For 2001 Avant, use the 2000 manual. For 2001 saloon, use a later manual if available.
The Haynes manual in question is intended to cover the B5 chassis only, and the only really unambiguous way to do this is to say that it covers models through 2000 only.
Because ... in late 2000, the new B6 chassis was introduced, but for the saloon only. The B6 chassis for the Avant was introduced during 2001. I know this because I was one of the lucky ones to get one of the very last B5 1,8 Avant TS, made in late October 2000.
It took about three years, until 2005 I believe, for Audi to start delivering the 190HP (equivalent to 1,8 TS) again.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.