2001 A4 1.8t

[Tony Hoffman]

Sometime around the 2000MY VAG radios have non-volitale memory built into
them. However, they do interface with the body control module, so if you
swap them to another car, you need the code.

As for the older cars, I took an old lighter socket plug in and hooked it up
to a 9V battery plug, when I plug this into the lighter it's enough power to
keep the memories for a battery swap.

Tony


 There is something like that.  On me '99 bug (300+K km) I've done the
> throttle body alignment once, then it didn't need it, just the radio needed
> recoding.  On me Y2K bug (155+K km) even the radio does not need recoding.
> I imagine the Immobilizer recognizes its modules and lets them work.