Access to 2004 Audi A4 radio; purpose: connect USB/MP3 interface

What are the problems exactly. You are being to generic.

the "interface" is the wire supplied by the maker of your ipod to connect into the socket in the car.(here in Europe you have to buy a "parrot" to "interface with the radio for the phone as not all phones are compatible.)

I know you can that you can change this by simply hooking up a scan tool for specific year. There are language options accessible for situations like this. Here is a sample of what can be changed using VAG 5052 or equivalent scanners.

Coding

• 0?xxxxx: Model
  • 1 = Lamborghini
  • 2 = Audi A3 (8P)
  • 3 = Audi A4 (8E)
  • 4 = Audi A4 Cabriolet (8H)
  • 5 = Audi A6 (4B)
  • 6 = Audi TT (8J)
  • 7 = Audi R8 (42)
• 0x?xxxx: Treble Speaker Monitoring inactive
  • 0 = Front Treble Speaker Monitoring inactive active (NOT Audi A4 Cabriolet)
  • 1 = Front Treble Speaker Monitoring inactive inactive (ONLY Audi A4 Cabriolet)
• 0xx?xxx: Sound Characteristic
  • 0 = Sound Characteristic linear
  • 1 = Audi A4 (8E)
  • 2 = Audi A6 (4B)
  • 3 = Audi A4 Cabriolet (8H)
  • 4 = Audi TT (8J)
  • 5 = Audi A3 (8P)
  • 9 = Sound System
• 0xxx?xx: Telephone/Telematic
  • 1 = Telephone not installed (Remote Feed Voltage for Microphone active)
  • 2 = Base Plate (Temic - Remote Feed Voltage for Microphone inactive)
  • 3 = Base Plate (Cullmann - Remote Feed Voltage for Microphone inactive)
  • 4 = Base Plate (Nokia - Remote Feed Voltage for Microphone inactive)
  • 5 = Telematic Europa (Remote Feed Voltage for Microphone inactive)
  • 6 = Telematic US (Remote Feed Voltage for Microphone inactive)
  • 7 = Base Plate diagnostic capable with Comfort Control
• 0xxxx?x: Equipment I
  • 1 = Tuner not installed
  • 2 = Digital-Radio installed
  • 3 = Satellite-Radio installed
  • 4 = Satellite and Digital-Radio installed
  • 5 = Analog Input (AUX) installed
  • 7 = Satellite-Radio & Analog Input (AUX) installed
• 0xxxxx?: Equipment II
  • 1 = TV-Tuner/CD-Changer/Multi-Function Steering Wheel not installed
  • 2 = TV-Tuner installed
  • 3 = CD-Changer installed
  • 4 = TV-Tuner and CD-Changer installed
  • 5 = Multi-Function Steering Wheel installed
  • 6 = TV-Tuner and Multi-Function Steering Wheel installed
  • 7 = CD-Changer and Multi-Function Steering Wheel installed
  • 8 = TV-Tuner and CD-Changer and Multi-Function Steering Wheel installed
    
    

Adaptation Channel 001: Tire Circumference The tire circumference is beeing adapted in "mm".


Channel 002: Wheel Pulse The wheel pulse describes the amount of wheel pulses per revolution.
If value 0 is entered the system calibrates automatically itself after several kilometers and inputs a value.

• 43 = Audi A3 (8P) / Audi TT (8J)
• 45 = Audi A4 (8E)

Channel 003: Language (Screen)

• 0 = German
• 1 = English (UK)
• 2 = French
• 3 = Italian
• 5 = Spanish
• 6 = Portuguese
• 7 = English (UK)

Channel 004: Back-Up Camera

• 0 = Back-Up Camera not installed
• 2 = Back-Up Camera installed

Channel 005: Speed Threshold (Video Input)

• 0 = max. 0 kph or 0 mph
• 1 = max 5 kph (Standard for Europe)

Channel 007: Options Channel 008: Volume Characteristic Channel 010: Region

• 0 = Europe/North America
• 1 = Australia/South America
• 2 = South Africa

Channel 011: Language (Speech Recognition)

• 0 = German
• 1 = English
• 2 = French
• 3 = Italian
• 5 = Spanish

Channel 018: Start Screen The start screen setting has to correspond with the control module coding, e.g. a S3 start screen doesn't work with an A4 coding.

