AAN Compression Testing Info
 

To start, remove the spark plugs, as detailed in this Spark Plug Replacement post.

To disable fuel going into the cylinders during this exercise, pull No. 17 fuel pump fuse *AND* pull the injector connectors off OR remove the injector fuse in the brown S72/116 fuse holder above the ECU, as documented in this above ECU fuse call-out post

From a previous kinderutz post:

Compression pressures
New: 9-14 bar (131-203 psi)
Wear limit: 7.5 bar (109 psi)
Max. permissible pressure difference between all cylinders: 3 bar (44 psi)

Check page 42 of 93 in the pdf linked below:

http://12v.org/urs/AANCompressionTes...cedureInfo.jpg

More AAN engine info here (download and save): http://s2-audi.co.uk/workshop/aan/aan.pdf