WARNING: This page is about a different car, the 2006 Audi A4, 2005 Audi A4, 2004 Audi A4, 2003 Audi A4, and 2002 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.
Connect multimeter for voltage measurement as follows:
Fig 1: IIdentifying Camshaft Position Sensor Harness Connector Terminals
Courtesy of AUDI OF AMERICA, INC.
CAMSHAFT POSITION (CMP) SENSOR: TERMINAL 2 MEASURE