mxseven

I just bought a 2001 A6, 2.7T, 6 Speed with immobilizer. I got one switchblade key that works, and a 2nd key that is already cut, but not programmed to work with immoblizer. I was told I just needed to go to the dealer to get it done. The 2nd key looks nearly identical except for slightly updated buttons, and the part numbers are identical on both fobs-- 4D0.837.23E

The first key works perfectly, and the second key will start and run the car, but the immobilizer light blinks constantly.

I went to the dealer to get the 2nd one working correctly. They tried, but it didn't work and they said it looked like an "eBay key", and that it would not accept programming. Luckily, they didn't charge me, and basically said I would have to get the correct fob, swap the cut key into it and bring it back for programming. I would have shown them that the part numbers matched, but I didn't compare them until after I left the dealer.

Ive done a bunch of searching but haven't found the answer. What gives?

Boston Driver

...his price is actually VERY good!

mxseven

It's seeming like I will have to get a new key, but can someone humor me and explain why my 2nd key with the same part number doesn't work? Could it simply be defective? Thanks.

Boston Driver

...perhaps a defective chip in the remote. However, having no expertise in the chip or the key, I am just guessing.

EuroVWGTi

what are the part numbers for all the keys for 2002-2004 a6?

im_cecil

If the seller gave you a used fob with a cut key, that's the problem. You'll need a new keyfob half with a new chip in it. The fob is 2 pieces -- one with the buttons which are reusable and one with the chip which is not.

mxseven

Aha! Thanks for the info. Makes a ton of sense now...