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Discussion Starter · #1 · (Edited)
Hey Guys,

Anyone else feel like their FM radio reception not the best? Is our FM antenna strictly limited to the rear window defogger wires and the diversity antenna? My 2004 E60 has the little shark fin on the roof and has much better reception than my 2009 E63.

I'm reading a lot of guys blaming the diversity antenna on remote keys not working, my keys work fine. Does the diversity antenna have anything to do with the keys? Thought there were other antenna's for that?

Anyway, my main problem is FM radio receptions seems to be lacking. If I didn't have my E60 to compare against, I might never know, so its sort of subtle, but its there. Definitely has an impact on sound quality. As I pass different areas, can hear the sound quality fade in and out. Sure seems antenna type problem.

Good read over here on the E65 system. Interesting how the rear defogger wires have separate areas for different frequencies.


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Michael
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Rear windscreen / heater element serves both with a module above the windscreen in the middle , over time this breaks down, is one place, the other is within the front windscreen, think there is also a model in the boot lid for antenna. Clearly memory failing but this was a real problem back when in that they would have to replace the rear windscreen. BMW often refused even during warranty windows because of cost.
 

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The antenna in mine 645 is in the back of the trunk lid. The XM antenna is there also, it does not work well. BMW added another antenna to mine on the XM, & it still sux! I have not really had problems with my FM reception, so this is new to me.
 

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Discussion Starter · #5 ·

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Yea the FM is not great. Have you replaced any of your lighting with LEDs? They can cause noise that makes the FM a hard time with reception.
The in trunk antennas antennas leave a lot to be desired.
 

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You would think BMW would have put a little more thought in where the antennas were installed. My XM was so bad, that they could not even make it better, with a new system, & an antenna located on top of the car. It worked no better after 5k of their money.
 

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Discussion Starter · #8 ·
No lighting replaced that I am aware of, car has 38K miles on it, seems unlikely. I may have to bite the bullet and try the diversity anntena. or stick to CD's and AUX
 

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If your mobile phone reception is good when driving your normal route and you have AUX or a BT streaming mod, try one of the internet radio apps on your phone. Might be the easiest & cheapest way of listening to a radio station.
 

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The aux option for XM, or IHeart radio, would get much better reception on the car. This takes the antenna out of the solution, & get a better signal. There is a good CIC update in the DIY section if you want to go that way?
 

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Discussion Starter · #11 ·
Beginning to think the diversity antenna is located in left right C-pillar

This is picture of rear glass glass and location of diversity antenna:

This is picture of glass, and it appears to show connections for the diversity antenna

The C-pillar cover
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Discussion Starter · #12 ·
Finally pulled up the TIS on this, it is at rear left c-pillar.

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Discussion Starter · #14 · (Edited)
Rear windscreen / heater element serves both with a module above the windscreen in the middle , over time this breaks down, is one place, the other is within the front windscreen, think there is also a model in the boot lid for antenna. Clearly memory failing but this was a real problem back when in that they would have to replace the rear windscreen. BMW often refused even during warranty windows because of cost.
Interesting, was looking close at this this morning. Ran across this solution, Cadillacs having same issue: deville bad radio reception

Poor Radio Reception or Radio Static/Increased Interference with Rear Window Defogger On or Some Rear Window Defogger Grids

Poor Radio Reception or Radio Static/Increased Interference with Rear Window Defogger On or Some Rear Window Defogger Grids May Be Inoperative (Diagnose and Repair Rear Window Defogger Heating Grid) 1997-2001 Cadillac Catera
1997-2002 Cadillac Eldorado
1997-2004 Cadillac DeVille, Seville
2003-2004 Cadillac CTS


Condition

Some customers may comment that the radio has poor reception or radio static/increased interference when the rear window defogger is turned on. Also, some rear window defogger grids may be inoperative.
Cause

This condition may be due to microscopic cracks in the electrically heated grids of the rear window defogger. These cracks may cause electrical interference when the rear defogger is on and this could affect radio reception.
Background

The addition of vertical grid lines to the heated back window defogger circuits has made it difficult to detect broken defogger grid lines. In the past, it was a simple matter to use a voltmeter to check the continuity of each grid line in order to locate a non-functional line. New design back windows have two vertical grid lines that connect all of the horizontal grid lines together, thereby providing alternate routes for the electrical current to follow. This makes the old test method ineffective.
Materials Required



  • Permatex Quick Grid, P/N 15067, or equivalent
  • A small ball of fine steel wool Type 00, or
  • Optional -- A strip of liquid crystal heat sensitive paper, 51 mm x 305 mm (2 in x 12 in) or similar size (Contact Edmund Scientific at 800-728-6999 for part number CR30723-70 or go to www.scientificsonline.com), or
  • Optional -- A portable infrared thermometer, GE-46819, available from Kent-Moore (1-800-345-2233), or equivalent.
Correction

There are three distinct zones across the back window that must be checked. They are:


  • the driver's side outboard of the two vertical lines
  • the passenger side outboard of the two vertical lines
  • the central zone that falls between the two vertical lines
To detect a broken grid line in any of the above three zones and to isolate the exact location of the break, perform the following:


  1. Start the engine and turn on the back window defogger. Important

    The first place to check should be the driver side segment 2 to 3 lines up from the bottom about 380-385 mm (15-15.2 in) from the buss bar.

