I have a twelve month old A8 4.2TDI, during the day the illumination on the clocks (seedo + rev) fade to darkness and then back to full brightness when I go through shaded areas, under trees etc. This happens if the headlight switch is turned to auto or off and I'm being told by my local Audi centre this is normal, it is a way of indicating to the driver that he may need to turn his lights on!! Very annoying and distracting whilst driving, any help would be much appreciated.

 

Ifyou have access to Vag-Com you can try this:

Initial Steps:
[ul][*]Plug the VAG-COM device into the vehicle[*]Turn ignition key to 'ON' (do not start engine)[*]Start up the VAG-COM software[*]Click on 'Autoscan'. This will take you to another screen.[*]Click on 'Gateway installation list'. This will scan your vehicle to determine what 'gateways' are available and whether they have any Diagnostic Trouble Codes. Any items listed in red after the scan have trouble codes. Make note of what the codes are for each red item, and return to the Gateway Installation List screen. If there are no red items (items with DTCs), then don't worry, just proceed on with your coding.[*]Click on 'Clear all DTCs' and follow the prompts.[*]Proceed on with desired item below.... [/ul]


Recode Instrument Lighting to be 'Always On':
Follow 'Initial Steps', above, then...
[ul][*]Click on '17-Instruments'[*]When you go into this module, it will scan for fault codes and go straight to a fault code screen. It should say 'No Fault Codes Found'. Click the 'Done, go back' button to get to the main screen for this module.[*]Click 'Recode - 07'[*]Make note of your original coding.[*]Hover over the code with the mouse pointer, and it will show a pop-up balloon with information about the various digits of the code. It may or may not explain the rightmost digit.[*]One of the digits (the one fartherest to the right) is for the instrument cluster backlighting configuration. It's originally set at '3' (for the US models). You will change it to '4' (Pointers and scales ON, with Dimming Feature). For example, change 0004203 to 0004204.[*]Change this value in 'Software Coding___'[*]Click 'Do It!'[*]Click 'Close Controller, Go Back'


[blockquote]Note: By doing this, you have now set both the pointers and number scales in the instrument cluster to be on at all times rather than being sensitive to ambient light with the photosensor. The reason for the factory setting is to provide a visual cue that you need to turn on your headlights. Having the instruments lit all the time defeats this. Do this mod at your own risk. FYI - the photosensor is the almost invisible circle on the speedometer face right at the high end of the scale. [/blockquote][/ul]