Well, after spouting off here many times about how my car has been "absolutly flawless", I found my first bug with the car.... With the on-slought of winter coming, tonight returning home from dinner I hit the rear window defroster (electric) and much to my suprise It created complete static on the radio. Turn off the defroster and the radio is fine. Turn it back on and the radio has complete static again. Very strange to say the least. So naturally before posting about it here I conducted a few tests... It only does it on F.M (all stations) not A.M... Does not do it when playing CD, or operating the nav. It does it while the engine is running or not, lights are on or off, front defroster on or off, etc..... It seems to be only effecting the F.M reception. Now I know this is only an inconvenience at best, but its quite puzzling isn't it???
The problem is surely nothing to go running to the dealer immediatly over, but will inform the service advisor of the problem during the 'C" service thats going to be done in another 2,200 miles....
I've never heard anyone report this problem to the forum before or did I miss something??? I know I've used the rear defroster in the past, but must have always been playing a CD, so I never caught it before.

B.T.W My wife gave me **** about rushing home to report it here...Had to laugh about that one.

 

Hi HOH

This is a strange one. I have searched through this forum and have not found any mentioned to this problem.

It has been very rainy in Southern California for this past week and I have dew on my car. So, for the first time I hit the defrost button while driving to work with my radio on --- STATIC. Static goes off once the defrost is off. I was completely baffled. I was wondering why after having the car for almost a year, I finally noticed this problem.

While at work, chatting with a co-worker about the W211 (he has one too), he mentioned that he was bummed because he noticed this STATIC problem over the weekend and took the car into the stealership....problem was with the built-in antenna on the rear glass.

Long story short, it appears that MB has had a manufacturing defect that affects the rear antenna when the defrost is on.

Really strange that this problem is noticed about the same time for some of us

 

HOH,

I don't know if it would be applicable to your car but for 03 W211's there was a TSB dealing with the problem of static when the rear defroster was on.

P-82_60-227 FEB 03 Audio System - Static Noise With Rear Defroster ON

 

I think it's normal because defroster is antenna.

 

I've only used the defroster a couple of times and had no problem. Maybe I had a CD playing though. I'll try it out today with FM on.

 

Is the antenna in the window? I've wondered whether it is in the window or in the NAV/Teleaid antenna. I seem to recall reading on one of these threads that there is an antenna for something in the bumper. I get a lot of multipath distortion on FM and have wondered if it is due to antenna placement.

 

I had this exact problem on a 2000 Caddy Deville, except when the rear def was turned on it caused complete silence on weak-ish FM stations & a sustantial loss of signal on the strong ones. It is due to a break in the defroster grid lines on the rear defroster. if you turn it on on a misty day there will be some localized area that will not defrost. The "leaking/radiating" current interferes/blanks out the FM signal going to the antenna. (If you look, you will see that the top 5 lines on the back glass grid are separate from the defroster grid below them. If they were defroster grid, the 2 vertical lines going thru the defroster grid would extend thru them too. On the Caddy, the top lines were the FM antenna.) My Caddys service dept manager wanted to get someone in to repair the grid, but my service advisor, who knew me ($) insisted on a replacement back glass. That cured it.The break(s) in the defroster grid can be anywhere within the part of the gridwork with the 2 vertical lines. The breaks in the grid can be microscopic or fairly visible when the lines are scanned by eye very slowly.

 

That would indeed be something if a FEB 03 TSB applies and your car was built FEB 04. Anyway sounds like it fits the bill. While in for repair you should also request that they apply TSB P-B-82.85/325b - April 04 basically it updates the audio gateway to the current AGW SW 49/03. Good luck. One question, did you at least hit the head before running over to the computer/forum?

 

The system is designed whereas the upper area of the rear window cannot be heated. The upper visible wires are not heating wires, but rather antenna wires.

 

Thanks.

 

This is interesting. According to my co-worker who had his '03 E320 worked on for this static issue, the rear glass was replaced because of "broken or unconnected leads" for the built-in antenna. Nothing was mentioned software upgrades to the audio gateway.

 

I tried mine this afternoon and had no problem - no noise on FM, AM or anthing else. What's odd to me is that it affects the FM. Usually, electrical interference affects amplitude, not frequency, which is why electrical storms cause static on AM but not FM. But, EMI can act in strange ways some times. Good luck with it.