• 0 = Standard Start Screen
• 1 = Audi S3 Start Screen
• 2 = Audi S4 Start Screen
• 3 = Audi RS4 Start Screen
• 4 = Audi TT Start Screen
• 5 = Audi R8 Start Screen

Channel 065: Read Test Channel 066: Self Test Channel 067: CD/DVD Drive

• 000 - Normal/Eject-Button enabled
• 001 = Eject CD/DVD (will not be saved)
• 255 = Eject-Button disabled/locked (Anti-Theft-Protection)

Channel 068: Screen Test Values will not be saved, they only act as initiation for each Test Picture.

• 0 = No Test Picture
• 1 = Test Picture: Red
• 2 = Test Picture: Green
• 3 = Test Picture: Blue
• 4 = Test Picture: White
• 5 = Test Picture: Black
• 6 = Test Picture: Checkerboard
• 7 = Test Picture: Checkerboard (inverted)
• 8 = Test Picture: 64 Gray Scales (vertical Bars)
• 9 = Test Picture: Special

Channel 069: Display Mechanism

• 000 = Display closed
• 001 = Display open
• 200 = Display half open (Obstacle)
• 255 = Position undefined

Channel 070: Display Brightness

• 0 = 0% Brightness (Display OFF)
• 1 = 20% Brightness
• 2 = 40% Brightness
• 3 = 60% Brightness
• 4 = 80% Brightness
• 5 = 100% Brightness

Channel 099: Transport Mode Only applies to models without Gateway/Diagnostic Interface for Databus.

• 0 = Transport Mode inactive
• 1 = Transport Mode active

Channel 111: Reset

• To perform a system reset/restart save 1 as new value.

Channel 114: FM Frequency

• Range: 875...1080

Channel 117: Signal Test (Output)

• 0 = Fader Center & Balance Center
• 1 = Fader Front & Balance Left
• 2 = Fader Front & Balance Right
• 3 = Fader Rear & Balance Left
• 4 = Fader Rear & Balance Right

Channel 136: Driver Position

• RNS-E Basic
  • 03226 = Left-Hand-Drive (LHD)
  • 02632 = Right-Hand-Drive (RHD)
• RNS-E High/US
  • 00005 = Left-Hand-Drive (LHD)
  • 00013 = Right-Hand-Drive (RHD)

It is not in the vehicle , if you have the external cd changer,
the cd changer can be unplug, to install the auxiliary audio input,
this is what you need volswagen aux interface

for ipods use this ipod interface full ipod controls from the volkswagen radio

You just go to the link I attached I'm sure you will get the solution of your problem

2004 Audi A4 Workshop Repair Service Manual PDF Download

It must be turned clockwise while being pushed in. The local parts store will have a tool just for this purpose.

most of us techs write down the code after we instal the radio, in the owners manual in the radio section, however if you dont find it there tke copy of your title and registyation to an Aude delaer and they will be able 2 look for your code and instruction to recode your radio

Most of the OEM headunits and changers are made by common radio manufacturers. Visit http://www.crutchfield.com and contact them. They make adapters that will interface an aftermarket changer to your factory system. if you could get me a model number and any other info offf of the radio and the changer I will research adapters and which brands and models of changers will work.

Yes. I know of two units out there: Denison's IceLink, and the Phatnoise box (or Phatbox, as some call it). I believe both install the same way. You figure out where you want the iPod connector (say, glovebox). Pull the stereo out of the dash, disconnect the CD changer (you'll lose the changer function with these but who cares?), and plug the adapter cable into the changer's port. It'll allow the iPod to play through the factory stereo, and will allow you to control the iPod with the buttons on the factory stereo.

I have the same problem. Did you get anyone to help you? I have the same car. A4 1.8T 2005 with the Symphony factory radio.