C200 W202 - won't start & central locking broken

[AndyRobin]

Hi all,

Apologies for the long first post but I have been having a nightmare with my 1998 C200 W202 Elegance.

I went on holiday for 3 weeks and when I came back it would not start.

The remote key would not open so I used the manual one to get in via the drivers door. I cannot get the manual key to open the boot though as the key will not turn so I could not get get to battery. After reading on forums I learnt about the jump point under the bonnet so managed to get it open using power from a donor car. I then jump started the car via the battery in the boot. I drove the car for 30 mins, came home, turned it off but it would no start again on its. So I thought it must be a duff battery.

I bought a new battery today to install and and tried to get the boot open using the same method as before but this time it would not open! Gutted!

So I folded the back seats down and climbed into the boot and was able to replace the battery after great struggle.
I left the other car connected up via the jump point under the bonnet during the battery replacement in order to keep power to the car to avoid stuff getting reset.

So, the new battery is in but...

1. Most annoyingly the car still does not start! When I try, all the lights on the dash light up but nothing happens.
2. The remote key fob will not open the doors. The side lights flash on the car so it seems to be receiving a signal.
3. The button to lock/unlock on the dash does not work.
4. The boot still does not open either with the button on the remote key fob or using the button near the cup holder.

There does seem to be power from the new battery as the radio, windows and lights all work fine now but didn't before.

I really don't know what to do now? The car started up fine when I jumped it but now with a brand new battery it doesn't?

The central locking system seems dead now too, even though it was fine the other day.

I don't know if the 2 problems are linked so didn't know which issue to tackle first?

Any help would be greatly appreciated!

Thanks,
Andy

 

[Dec]

Remove the fuse for the alarm siren, fuse located in boot fuse box.
Unplug the alarm siren, there is a 3 pin plug on the back of it.
Alarm siren located behind front wheel arch liner passenger side.

Unplug the electrical plugs on the vacuum pump then reconnect them after 30 seconds.

[YOUTUBE HD]LTVN2nnp9Kk[/YOUTUBE HD]

Check all fuses in fuse box driver side and fuses in ECU box (big plastic lid, 4 screws) on opposite side of engine bay.
Try to unseized the boot lock with repeated applications of WD40

Test your remote through a digital camera, you won’t see the Red light as your key fob is different to the one in video but you should see a Purple light flash as you hold down any of the buttons.
If you have a spare key then try it also.

[YOUTUBE HD]zQhwvjw29NA[/YOUTUBE HD]

Dec


Edit, the button for the central locking and the button to open the boot wont work if the ignition is not turned on to position 2.

 

[AndyRobin]

Thanks a lot for your reply Dec! I was really hoping you would see my post as I know you are the expert on this after reading all your other posts.

I will try what you suggest tonight when I get home.

Sorry if this is a stupid question, but do I need to take the wheel off to disconnect the alarm siren like in the photo?

Should I attempt to get the boot open by removing the bolts holding the catch for the lock (photo attached)? I read this in another post where you helped someone open their boot by doing this through the first aid hatch.

I'll keep trying with the WD40 on the lock but I am a bit worried about breaking the metal key blade as I have already bent it a bit trying to open the boot. It still works in the drivers door but only just, it is getting quite stiff to turn.

Sorry, just one other question about the manual key. I read that the valet key will only open the doors and not boot? Could this be the problem? I only have 1 fob as the other was lost by previous owner so not sure if I have the master or valet.

 

[tonyc280]

Dec I'm surprised you don't have vented disks at the front. My old c200 w202 had them at the front, Cheers, tony.

 

[Dec]

It will be really awkward to get at the siren without taking the wheel off but you can try, you will need to turn the wheel full lock to make space, I know you cant get at your jack as its in the boot but jacking the car up… without taking the wheel off… will open up a lot more space to work at removing the wheel arch liner.

The wheel arch liner doesn’t come off when the 3 nuts are removed, it just folds back, it will be very awkward as the wheel is still on and in the way.
However, no need to remove the alarm fuse in boot fuse box if you are going to unplug the alarm siren.
The car battery can be recharged at the point in the engine bay that you used before.


There is only one metal key blade, it works glove box, drivers door and boot… that is, when the lock barell is not seized.
Older cars like the W124 did have a separate master keys that would lock the boot seperatley but you have one key blade only which works all locks.
Your car, when new, would have come with a flat emergency ignition key that will start the car, it has no buttons and is the same as the one in picture, bottom left. You may or may not have this flat emergency key with your car documents wallet, have a look see.

Picture source… Do I REALLY need to buy a new smart key? - MBWorld.org Forums

What type of remote fob do you have, top left or top right in picture above?

Don’t force the key as it may snap, use hand turning force only.
Try working the key into the slot after each squirt of WD40.
Flooding the lock with WD40 while the boot lid is open is much better than when the boot lid is shut so it would be beneficial to remove the two bolts to get the boot lid open.

