AUDI A8 BOSE AMPLIFER REPAIR SERVICE 4E0 035 223 G / J


International postal repair service for Bose car amplifiers



This 10 channel DSP amplifier can be found in all variants of Audi A8  from 2008 onwards. It’s easily identifiable as being fitted to the car as the speaker grilles have the ‘Bose’ emblem on them. Each channel has a max 40 watt output, the sub-woofer output rated at 80 watts (4 ohm). The total max output is 360 watts.

There are two variant of this unit – a 2G system and 3G – they are not interchangeable – also the suffix A B C ect. relates to the revision of the unit – notably the later are prone to complete unrepairable failure – the circuit boards on these units are a blue colour – early ones are green.

The unit is similar to the Audi TT amplifier with the addition of a fibre optic (MOST) signal input stage ie. sound is transferred to the unit using fibre optic light and not copper wire. The switching on/off function is also controlled by light/fibre – often a common complain is the amplifier not switching off and causing battery drain.

With over 800 units repaired to date .. we are confident of having a 95% success rate.

Coding

These units are ‘paired’ or component protected to the original vehicle – so simply swapping one over will result in only one operation channel .The reason for this is down to Audi protecting the modules of each car – the VIN number of the car is stored in the amplifier module – when the unit is being recoded the VIN number is compared online against a database of blacklisted VIN numbers , coding can not proceed if there is a match,rendering the unit useless.

Coding can only be achieved using VAS or ODIS which is an online system that logs on the the factory system

What Fails and Why

With many of these cars there is a problem with water ingress –  Although with the A8 it’s usually down to an overheating issue with the board – very often it may be necessary to recode the unit to regain full function of the unit. Also with this model it’s worth looping out the bluetooth handsfree module – especially if there is an issue with intermittent mute of audio .

The amplifier usually shows signs of water damage which can be moderate to severe – this causes problems with

  • no sound
  • draining battery
  • no mmi screen
  • random component protect
  • loss of channels

Other issues are – complete failure , this is often down to electrical surge which damages the delicate components within the amplifier – occasionally they can be non-repairable.

THE AUDI A8 BOSE AMPLIFIER

2006 to 2015 Audi Bose Amplifier

Models We Repair

  • 4E0 035 223 A or 4E0035223A
  • 4E0 035 223 B or 4E0035223B
  • 4E0 035 223 C or 4E0035223C
  • 4E0 035 223 D or 4E0035223D
  • 4E0 035 223 E or 4E0035223E
  • 4E0 035 223 F or 4E0035223F
  • 4E0 035 223 G or 4E0035223G
  • 4E0 035 223 J or 4E0035223J



Our Repair process

First of all the unit is disassembled and inspected and also electrically tested on our jig. The board is then cleaned of all corrosion and the factory applied protective coating is removed. The board is inspected in closer detail.

We use factory sourced production line components to ensure the sound quality is as precise as a Bose should be.

Finally, once assembled – the unit is check on a fibre optic test bench

Lastly we coat the unit with a hard plastic sealer – we do this to protect the circuit board and modules , this won’t make the unit completely waterproof  but it does give the delicate parts excellent protection against water / salt.

We recommend locating and fixing your leak before refitting – warranty will be invalid if the unit suffers further water damage.



What We Can’t Repair

Occasionally we see units that are beyond repair , this happens when one or more of the components fails causing damage to the processor and logic circuits – although repair would be possible at more expense , the unit would require VIN coding and would reprogramming – a replacement is the better option here – we can help you source one from one of our partners.

The rebuilt unit comes with a 6 Month extendable warranty – further water damage will invalidate this


Removal Instructions

Removal of this unit is quite complex and requires

  • Trim removal tool
  • T30 Torx
  • Long nose pliers
  • 8mm Nut spinner
  • 10mm Nut spinner

The unit is located in the rear of the car on the right hand side – Europe and USA

  

Find Your Model Number

Model numbers are usually located on the underside of the amplifier.