R170 alarm and locking

[Smokey Fontaine]

Yep, still working on it.
Does anyone know how to switch off the alarm long enough to get the locking unit out of the boot to work on it?
Mine has failed locked so every time I open a door or unplug the unit in the boot the alarm goes off. If it stays unplugged the alarm keeps repeating.....

I have a broken pin on one of the connector blocks. I have the knowledge to replace the pin I just need to alarm to shut the f**k up!

Regards,


Smokey.

 

[Dec]

The alarm siren has its own rechargeable batteries which are what is powering the siren when it is unplugged.

Normally unlocking the car with the remote will disable the alarm, however, your remote must not be working so as to disarm the alarm on unlocking, and maybe it needs new remote fob batteries.

The siren should sound for 30 seconds and the hazards should flash for 3 minutes when triggered.
Your best bet is to unbolt the alarm when it is quiet, then unplug it, it should go off when you unplug it as it’s still armed, you can now bring the siren to a place where you can store it until it depletes its internal batteries… inside the fridge springs to mind.

Dec

 

[Smokey Fontaine]

Thanks Dec, both my fobs are ready on 3v per battery so I would like to think they are OK. Once sat inside (with alarm sounding loudly) the button for central locking (which I believe is the key in a Window/door button) also does not operate the central locking. I can hear it trying in the drivers door though....
I believe the module in the boot controls the alarm too or am I wrong?

I have found a pin snapped off one of the connectors into the locking unit in the boot so I am guessing that is part of the issue, also there was much blue, coppery sh*te around the connectors. Cleaned that off, just need to swap the pin and refit.

Or am I barking up the wrong tree??

So, gimme a clue. Where is the alarm module under the bonnet? I like the fridge idea though. Hehe.

 

[Dec]

As the central locking vacuum pump is damage with corrosion and a broken pin, it is upsetting the alarm, Disconnect the siren for now till you rectify the vacuum pump faults.

I think the alarm siren is located under/around wipers mechanism, you might need to set it off to find out.
See also, opening vacuum pump… https://www.google.ie/search?q=w202...=ZQzGV9SWM6PWgAacz7WoDg#imgrc=HWRgh_cpH-SULM:

If the car is unlocked with the remote then the alarm will be disarmed so it can just be unplugged and it shouldn’t go off again.

If, because of the vacuum pump fault, you cant unlock the car with the remote then the alarm will remain armed so as soon as you unplug it it will sound off, so I would unbolt the siren first then unplug it… and put it in the fridge if it wont shut up.

Make sure you can open the boot lock with the emergency metal key blade as the lock can become seized up due to irregular use with a key.

Dec

 

[Smokey Fontaine]

Thanks Dec, all good info.

I have no problem setting the alarm off it happens very time I open the door. The remote won't do jack so I guess, open the door, open the bonnet locate and destroy the alarm (unbolt and muffle ASAP).
Fix the c/l unit (possibly) refit and cruise.....

I am already in the boot and locking unit split apart, as soon as you remove the connectors the alarm goes off (correct operation...I suppose).
I just need to replace the corroded pin and build it back up, hopefully that's all the damage there is. it's the siren sounding which is the ball ache, I am sure the neighbours are sick of it already. I know I am.

Thanks again for the help, you certainly put me on the right track.

I will report back when I have tinkered.

Thanks for the help Dec,much appreciated.

Regards,

Smokey

 

[Dec]

These alarms all give trouble when the are around 10 years old, so, if it’s the original alarm siren then it may be faulty too, as well as the vacuum pump fault/s. The alarm siren contains the brains of the alarm system. See… https://www.google.ie/search?q=Merc...ved=0ahUKEwjMy7fdu-vOAhVCLSYKHaytCFQQ_AUIBigB

Because the vacuum pump is faulty, it’s not allowing the alarm to disarm when you unlock with the remote fob.
Tampering with the alarm, and I suppose the vacuum pump while the alarm is armed will cause it to go off, that’s what it is suppose to do anyway.

Dec

 

[Smokey Fontaine]

Hi Dec,

I'm now getting towards disparity. I removed the siren (nicely when it is not connected to the car it just chirrips like a demented cricket so it is not too loud, I guess the batteries are tired.....).
I stripped the vac unit and the board was covered in corrosion near the connectors.
I have cleaned it all off and lacquered the pub. I desoldered the snapped pin and replaced it with an unused one from the same connector. Even removed the ferrels from the connectors and cleaned them as much as possible.
Built it all back up and it is still the same, apart from the locking switch on the console now at least tries to do something as there is a little whisper of noise from the back end when it is pushed (only on the open side though not the locked).
I am at a loss and getting towards having to get a garage involved, I really thought I had got it licked but...

The only question mark I still have it the syncing of the remotes. The instructions seem a little vague as regards he long to press the button etc. When I turn the key I get "start error" I don't know for sure if that is because the alarm has triggered or it is because they are not now synced....

I am about to give in, on another note I fitted a nice silver grille today too and it looks really nice....shame it can't move off the drive!

Thanks Dec, any more ideas would be appreciated.


Regards,

Smokey.

