E class 2004 (w211) interior lights on and battery drained

[Rupz911]

Hi guys I need your help.

I just bought a E class 2004 CDI (W211) a couple of weeks ago and it was running fine, but recently it has been acting up.

I take my car to work and park it in a public street. I leave in the morning and return around 5-6pm and find the interior lights on and the car telling me my "convenience" features are disabled. After taking it for a long run it was OK. But then i had an issue with the door mirrors not folding in like they should.

On Sunday the car was completely drained, in that the door opened via central locking but the car wouldn't even turn over. So i jump started it and took it for a 30 min drive. I stopped once to collect some things and when i came back in to it the car alarm was going off every 30 seconds, even while i was driving. it stopped after 5 mins.

I only do short journeys to and from work and its no more than a 10 minutes drive each way, which may account for the low battery but my previous car i did the same with no problem. Any ideas what the issue may be? Ive read up on here lots of things with it being the SMB battery and it needing a full reset but nothing thats been solved. I was hoping to get it solved and change the title to reflect. Will also provide an update too.

Thanks in advance and sorry for the lengthy OP. im not usually this wordy

 

[Dec]

Any idea how old the battery is, if it is the original then its may need to be replaced.
While the car is locked via the remote then the alarm is armed and if the battery in the boot is losing charge then the car alarm can go off.

Dec

 

[Rupz911]

Any idea how old the battery is, if it is the original then its may need to be replaced.
While the car is locked via the remote then the alarm is armed and if the battery in the boot is losing charge then the car alarm can go off.

Dec

Hi Dec, thanks for the reply. The battery in the boot is new(ish) its a replacement (Exide Excel with charge control but cant make out how the heck it works)

So far the car alarm battery hasnt gone off. Only thing i have experienced is the interior light (courtesy light on the rear view mirror) was on and the battery drained.

 

[BlackC55]

You need it plugged in firstly.

 

[Rupz911]

You need it plugged in firstly.

Need what plugged in and to where?

 

[evdok]

Star diagnostic system

 

[Rupz911]

Ahh, the STAR system. Heard a lot about it. Will have to visit MB to diagnose it.

Thanks for your help guys. Will keep you posted on updates.

 

[Dec]

When the window on the battery is Green then the battery is fully charged. If you do a lot of short trips then you need to put the battery on a trickle charger. That battery would need to be charged over several hours, jump starting and going for a spin won’t do it.

When the alarm is triggered the interior light, I think, also comes on, the alarm siren houses the brains of the alarm and is known to become faulty after about 10 years, corrosion on the siren PCB can cause all sorts of faults related to locking and unlocking like your courtesy light and could be draining the battery more than it should.

See… Alarm / Siren Issues : Goes off for no reason/Kills Battery FIX DIY.. - MBWorld.org Forums

Test the alarm by leaving a window open and lock the car with the remote, wait one minute then reach into the car and open the door and possibly the bonnet also, the alarm siren should sound and the hazards should flash.

When you lock thee car the hazards should flash 3 times.
When you unlock thee car the hazards should flash 1 time.

Dec

 

[Rupz911]

Thanks for your help guys. I've left my car at home and the battery charged all day (14hours). I just revisited my battery and there is no green on the battery, only black which points to it needing charging. It may be part fault of the battery needing charging. However, on Sunday night I did a charge over mind in my garage which was approximately 12 hours and it lasts Monday and dies Tuesday night.

Regarding the siren it does work as I was driving home in the car while it was going off. Nevertheless I shall check the siren PCB for any corrosion. If someone an point out where it is

Again, thank you all for your help

 

[Dec]

When you unlock the car you also disable the alarm siren, that is, you disarmed the alarm, it is still getting a power supply, it shouldn’t go off like that when you are driving, this confirms that your siren is defective and needs to be replaced, costs about £90? From MB dealer, in the meantime you can just unplug it and replace it at some time in the future.

Only unplug the alarm siren while the car is unlocked and put some tape over the siren plug to keep it dry if you don’t intend to replace the siren immediately. The siren has batteries inside it so it might go off even while it is removed from the car.

No working alarm fitted means no insurance cover for theft.

Its location is on drivers side (RHD) behind wheel arch liner and is similar to a W210 in the video link below.
How to: Remove a 2001 E320 Mercedes Benz (W210) security alarm siren - YouTube

Was the new battery fitted to the car after it came into your possession or before you bought it?
Just thinking that the car might have been sitting at the sellers premises for months with an uncharged battery.

Dec

 

[Rupz911]

@ Dec

The siren going off was a one time incident (best of my knowledge). Although saying that i will have a look and see if the PCB is knackered. My dad is an electrician so he can check to see if the power is being taken from any of the components inc the siren.

One thing i will mention is the car i bought was off someone who had it sitting in their rive for the best part of 6 months. So the battery was was fitted by them.

I charged my battery yesterday (around 7..30am) and left it to charge for a full 24 hours. I had a look at the indicator and it was still back, indicating that the battery still needs to be charged. What i have decided to do is to check if the battery if the battery can hold the charge for a full day without putting in back in the car. Another thought was that maybe the battery needs to be topped up with some fluid but it seems pretty full and there is no typical screws to unscrew and fill up.

 

[Dec]

Did you test the alarm by triggering it as suggested in post #8 above?

If the alarm siren is going off while the car is unlocked and or while it is being driven then it is faulty, for it to sound off only one time is enough to show that it is faulty and a faulty siren would explain the courtesy light coming on and possibly the battery drain, however the health of the battery is still unknown, unplugging the siren may give some indication, over time, just how healthy the battery is.

Dec

 

[Rupz911]

Did you test the alarm by triggering it as suggested in post #8 above?

If the alarm siren is going off while the car is unlocked and or while it is being driven then it is faulty, for it to sound off only one time is enough to show that it is faulty and a faulty siren would explain the courtesy light coming on and possibly the battery drain, however the health of the battery is still unknown, unplugging the siren may give some indication, over time, just how healthy the battery is.

Dec

Hi Dec,

no i havent had a chance to test the alarm as the battery has been in my garage charging. I will check how much the battery has drained since the morning and will put it back in the car. Someone will be at home tomorrow so i they can tell me if the alarm goes off. But I will follow your advice as soon as i have put the car battery in to test if the alarm siren is faulty.

Had a quote from MB and they say the siren is £101.

 

[Rupz911]

As promised I am providing an update to the problem.

So I had the problem happen a number of times again and it always seems to be after 5pm (dont ask why). I came back to my car to find the lights flashing and the battery drained, but still able to get start the car. Ive also realised that the battery is fine as it is charging as it should and when the car behaves itself, the voltage is stable. I have concluded that the issue is more than likely with the alarm siren box.

One thing i did find, which is either a coincidence or a possibility, is that then the lights are set on AUTO, there is a greater possibility of the interior lights/alarm going off/ lights flashing.

OK, so last night i took out the alarm from the car (located on driver side front wheel arch) which wasnt as difficult as i thought it would be. a No 8 spanner, a 12mm socket and you're good to go.

Going to leave the siren out for a week and see if there is still any issues before i open it and see what the damage is.

will keep you all posted.

 

[Major774]

I know the thread is old... But did you find the problem?

 

[E270 Owner]

looks like alarm unit as usual