Dear forum readers,
I have my audi a4 b7 avant 2.0 tfsi for over 10 years now and am very pleased with it. When i recently wanted to borrow it out and gave the people the spare key they found out that it was not synched with the car anymore... Annoying but something which was easily fixed when i took the working key and did the sequence to activate the key again. I told them to use the key in the door but than the alarm went of and they were unable to stop it.
Something i found out then was that mannualy turning the key in the door does unlock all the doors (so central lock is working) but my alarm and the ignition blocker doesn't get disabled.

Does anyone have an idea how to fix this? the car does notice that the key is turned because it unlocks all doors but does not disable the alarm.
Is it one of those peskie little microswitches in the lock? I am quite a DIYer and not affraid to open up the door/lock. Just like to start with an autoption knowing what i need or what to look for.

Changing the whole lock is also an option but that i would rather only do if there is no other way.