How far in will the key blade enter the lock barrel?


Dec

 

[Dec]

Dec I'm surprised you don't have vented disks at the front. My old c200 w202 had them at the front, Cheers, tony.

My previous 1995 W202 didn’t have them either, maybe yours are added on by a previous owner, I don’t need good brakes anyway… I don’t get to go all that fast where I live.

Dec

 

[tonyc280]

Dec I don't get to go that fast either but glad my C280 is fitted with vented disks just in case i do get to overheat them for some reason, Cheers, Tony.

 

[AndyRobin]

Thanks again Dec, really appreciate your help!

Sorry again if this is a dumb question but is it essential that I unplug the alarm siren? Could I get away with just removing the alarm fuse or neither? I am not sure what this step does. Will there be a problem unplugging the electrics on the vacuum pump if I don't first disable to the alarm siren?

Thanks for the info about the keys, I must have read a thread for the W124. I have read so many posts now I am getting confused.

In the photo I have the fob in the top left corner.

I have viewed the fob through a camera and I can see a purple light when pressing each of 3 buttons so it seems to be working ok.

Regarding the key blade - originally it only went half way in but after applying a lot of force it will go all the way in. I just hope I didn't break anything forcing it in. It just won't turn at all.

I think I might get a copy of they key cut tomorrow as I am really worried about snapping it. It is already bent after trying to turn it with some pliers. I will get one with a head if possible to make it easier to turn.

 

[Dec]

Unplugging the siren is a precaution, the siren contains the ECU of the alarm system, the are known to be faulty when the pass 10 years of age and can cause all sorts of problems, you don’t have to no but do test it when you get sorted out and back to normal.

If you get the boot open then take out the alarm fuse just in case it is causing a problem, I think removing the alarm fuse will disable the alarm but removing the fuse doesn’t stop the siren from drawing current from the battery.

Test alarm… http://www.mbclub.co.uk/forums/electronics/169666-w202-how-test-car-alarm.html

The problem is that those keys usually snap with force resulting in a piece of key being left inside the lock barrel. Best to remove the lock from inside as you have easy access to the inside of boot from cabin.

When you get in via the 2 bolts inside boot this is the result below

Then remove the lock and push lever #3, below, upwards, this will release the trapped boot latch from the boot lock jaws.
Remove lock… W202 Boot Lock Fix. - Mercedes-Benz Owners' Forums

It would be best to leave the latch off until you get the boot opening problem sorted… keep at it with the WD40.

You could attach a weight to the inside of the boot to keep it shut, for now, no one would know that the boot lid is not locked.

Dec

 

[AndyRobin]

Hi again. I feel like such an idiot right now, but I just tried to start the car and it worked it!! I am guessing on this but I think yesterday I may have opened the car using the key blade and tried to start the car without pressing the unlock button on the fob first in order to disable the anti theft alarm? Is that right? Sorry about that I should have figured that out yesterday before posting.


The central locking is still not working though so I am going to try and get to the vacuum pump like you suggest.

Thanks a lot for the information regarding the boot lock. I'll try to do this because everything will be so much easier with the boot open rather than clambering around in the boot from that back seats.


I really appreciate your help with this, thank you Dec!

 

[Dec]

No problem Andy.
No what you said above wouldn’t have had any effect on the non starting, if you were, with the metal key blade, to unlock and open the door of that car while the alarm is armed then the alarm would go off, that’s normal, if you then were to turn the remote key in the ignition then the alarm would be disarmed.

The jump starting must have upset something and that’s why it didn’t start.

Is the central locking working from the inside cabin switches… ignition must be on.
As the central locking was working before this trouble then its very likely its something simple that’s at fault
Check fuses as well.

By the way, if the metal key blade can lock/unlocks the glove box then its fit enough to unlock the boot lock… if it weren’t stuck.

Dec

 

[AndyRobin]

Hi Dec,

Thanks for the info. I am really not sure why it starts now then, probably as you say it was something to do with jumping it.

The central locking does not work from the inside switch on the dash. The boot release switch does not work either.

I remember that the last time I locked the car when the central locking was working, I could hear a noise from the boot like the sound of a small motor. It made a noise for a good 30 seconds or so. Could this sound be the vacuum pump motor failing?

Thanks again for all your help.
Andy

 

[Dec]

A good vacuum pump will run for about 2 seconds when you lock or unlock the car, if it ran for 30 seconds then there is a problem, either the vacuum pump motor has died OR its fuse has blown OR there is another fault, perhaps on the vacuum pump circuit board.

If you press the lock or unlock button on the remote fob, do the hazards warning lights flash at all?
Is the petrol flap open or locked?

Dec

 

[AndyRobin]

Thanks Dec.

