 3 times
Wait 1 minute
Reach inside open window and open door/s bonnet
Alarm siren should sound and hazard lights should flash
To disarm alarm, unlocking car or put key into ignition.

Dec

Did you test the alarm?
A faulty alarm could be causing the light issue.

Dec
 
before I replaced the PSE pump, I couldn't test the alarm, as I couldn't lock the doors with the fob. Now though, I can lock the doors with the fob, but the hazards don't flash and I'm guessing the alarm doesn't arm. Hazards flash on unlock though.
Tried your instructions, but nothing, no alarm.
Where do I look for this alarm? ive checked all the fuses, they are fine.

Thanks
 
Ensure the car is unlocked with the remote fob when you unplug the siren.
Leave it unplugged as its definitely faulty because it failed the test.
Replacement is around £100 if you DIY.
See video below.

Dec

[YOUTUBE]zChaQHHaeJU[/YOUTUBE]
 
I recently had a problem with our E320 Estate, W210 (or is it S210???) whereby the rear window wiper would not operate. I eventually took it to a Mercedes Specialist AH Lock in Rushden Northants, who diagnosed the problem as a faulty vacuum pump, apparently the signal to fire the wiper routes through it. I replaced the vacuum pump and I had the same issues with the lights staying on and the central locking not working at all. I popped back to AH Lock and they discovered that I hadn't fitted one of the plugs correctly, it was slightly out of kilter, and when they refitted it correctly everything was working properly, including the rear wiper :) I am mentioning this because your symptoms sound so familiar that you may want to just check the fitting of both of those little plugs. The reason that the rear wiper didn't work was because some previous owner had fitted a SALOON vacuum pump to our ESTATE and there is no output for the wiper, everything else worked but not the wiper. If you want a good vacuum unit for a SALOON give me a PM and we can sort something out :)
Hope this helps

Keith
 

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