VWs require a VAGCOM to scan them, find how the dealer charges to scan, its your best bet,
Best money I ever spent on my 03 TDI Golf was Ross-Tech. $250 (my car) sets you up for anything (virtually) they can do at the shop. I've most certainly returned my initial cost back in money saved by resetting my own codes and work that I've done on the car - including changing the timing belt/re-timing the engine (most done by itself but you need the computer to check where you end up.)
I think its Parts Place who advocates buying the ebay sourced "knock off dongle" which you can use with the free download from Ross Tech. Some chinese version of the dongle, I think, and runs around $80. See the parts place online catalog. No service back-up from Ross Tech, however. (Duh!) I had some doubts about full functionality of that so I bought Ross-Tech directly.
And they've built a few "funnies" into the TDI. Like remember when your brake fluid was low on the original diesel rabbits and the glowplug light would come on? This may be like that.
(FYI - a "dongle" is a piece of hardware configured to work against integral software - software doesn't work without the correct hardware.)
Edit afterwards: Try Auto Zone. They offer "free diagnosis of check engine light issues." They might be able to give you your answer for free.
Last edited by Joe in NH; 09-19-2010 at 01:14 PM.
You can pick up a generic cable from China for less than $20 and use the shareware version from Ross-Tech. The knock off cables have a pretty terrible latency and you're on your own for support. That said, it's a very cheap and effective way to find and clear codes. I'm pretty sure Ross-Tech makes it easy to demo their software in this way on purpose. It only takes a few uses for you to *want* to upgrade to the full version. Go pick up a cheap cable from eBay and give it a shot. I think you'll agree after using it that it's incredibly useful software. If you like the product, please support them, without our support this wonderful tool wouldn't exist.
2006 Jetta TDI - Bone stock...for now
1977 Toyota Landcruiser - Custom body, lifted, 35" tires, Full Cage
1970 Triumph Spitfire