  2. Take the ball of fine steel wool and twist one end to a point. Move the point slowly across each grid line. Be sure to start at the far side of the zone and move it to the opposite side of the zone. When you bridge the grid line break with the steel wool, you will see a small spark. Repeat the test over the same area to be sure you have accurately located the break. Mark the exact location of the grid line break. Repeat this portion of the test for each grid line. If you do not see a spark at any point, it is possible that there are two breaks in the same line and zone. Close visual inspection using a magnifying glass may be the only way to locate breaks in this case.
  3. The following are provided as a alternative way to detect a non-functional grid line. If available, use in addition to the steel wool.
    1. Method using liquid crystal heat sensitive paper.
      1. Important

        The first part of the test must be completed quickly before the entire surface of the back window becomes warm.

      2. From outside the vehicle, place the heat sensitive paper (dull surface in contact with the glass) against the top driver side grid line. Start the engine and turn on the back window defogger. A distinct color change will take place at each conductive grid line. Repeat for the bottom grid lines until they have all been checked in the driver side zone.
      3. Repeat the process for the passenger side and center area zones.
      4. If no color change is noted for a grid line, place a crayon or china marker check mark beside it. Mark each grid line in the zone where it is non-conductive and therefore not heating up. More than one broken grid line may be found.
    2. Method using a portable infrared thermometer.
      1. Start the engine and turn on the rear back window defogger.
      2. From inside the vehicle, start at the top driver side grid line and slowly run the portable infrared thermometer vertically down the rear window contacting each grid line. You should be able to see a district variation in temperature readings.
      3. Mark each grid line in the zone where it is non-conductive and, therefore, not heating up. More than one broken grid line may be found.
      4. Repeat the process for the passenger side and center area zones.
  4. Use Permatex Quick Grid, P/N 15067, or equivalent, to repair each broken grid line. Follow the manufacturer's instructions.
  5. Wait 24 hours before turning the defogger on, or the repair can be fast cured using a heat gun, 260°C -- 371°C (500°F -- 700°F). Hold the heat gun within 25 - 51 mm (1- 2 in) from the repair point for 2 to 3 minutes.
  6. Recheck the grid line with the heat sensitive paper or a portable infrared thermometer to ensure that the line is now functional and that the repair was successful.
 

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Discussion Starter · #15 ·
I managed to get to Diversity Antenna and pulled out the connectors that attach to the rear window defogger - the physical antenna I presume. The 1st one I pulled didn't change reception much, the 2nd one, could hear a little static from time to time. So, now I'm confused. was assuming if both connections pulled there would be zero reception. So how does this thing really work? I know its suppossed to pick between 2 antenna's and decide which has best reception and feed that to the amp, but with both pulled, I assumed there would be zero reception??
 

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This would be a good question for Gary, as he knows the stereo problems with our cars. I still have XM issues, even after BMW changed the complete system out. They wound up putting on an external antenna on the top of the car, but it still sucks! This was the best they could do. Since I couldn't live with all of the problems, I just disconnected XM.
 

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Discussion Starter · #17 · (Edited)
Here are some shots for future reference. The white rivets are at the top of the C-pillar cover where it meets the headliner.
 

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Discussion Starter · #18 ·
This is the tool used to remove C-pillar cover. The plastic tools bent too much and could not get the job done. It was in there pretty tight.
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Discussion Starter · #19 ·
Well, this saga continued today. Took the M6 over for state inspection, so had a good chance to listen to radio today while driving. Unplugged one of the antenna feeds from the diversity antenna and kept the other plugged in. It sure "seemed" like reception was better. As if, now that the diversity antenna only has one choice and has no choice but to stick with it. I guess I need to put the other feed back in and repeat this test under same conditions. I "feel" like the diversity antenna may have been switching between the 2 antenna feeds and sometimes selecting the worse of the two. So maybe some of the intelligence in the DA is off, what ever the intelligence may be....... possibly some circuit that feeds a microprocessor, maybe the input to the uP is going out ??? I'm afraid this is as close as a debug test that I can get, don't have proper test equipment to really figure this out. I wonder if BMW does......
 

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Sounds like the AGC (automatic gain control) that switches between the two is off. But in this tech, that is all processor controlled and not manually controllable with a poti, like older descretic component electronic tech.
I cant recall, did you change the ccc unit? Fairly sure that has some of the tuner components and possibly the gain control.
 
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