No AM on symphony stereo

[macman71]

vag com?? do you mean computer with diagnostic software?? Sorry to be a dunce but only just started posting, need to get up to speed with you guys. Also by base unit do you mean what you can see on the roof - or is the base unit hidden away within the roof / lining?

Appreciate your help (and patience). Sea or course?

[a8 tech]

If you follow the aerial antenna down to the bottom you will see it screws into the base.
This base unit fails on the am reception.
VAG COM is diagnostic software which helps the user indentify faults.
union or league

[macman71]

Thanks for the reply.......thought as much.
I was actually thinking of renewing the "aerial assembly" for a BMW type fin aerial. Thought it might be more robust and less exposed? Can this be done? Any thoughts?

Union born and bred

[djl78]

Ok ill help you.
If you have vag com you can check the coax and aerial base in measured value blocks.
If not its 75% roof aerial base unit defectie as the am side fails whilst the fm is ok.
I fish therefore im a lazy sports man

a8tech ,
Could explain in a little more detail how to check measured value blocks for the aerial please.I have genuine vag com but am fairly new to the game.
Thanks
djl

[a8 tech]

Look at measured value block 3 componant,this will indicate if the aerial is open circuit or short to earth.
I tend to find the block indicates short to earth as the coax cable breaks but the base (in the roof where the antenna screws in)is a common failure.
; VAG-COM Label File
;
; Audi A4 (8D)
;
; Component: R - Radio (#56) Generation I
;
; P/N: 8D0-035-1??-???
;
; includes measuring blocks, adaptation and coding
;
; This file is part of a redirection package,
; make sure you have all of the following files.
;
; 8D-56.LBL
; 8D0-035-1xx-56.LBL
;
; created on 25/Apr/2007 by Sebastian Stange (Sebastian@Ross-Tech.com)
;
; last modification: 25/Apr/2007
;
; requires VAG-COM 701.0 or newer
;
;
;---------------------------------------------------
;
; measuring blocks
;
;---------------------------------------------------
;
;
001,0,General
001,1,Speed Signal,recognized
001,2,Supply Voltage,(Terminal 30)
001,3,Illumination,(Terminal 58d)
001,4,Status,S-Contact,Range: ON/OFF
;
002,0,Speaker/Line-Out
002,1,Location/Type
002,2,Status
002,3,Location/Type
002,4,Status
;
003,0,Antenna
003,1,Antenna Type
003,2,Component
003,3,Status
;
004,0,General
004,1,Amplifier,Output,0 = OK\n1 = Short to Ground
004,3,Telephone
004,4,Telephone,Mute Status,Range: ON/OFF
;
005,0,Communication Status CD-Changer (R41)
005,1,CD-Changer (R41)
005,2,Status
;
006,0,External Display
006,1,External Display
006,2,Status,,Specification: OK/n.OK
;
007,0,Steering Wheel Control
007,1,Steering Wheel,Buttons
;
;
;---------------------------------------------------
;
; coding
;
;---------------------------------------------------
;
;
C00,Radio (R) Coding
C01,00?xx: Speakers
C02,0 = Sound System (No passive Speakers)
C03,1 = 1 passive Speaker (Front Left for Bose Sound System with Telephone)
C04,2 = 2 passive Speakers (Front) and 2 active Speakers (Rear)
C05,5 = 2 passive Speakers (Front) and no active Speakers (Rear)
C06,00x?x: Sound System Correction
C07,0 = No Sound System (No Correction)
C08,1 = Sound System (Bose)
C09,00xx?: Configuration
C10,+1 = Active/Remote Supplied Antenna
C11,+2 = CD-Changer
C12,+4 = Secondary Display (Board Computer/Navigation)
;

[djl78]

Thanks for the reply.Incidentally i have an a6 allroad c5 chassis.I checked group 3 in measured blocks and everything seems fine.
I also gained access to the diversity box under the headlining to make sure there was supply voltage which there is (12v).
I also checked the main coax cable coming from radio by inserting a very thin wire into it,hey presto i got am loud and clear.
I removed the aerial base and it appears the the cable is slightly chaffed and the wires underneath are visible.Would that affect the operation?
So am i right in assuming that it's either the diversity box or the aerial itself?
Thanks again..
djl

[a8 tech]

measured value checks DC supply but not the the frequency so check the continuity.Also you can check the reception by pressing the station 1 button when you turn the radio on until the test mode comes on then press tone three times.
The last two digits of the lower line show the dbuv level.(concert and chorus)
For symphony press stsion button 1 when turning on until the test mode comes on

[djl78]

My better half has a 9N polo and i'm thinking maybe it would be possible to slave in the aerial off that before i plunge into buying another one from Audi.
No doubt the connectors will be different but it's worth a try i guess.

Thanks again for your help,very much appreciated.
djl

[djl78]

measured value checks DC supply but not the the frequency so check the continuity.Also you can check the reception by pressing the station 1 button when you turn the radio on until the test mode comes on then press tone three times.
The last two digits of the lower line show the dbuv level.(concert and chorus)
For symphony press station button 1 when turning on until the test mode comes on

I've tried the test mode,didn't know that existed..,and i get the following on the screen..
AM1 693
693 07 00 00 00
Means nothing to me...
I wasn't sure how to check the continuity of the aerial with a multimeter but what i did do was check between the bit where the aerial screws in and the outer section of plug where it connects to div box but i didn't get continuity.

[a8 tech]

I tried mine on the way home.
am talksport 693 07 00 00 50 i was getting xxx xx xx xx 42 to xxx xx xx xx 50
My am signal is fine so if your getting 693 07 00 00 00 you have no reception.
Swap the base from the polo if ot fits or bypass the div box if possible.
I have all the different coax attatchments and a spare base to do this as its sometimes the only way to eliminate and trace the fault.
When using the service mode try driving the car and see if the signal changes to eliminate outside interferance.Regards A8