Yep the hazard lights do flash when I press the lock or unlock with the remote fob.

I am not sure about the fuel cap, will check that when I get home from work and let you know.

Many thanks,
Andy

 

[Dec]

I had forgot that you can get inside the boot from the cabin, if you can get your hands on the vacuum pump then there is another way of opening the boot lock without the aid of the pump or metal key blade.

The W210 vacuum pump in the video below has the same layout as your W202 vacuum pump.

[YOUTUBE HD]UskH0ZZ6GlI[/YOUTUBE HD]

Ebay W202 vacuum pump… MERCEDES C CLASS / W202 CENTRAL LOCKING VACUUM PUMP 2088000548 C180 C200 C220 | eBay

Normally, when you unlock the boot with the remote fob, the pump blows air through the Yellow air line that goes to the boot lock… see 1 minute into the video… and the boot lock is “blown” open.

If you remove this boot lock airline from the pump and blow as hard as you can through the end of the tube then the boot lock should open.

If blowing from your mouth doesn’t work then the assistance of a garage/service station airline might help.

Dec

 

[AndyRobin]

Hi Dec,

So bit of an update on where I have got to. I checked the fuses associated with the Central Locking System but none looked blown.

I managed to get to the vacuum pump. I disconnected the electronics for 30 seconds and connected it up again, but still no luck.

I disconnected the airline I think controls the boot and tried blowing but wasn't able to open it.

By the way, I noticed a slight difference with my pump and the one in the video. The connection at the top right which goes to the boot has 3 white airlines in mine but in the video there is 1 yellow airline. Not sure if this matters?

I have also been regularly applying WD40 to the boot lock but still cannot get the metal key to open it. I'll keep trying with this. I might try and take it off at the weekend and try to follow your guide on cleaning it up.

Is it worth taking apart the vacuum pump or should I just bite the bullet and order one off eBay? Is there anyway to confirm it is the pump?

I noticed on the eBay auction you posted a link to it says that 'it will require coding to your remote in order to work'. Is this correct? Is the vacuum pump actually coded to a specific remote fob? Any ideas how to perform this coding?

Thanks for your help.

Andy

 

[Dec]

I don’t know about the coding, I have heard of people just fitting without coding and the seem to work ok.
Coding involves putting the car on STAR diagnostic so you need to go to an MB specialists to have it done, that is if it is needed.

It’s VERY IMPORTANT that the ebay pump part number is the same as your existing pump part number.

I would definitely hold off buying another pump until you examine the existing unit properly.

The layout in the ebay picture below does agree with you alright, no mention of codeing on this one… MERCEDES W202 C230 KOMPRESSOR SPORT CENTRAL LOCKING VACUUM PUMP | eBay

If yours is the same lay out as the above picture then the boot air tube must be a single which must be either one of the two on the top left…. unless there is 2 other tubes in the two vacant holes bottom right of picture.

So many differing variations… https://www.google.ie/search?q=w202...gBA&ved=0CAgQ_AUoAQ&biw=1749&bih=871#imgdii=_


When the boot is unlocked via fob or boot opening pull up switch in cabin, the vacuum pump blows air into the boot lock;
#1 Actuator pushes #2 down and #3 is raised up which unlocks the boot lock and the lid pops open.
Mouth blowing should do it, but if mouth blowing doesn’t do it then a garage airline should.
Its a question of getting the right tube to blow air into.

Dec

 

[AndyRobin]

I have just had another look at the pump. I took out all the airlines. Please see attached photo - that is an identical setup to mine. The ones I have labelled worked fine when I blew. The fuel cap opened and closed really easily. The doors opened quite easily too. I couldn't close them though.

The single yellow airline in the top left and the 3 white airlines where impossible to blow, there seemed to be a lot of resistance.

I just wanted to check whether I have checked all the fuses. I checked in the boot and 1 location under the bonnet on the drivers side. Is there a 2nd location for fuses under the bonnet? Please see attached photos of where I checked.

My pump part # is 2108001048 like in the link the one on eBay from the C230 Kompressor.

Cheers,
Andy

 

[AndyRobin]

Forgot to mention, when I push the central locking button on the dash I can hear a click from the pump in the boot. Not sure if that is relevant?

 

[Dec]

8 &17 which are Green 30amp fuses to do with central locking.
Do you get the click from the pump when you use the remote fob lock button or unlock button or boot button?
Do you get the click from the pump when you use the pull up boot switch beside the mirror adjuster switch?

It could be that the pump motor is broken, perhaps it can spin when power is supplied but it can’t blow air.

It might tale the force of a garage air line to make it work, its either the 3 white or the top left yellow that you haven’t marked.
There is always the possibility thst there is a leak in the boot airline, a leak in an airline could would explain why the pump motor ran for 30 seconds as you mentioned in a previous post.

Dec