Error Codes
G'day,
Best place to start for anything like this is a workshop manual, such as a Gregory's manual. For roughly $30 or so, you'll have more info on your car than you could ever need - including the error codes you're after.
Look in anywhere like Repco, Autopro, Super Cheap etc etc or any good automotive book store.
I do have the book for my VR, which has a complete listing of the codes and how to acces them and treat them. I would not necessarily think they'd work for your VT though... But if you want them, just let me know.
Chris.