 

Thanks for that info DaveFr... And thanks to the rest of you that have responded to the question about my "bug"....

I think you have the makings of a service advisor...

Glad to hear it...

This is exactly why I never found this any earlier... Hell I've owned the car for over 7 months now....

Naturally.... My one finger typing would never allow it!!!!


Exactly what does this update do and what is the fix??? Is it something down loaded from a computer or does it require some grease monkey raping the wiring system in my ride....


************************************************** ******

Guess Ill be wanting to get to the bottom of this, but if it means replacing the rear window i'm going to let it go... everyone knows once a window is replaced there never the same....

 

Believe it or don't, there's also a service bulletin about crackling in certain radio modes due to insufficient grounding of the audio gateway. Electromagnetic interference can then cause bad sound. Test is to check the impedence of the frame mounting; if it exceeds a certain value (1/2 ohm I believe) then ground the frame better by removing some of the insulation.

-s-

 

HOH,

Thanks for the intel. I'm gonna check it out tomorrow morning on my L.A. area 2003 E-500 also to see if the static appears. I haven't had the need to check before as the car is usually garaged.

Thanks for the head's up! Either way I'll report here and schedule a trip MB Laguna Niguel. They may not be eager to see me, last time I had one of their C-class loaner cars, some Newport Beach 25 year old ditz with no insurance, and only a paper license (temporary DMV), and who hadn't yet registered the 1988 Honda she only bought a few weeks prior (she moved out here from Mass.) rear-ended me in front of the Dana Point Post Office.

I'm pretty sure MB won't want to lend me another loaner, lol!

Thanks again!

EDJ

 

Are you sure about this?

There is a TSB that activates those wires so that they do defrost the window:

P-67_29-10 APR 04 A/C - Rear Window Won't Heat in the Upper Area

 

So there’s no misunderstanding here, TSB P-B-82.85/325b does not relate to HOH defroster interference. I am recommending it as an additional application so he has the latest AGW software (April 04) in addition to fixing his defroster problem.

 

I understand they have to disengage the entire dash access to the upper interior fire wall is needed. Not to worry, it is a computer update which should not cause any adverse conditions to fit and finish. This TSB fixes a number of things but more importantly if you do not have any of the problems addressed it underlines that you’re entitled to the new AGW software regardless. What’s the point, more than likely the new AGW improves upon the old even if you do not have the addressed symptoms and therefore why not upgrade.

TSB P-B-82.85/325b Audio System Intermittently Not Functioning corrects; HU locks up, HU resets, black screen, static noise from speakers, STAR after start up, and intermittent audio.

If you decide to mention it and want a copy forward your email address through PM.

 

Positive! P-B-67.29/10 (April 19, 2004) simply explains the design of the system if the customer reports the rear window cannot be heated in the upper area. It does not, and cannot activate the upper visible antenna wires they are not heating wires.

 

One thing, unfortunately one would expend more energy trying to get the service dept. to understand this than would actually go into applying the fix.

 

Yeah you are right, someone here mentioned earlier this was a fix.. The TSB just is to inform customers about what you stated..

 

So what’s the verdict? Any progress?

 

Oh ye of little faith

Regards,
John
Looks like a wet morning in Torquay (again)
(My grass has now finally returned to its proper shade of green!)

 

Sorry, no progress to report. This is hardly worth a "special" 75 mile round trip to the dealer... I'm going to wait when the "C" service is done in another 2000 miles....

 

Dealer has informed me that in order to fix the static problem described, they need to replace the rear window glass...
This is due to a broken heating element in the glass that will generate interference when the radio is operated at the same time the rear defrosters are turned on....

I was handed the following star buletin (DTB)...
Order number : P-B-82.60/227
Dated february 26 2003
Group 82
Subject Model 211 Radio interference
Damage code 67101 74
Operation number 67 5045
Est time to fix 3.3 hrs
Rear Glass part numbers are (if interested)... Green 211 670 03 80
Blue 211 670 01 80

They were pretty adamate about getting me to agree to replace the rear glass immediatly, but told them I'll wait and think about it....The static is not bothering me and the rear defrosters are working great, so I'll wait and see.... B.T.W.... I purchased the extended warranty so I have over 6 years left to make up my mind...