 

[Dec]

What year is the car and what type of remote do you have?
If it’s the bladeless type then just putting it into the ignition will resynchronise it, the single button flip out type requires 2 presses of button and insertion into ignition within 30 seconds.

I don’t think the key is the problem, maybe the vacuum pump PCB is now ok and its the vacuum pump motor that is not working, perhaps because the impellor, that compresses the air, has shattered, example…

See… PSE Central locking pump overhall - Mercedes-Benz Forum

Example… mercedes centeral locking vacuum pump repair kit | eBay

https://www.youtube.com/watch?v=9MkpUtLwPN0

[YOUTUBE]9MkpUtLwPN0[/YOUTUBE]

A replacement from ebay might be the only solution, that is if its the pump thats at fault… R170 vacuum pump in Vehicle Parts and Accessories | eBay

Dec

 

[Smokey Fontaine]

Hi Dec,

yes, I have the flip out, 2 button blade type the car is a 2001 on an X plate.
would applying 12 volts to the pump show if it operating correctly and spinning?

Regards,

Richard

 

[Dec]

Yes and if you disconnect the tube you should be able to feel the air being sucked or blown.

Is the below the same as your instructions to synchronising the remote key fob?

Dec

 

[Smokey Fontaine]

Hi Dec,

That is what I read on line and on this forum, but I didn't see any pics so wasn't aware the differences in fobs.
If you say inserting into the ignition does the sync for my 2 button type then good enough.
I will turn my attention to the pump and have a look at that on Sunday when I am home.

Thanks again, update you soon.

Regards,

Smokey.

Yes and if you disconnect the tube you should be able to feel the air being sucked or blown.

Is the below the same as your instructions to synchronising the remote key fob?

Dec

 

[Dec]

Because of the vacuum pump being faulty, it’s probably not possible to sync the remote properly, in any case the vacuum pump does seem to be the main suspect.
2000 SLK User Manual (American) See page 225… https://www.mbusa.com/mercedes/service_and_parts/owners_manuals#!year=2000&class=SLK-Class

Picture... Imgur: The most awesome images on the Internet

Dec

 

[Smokey Fontaine]

But, even if it is the pump at fault. Why can I not turn off the alarm with the fobs? Surely even if the doors won't open I would expect the lights to flash, get the beep and the alarm and immobiliser to disarm??? Or am I being thick?

Regards,

Smokey.

 

[Dec]

I don’t know exactly how it all works, my understanding is when you lock the car, the pump locks the doors and arms the alarm. When you unlock the car the pump unlocks the doors and disarms the alarm.
Either the remote fob isn’t working or the unlock button on the remote fob is faulty or the pump is faulty, remember you say the central locking switch inside the car doesn’t work so therefore the pump is likely to be the problem.
.

Dec

 

[Smokey Fontaine]

Hi Dec,

Damn it!!! Still no joy.... :fail

I have opened the unit again, and took the pump out. It both sucks and blows when on external 12v.
I can now see how the pump would tell the alarm to activate and deactivate as there is a sort of encoder which is mounted on the board and wired to the pump. I assume that is the interface, once the pump operates the encoder operates the alarm (all assumption by the way).
Anyway, that's not an issue. The fact is the pump seems to do its job and suck n blow. But no central locking. I have no reason to think the fobs are not working as they both light up when viewed through a camera and both have new batteries. I will replace the batteries again tomorrow just to be sure.

Since I cleaned and lacquered the pcb, the button on the dash does attempt to operate when you push the bottom, when pushing the top there is no noise or movement.

I am getting to the end of things to try....

Anyone know of an independent Merc garage near Chesterfield, Derbyshire?

Regards,


Smokey.

 

[Smokey Fontaine]

A development though. The c/l does lock with the button on the dash now. So it seems it is just not operating via the remote(s).
I would be amazed that both fobs have failed since all that has happened is that we went on holiday for 2 weeks and the car hasn't moved. I will replace both set of batteries again tomorrow, hopefully it may show something up....


Regards,

Smokey.

 

[Dec]

The fact the button on the dash seems to work a bit, it does seem to point to the pumps connectors or PCB, something that’s been damaged by the corrosion and that you can’t detect by eye.

Dec

 

[Smokey Fontaine]

If it comes down to that unit and I get a used replacement, does it have to be coded or synced to the siren or car or whatever?
I do get a constant "Start Error" when I turn the key.

Regards,


Smokey.

 

[Dec]

If you get the correct pump for your car it should work when fitted, a lot of people have done that to solve vacuum pump problems… however, it’s a gamble as you don’t know for sure that the pump is at fault. If you got one for 50 quid it might be worth a bet but those on ebay seem to be around £300.

If you google - mercedes r170 start error – you get this… https://www.google.ie/search?q=merc...GEQ_AUICSgC&dpr=1#q=mercedes+r170+start+error

Getting it checked out by an good independent Mercedes specialist with Star Diagnostics might be the wisest way forward.

Dec

 

[Smokey Fontaine]

Hi Dec,

Just to let you know I have managed to get the SLK into a local garage for diagnostics.
I don't know if they will have any joy but I have left it with them until they can spend some time playing with it.......

Thanks for all your help, I will you know how I get on.

Thanks again,


Smokey.