A8 Parts Forum  

Go Back   A8 Parts Forum > A8 D2 > D2 - Sat Nav, ICE, Audio & TV

D2 - Sat Nav, ICE, Audio & TV All in car entertainment discussions

Reply
 
Thread Tools Display Modes
  #1  
Old 2nd February 2009, 04:26 PM
sutherland sutherland is offline
Member
 
Join Date: Feb 2009
Posts: 79
Default Radio Antenna Open Circuit - Radio or Antenna Problem?

I have perfect TV reception, but no FM. Have had the A8 in bits trying to find a fault in the antenna wiring, but nothing obvious.

VAG COM gives an 00856 Radio Antenna Open Circuit fault. Does this indicate an internal problem with the RNS unit itself rather than the antenna amplifier or antenna wiring?
Reply With Quote
  #2  
Old 2nd February 2009, 04:47 PM
IT's Avatar
IT IT is offline
Administrator
 
Join Date: Jan 2009
Location: Harrogate, North Yorkshire
Posts: 6,222
Default

Quote:
Originally Posted by sutherland View Post
I have perfect TV reception, but no FM. Have had the A8 in bits trying to find a fault in the antenna wiring, but nothing obvious.

VAG COM gives an 00856 Radio Antenna Open Circuit fault. Does this indicate an internal problem with the RNS unit itself rather than the antenna amplifier or antenna wiring?
Hi, it would be extremely rare for the RNS unit itself to be the cause of this fault, and indeed I personally doubt the rear antennas will be the cause either.

In our experience, we have seen a few cars with faulty FM, but perfect TV.

The 'interesting' thing is that they all use the same aerials on the rear screen.

They are fed through a diversity switcher which lives at the bottom of the D pillar trim, on the passenger side (UK).

To access it, you will need to the trim covering the D pillar.

You will see 4 aerials feeding into it, and a number of connections out. 4 of the outputs will go to your TV tuner in the boot. 2 other connections will supply the FM radio at the front of the car. There is a non-coax power connector too.

If i were you, I'd remove this unit and inspect the FM connections thoroughly. Typically, the tiny coax connections on it fail, and sometimes even break away from the board. It is probably possible with a little skill to resolder it back together though, which will save some expense.

Photo attached for reference....
Attached Thumbnails
Click image for larger version

Name:	diversity.JPG
Views:	1478
Size:	77.3 KB
ID:	32  
__________________
For parts enquiries and Forum User Administration please contact customer services directly, not me - enquiry@a8parts.co.uk, www.a8parts.co.uk, or call 01642 783537

The Daily Town Car - 2023 Tesla Model Y Performance. Black with Black. Giant ipad screen, huge sunroof, 4 wheel drive, Tow bar, lots of ooomph and made in China, so actually built properly unlike the Californian ones.

The Family Wagon - 2018 Tesla Model X. Black, 7 Seats, Towbar, Homelink, Enhanced Auto pilot with Summon and self park, Heated front seats, CCS Charger upgrade, MCU2 Upgrade, Falconwing Doors, Self opening / closing doors, Netflix, Spotify, toys, Air suspension, alcantara roof + lots of other stuff......

The 17 year old Driver Wagon 2015 Skoda Citigo Monte Carlo. Alloys, Power steering, Aircon, Leccy windows, Sat Nav, bluetooth, central locking, cup holders, 59 whole bhp. Million times better than my first car. Well jealous.....

The First 20 Audis:

2001 D2 4.2 QS Silver, 1997 D2 S8 Silver, 1999 D2 4.2 Silver, 2002 D2 S8 Dolphin Grey,
2003 C5 RS6 Blue, 1998 D2 S8 Black, 2000 D2 4.2 QS/S8 Ming Blue, 2003 D3 4.2 Ming Blue,
2005 B7 S4 Blue, 2006 D3 3.0 Tdi Black, 1999 D2 4.2 Silver, 2003 D3 4.2 LPG Crystal Blue,
2000 D2 S8 Silver, 2007 3.0 Tdi Q7 Black, 2009 B8 S4 Black, 1998 D2 S8 Agate Grey,
2006 D3 4.2 Tdi Blue, 2006 D3 S8, 2007 Q7 3.0 Tdi, 2006 C6 S6,

The Second 20 Audis:

2011 A7 Sline, 2001 A2 1.4 Tdi Black, 2002 A2 1.4 Tdi Silver, 2006 A8 4.2 Tdi Blue,
2007 4.2 Tdi Q7, 2006 S4 Cab Silver, 2010 RS6 Saloon Black , 2007 TT Roadster,
2010 A8 D4 4.2 Silver, 2006 C6 A6 2.7 Tdi Quattro, 2000 D2 4.2 QS/S8 Ming Blue (again), 2008 Q7 4.2 Black,
2009 C6 RS6 Saloon Daytona Grey, 2001 Fully Loaded A2 Tdi, 2006 Avant S6 Black, 2007 VW Caravelle Exec Black (almost an Audi)
2009 TT Roadster Daytona, 2015 Q7 4.2 tdi lava grey, 2002 GmbH D2 demonstrator, 2006 D3 A8 LWB 4.2 Tdi Black

Most Recent Audis:

2001 A2 1.4 Tdi Black, 2007 4.2 FSi Q7 ABT Blue, 2016 S5 Coupe Launch model, 2004 S4 B6 Cabriolet, 2016 Q7 Sline White, 2006 Q7 4.2 FSi Black, 2012 Q7 Sline+ 4.2Tdi White, 2008 Blue Audi S8

Everything Else

1989 Subaru Justy, 1986 Vauxhall Cartlton 2.0 GL, 1985 Vauxhall Carlton 2.2 CDi, 1987 Ford Sierra XR4x4, 1983 Vauxhall Senator, 1985 Vauxhall Senator 3.0i, 1997 Polo Saloon, 1997 Peugeot 306 1.9 TDi, Ford Sierra Sapphire 2000E, 1990 Subaru Justy, 2000 Subaru Impreza, 2000 Subaru Impreza RB5, 1993 Range Rover LSE, 2005 VW Bora, 2003 Skoda Superb, 2003 VW Passat V6 4 Motion, 1996 Peugeot 106, 2000 Range Rover 4.0, 2019 Tesla Model 3 Performance
Reply With Quote
  #3  
Old 2nd February 2009, 04:52 PM
sutherland sutherland is offline
Member
 
Join Date: Feb 2009
Posts: 79
Default

Thanks Ian, I have had the seats out and set eyes on that thing already. In fact, twiddling the antenna input did cause the hiss to change. I've done plenty soldering over the years, so I'll get the seats out again and get that little box opened up and inspected.

I'll let you know how I get on.
Reply With Quote
  #4  
Old 7th February 2009, 03:50 PM
sutherland sutherland is offline
Member
 
Join Date: Feb 2009
Posts: 79
Default

I eventually got to uncovering this box again and found that the main antenna connection (gold/brass thing) had become unsoldered. I managed to solder the little pin back down so I have reception again. The only problem that remains is a little bit of crackle and I think that is because the little wings (earth I guess) at the side of the connector were also soldered onto the board, but this is impossible to fix well with a conventional soldering iron. I don't know how it would have been done in the first place.

So this will do for the moment, but I'll try to pick up one of the diversity boxes in due course.

Thanks for your help Ian.
Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 10:47 PM.


Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.