Checklist for replacing Head Unit.

audifan said:
That is part of the issue, new owner and little knowledge of how the head unit swap was carried out Ian. Does the aftermarket have RCA? Was it adapted by chopping off the RCA plugs.
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Yes, but a picture of the wiring will probably reveal all. There is no direct connection to the speakers from the HU, so unless the whole thing has been rewired with new looms from HU to speakers there is little chance that the speakers are blown.

Ian
 
Kleynie said:
Yes, but a picture of the wiring will probably reveal all. There is no direct connection to the speakers from the HU, so unless the whole thing has been rewired with new looms from HU to speakers there is little chance that the speakers are blown.

Ian
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I’ll get some Kenwood keys and take a peak behind the HU to see what horrors await ?
 
Erlingtheelder said:
Though there is a ‘network’ of VCDS ‘heroes’ who may be able to help you with this craving you needing to have the above.
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Amazing, definitely will need some help. Just need to take the Kenwood HU and hope the destruction behind isn’t too bad. I don’t hold out too much hope though.
 
audifan said:
No real difference to the head unit just enables the Bose system. Look identical in the dash and hopefully all your wiring still exists.
The word BOSE appears on the display and this lives in the boot....


View attachment 73920

It may look different for 2 main reasons. One the disc mounted cd changer that you can see is mounted in a different boot side panel and the black piece over the battery with the triangular cut out is a spare wheel carrying bracket again was optional. Both unlikely to be fitted to your car. But can be upgraded to have these items.

The other difference with Bose cars is that the tool kit that is normally located in the boot is relocated to under the drivers floor.
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Good news, I have the Bose in the boot

8849C05D-A74F-4A99-A92C-90F455AC170B.jpeg
 
Hi @TheWelshWonder,

A few posts back @Erlingtheelder mentioned the Free Scan Register but it would have been better to post this direct link.

Free Scan Register

This is a register of members who generously offer free scans for other members. To arrange a free scan: 1. Click the pdf map in the footer and choose a location. 2. Cross reference the location number in the table below to identify the member. 3. Click on their username on the left, click...
www.a2oc.net www.a2oc.net

In general there is no intention that members who offer a free fault scan can also offer further VCDS expertise, indeed many will not have the experiece but others will and be prepared to help with your Bose VCDS coding, so worth a PM. You are lucky there is a register member quite close to you who I suspect can help.

On other things ....

I have near zero knowledge of electrics but I think you can go ahead and reinstall an OEM head unit (with extras) and it will work but not to its full Bose quality until tweeked with VCDS, so don't hold back.

On a trivial point, it is good your battery has a positive terminal cover but it is not an A2 part, I know I need one as well!

Andy
 
Andrew said:
Hi @TheWelshWonder,

A few posts back @Erlingtheelder mentioned the Free Scan Register but it would have been better to post this direct link.

Free Scan Register

This is a register of members who generously offer free scans for other members. To arrange a free scan: 1. Click the pdf map in the footer and choose a location. 2. Cross reference the location number in the table below to identify the member. 3. Click on their username on the left, click...
www.a2oc.net www.a2oc.net

In general there is no intention that members who offer a free fault scan can also offer further VCDS expertise, indeed many will not have the experiece but others will and be prepared to help with your Bose VCDS coding, so worth a PM. You are lucky there is a register member quite close to you who I suspect can help.

On other things ....

I have near zero knowledge of electrics but I think you can go ahead and reinstall an OEM head unit (with extras) and it will work but not to its full Bose quality until tweeked with VCDS, so don't hold back.

On a trivial point, it is good your battery has a positive terminal cover but it is not an A2 part, I know I need one as well!

Andy
Click to expand...

thanks Andy, I assume you mean @PaulA2 down the road in Westbury ?

Complete newbie to all of this, so all this help and support is great.
 
Kleynie said:
Well, I would say your head unit is most likely wired correctly, but we would still need a photo to confirm and to see what has been butchered.

Ian
Click to expand...

that joy will have to wait for the weekend or whenever I get the keys to take the HU out. I’ll be sure to post the result on here for you all to ‘enjoy’ ?
 
IIRC, there is not much to adapt with VCDS other than the BOSE start up logo and relevant auxillaries, such as MFSW and CD changer if present. The main thing being the connection of bose- pin to ground. This enables the internal settings according to Audi which is adjusted to the corresponding bose amp and disabling the internal amps.
So bose pin and you should be fine with whatever gen.2 audi radio you should choose. There is one other thing that could affect the response and that would be to choose for the A8/A2 setting, rather than 00 or another vehicle type available. But that's marginal.

Goodluck with your retrofit, in my opinion the best looking radio for our alu bullits. On top of that it generates a quite linear signal without much distortion, so ideal for amplifying ! ???

Here are the settings to be had:
Coding
  • ?xxxx: Options
    • +1 = Front Speaker Diagnosis inactive (ONLY Audi A4 Cabriolet)
  • x?xxx: Tone Characteristics (< MY 2001)
    • 0 = Linear Tone Characteristics (All Radios)
  • x?xxx: Tone Characteristics (MY 2002 >)
    • 0 = Tone Characteristics for all other Models and all Radio Chorus
    • 1 = Tone Characteristics for A4 (8E)
    • 2 = Tone Characteristics for A6 (4B) & Audi A2 (MY 2005 >)
    • 3 = Tone Characteristics for A4 Cabriolet (8H)
    • 4 = Tone Characteristics for TT (8N)
    • 5 = Tone Characteristics for A3 (8L)
  • xx?xx: Fader/BOSE/Amplifier
    • +1 = Fader-Display OFF
    • +2 = BOSE-Display ON
    • +4 = Mute Amplifier when using Phone
  • 0xxxx?x: Installation Options I
    • +1 = Navigation installed
    • +2 = Telephone installed
    • +4 = Voice Control installed
  • 0xxxxx?: Installation Options II
    • +1 = Diversity Antenna installed
    • +2 = CD-Changer installed
    • +4 = Multifunction Steering Wheel installed

NOTE: To Activate the Speed Display, press and hold the MENU button on the radio while turning it on. To deactivate it, cycle power.



Adaptation
Channel 04: Volume
Channel 05: Signal Position
  • 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 55: External Tuner
  • +1 = Satellite Tuner (SDARS) installed
  • +2 = Digital Radio Tuner (DAB) installed
Channel 66: GALA
  • 0 = GALA active
  • 1 = GALA inactive (or Bose Audio Pilot installed)
Channel 88: Long-Wave Band
  • 0 = Long-Wave Band active
  • 1 = Long-Wave Band inactive
Channel 99: Transport Mode
  • 0 = Transport Mode inactive
  • 1 = Transport Mode active
 
Tone characteristics '0' gives a flat audio response good for use with external dsp and aftermarket amplifiers. All other give the most bang for sound according to the audi engineers for the given Audi type . ?
 
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