Key programming issue

[ainarssems]

Just to make it clear, there are 2 parts of the key that are in no way linked to each other and can be mixed and moved from one key to another and each part/issue need to be tackled separately.

The part near the blade with immobiliser transponder do not use battery and is only used for engine. For pairing this part you need to connect to car over OBD using VCDS or another tool and log in the instrument cluster(or immobiliser on older cars with separate immo box) using security code before coding new keys. Audi tools will connect to their server and retrieve the login code and some aftermarket tools will calculate code for you but not sure if there is anything doing it for FL D2. I did have tool to do it for PF D2 and C5 A6, and paired extra keys and extra transponders for remote start, then sold it again.

The remote part with buttons and battery has nothing to do with engine starting and is for locking/unlocking and is also used to identify driver for seat, steering and mirror memory. These can be paired without VCDS or other tools using 2 keys for new remote, or just one key to resync the remote that has already been paired. I have bought used remotes on eBay before and paired to my S8 and A6. And also resynced already paired keys a few times, for some reason Q7 keeps losing sync quite often for missis, I think she is just inadvertently pushing remote buttons when it's in pocket or handbag and away from car.

For the immobiliser part it does not make much sense that it would loose sync and the resync again, there is no battery or buttons on it. And it is only powered and active when the coil on the car is activated and sends the signal to key, the key harnesses that signal to power itself and sends a reply. There used to be an issue with the coil wires for D2 where the contacts in the plugs would oxidise and and increase resistance reducing power transmitted and also reducing signal coming back. My S8 also sometimes had this issue not long after I bought it. Sometimes both keys would work, sometimes one and sometimes none. I think there is a bit of margin between keys how strong the signal needs to be. After I unplugge/plugged back in coil wires several times to clean the contacts and sprayed with contact cleaner and wiggled around both keys worked fine for many years.

http://www.audipages.com/Tech_Articl...rereplace.html