This unit only requires plugs to operate – one main black plug which carries power and speaker out and also a smaller plug which carries the fibre optic data ( mmi signal ). Common problems when refitting are listed below, we will explore them in detail further on.
MMI screen still only displays for 2 seconds and shuts off
Sound from one side of the car only
‘System Initialising’ displayed
Still draining car battery
MMI but no sound
Unit shuts down when hot
No sound – Navigation sound working
** NEW ** DIAGNOSTIC FLOWCHART
**** A FIBRE OPTIC LOOP IS NOT THE ” BE ALL AND END ” ALL FOR TESTING ****
Please follow this flowchart when troubleshooting … we hear everyday ‘ the amps still faulty ‘ – by garages / mechanics who really don’t know how to troubleshoot properly , this often results in time wasted sending the unit back for us to test .. also an unnecessary expense .
Due to the rising costs of shipping – we are now in a position where we WILL have to charge for shipping if we get a unit back and it proves to be functioning correctly ….. take the time and follow all the steps .
MMI STILL SHUTS DOWN
This issue is usually down to either no power to the unit , people sometimes remove the fuse to stop the battery draining – and forget to replace it . It my also be the case that another MMI module may also be damaged . This is common on A6/Q7 models where the tuner or navigation drive can also be water damaged – we can repair both if required.
To check other units are ok – read the ‘ Loop MMI system ‘ section.
To check there is power to the unit you will require a voltage tester and also a remote control ( any TV or Hifi remote )
Remove the main black power plug – look at the left of the connector face on and you will see two terminals which are larger than the rest – these are the 12v positive and earth terminals – we suggest when your using a tester probe that a small piece of wire is inserted first to avoid ‘opening up’ the internal spade connector.
Another way of testing power is to unplug the fibre optic in/out plug (two orange wires) and use a light source or ideally a remote control – with the unit powered up point the remote at the socket on the amp and press a button on the remote – you should see a red light flash back at you. If there’s no red light , it will most likely be due to no power getting to the amplifier.
Occasionally we also find that someone has take the fibre cables from the connector and replaced them incorrectly – details are on this page.
A5 FUSE LOCATION
Check this fuse , it may be blown – also check the 12v power to this fuse ‘ rail ‘ .. often there is a wiring issue when the amplifier goes short circuit.
MAIN PLUG POWER CHECK ( ALL )
Check for power carefully on this point .. use a small piece of wire and insert into socket to avoid ‘ socket claws ‘ being distorted.
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SOUND FROM ONE SIDE OF VEHICLE (PASSENGERS SIDE ONLY)
This can happens for three reasons only – either the balance has been adjusted to one side .. or most commonly we find that the unit has been replaced previously and hasn’t been coded – this triggers ‘component protection’ and will allow the unit to function from one channel only. The best way to test this is to diagnostically scan the car and check the ‘ amplifier module ‘ section – it will probably report ‘coding error’ . To rectify this you will need to use ODIS or VAS to ‘pair’ the unit back to the vehicle. VCDS or ROSSTECH is not able to remove component protection.
Occasionally a badly water damaged unit may have corrupt data after repair – due to it being encrypted data , the only solution is to recode the unit. Also previous attempts at repair may also lead to VIN data being lost or corrupted.
Also , if someone has tried to ‘ code ‘ another unit to the car – the previous coding details are erased – hence the original correct unit will then need ‘ paired ‘.
This is usually caused by the tuner unit (underneath amplifier ) , which will have a data processing or programming error.. This will need to be sent to us for repair.
BATTERY STILL DRAINING
This is usually down to another module in the system keeping the amplifier ‘alive’ or triggering it on at random intervals …. normally this is down to a faulty tuner or nav unit – the driver control panel may also have been water damaged causing this – the best solution for checking if it’s the amplifier or a further module is to unplug the fibre in/out connector from the amplifier (small two orange cables) – leaving the main power plug connected… and leave the unit in the car for a day or so … if the battery still drains then there is a further issue with the amplifier – if not – then it’s another module.
NO SOUND - ONLY NAVIGATION AUDIO
When finding that you have no sound , but do have MMI display – check the voice navigation feature ,if you get audio then the following solution is relevant, you may also be able to complete a speaker test using appropriate diagnostic tool.
Common complaints which are , no cd function ( on pause ) , no radio sound , mute in the display are all connected to the MMI controller needing reset .. basically the control unit still thinks there is an issue with the amplifier unit . The only way to resolve this is to use diagnostic software to clear all the errors on the car , the more advanced software the better ie. VCDS / ROSSTECH – ODIS – VAS ect.
The amplifier is the only module which drives the speakers – so if you get at least navigation audio then this rules out the amplifier as being the cause of no sound.
MMI BUT NO SOUND
Most of the time this is due to the control panel being damaged by liquid – as the cup holder is close by – sudden braking or movement can spill any coffee or liquid from a cup , over the controls causing ‘control’ issues.
Occasionally we find the main MMI control module is faulty – this will probably be the case if you can’t switch OFF the ‘ mute ‘ symbol on the MMI display – if changed this will need to be coded on replacement or there will be no sound – it’s worth checking the coding status of this before replacing.
If in doubt – send the unit up to us to recheck.
Check the connector that plugs into the bass speaker (in the boot) … they can corrode due to water in the boot area.
UNIT SHUTS DOWN WHEN HOT
Check the fan is not obstructed and is free to spin .. it’s important to be aware that the fan only triggers when the unit is hot (above 55C ) and doesn’t run all the time.
It can also be down to the fan plug not sitting correctly in it’s socket – it can sometimes be displaced in transit.
Removal of this unit is quite complex and requires
Trim removal tool
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.