To check duty cycle, you need something that can measure time; a multimeter generally cannot do this. If you have an oscilloscope you can find out the duty cycle by measuring the time between open/closed. Best way is VAG-COM since you can get readings direct from the ECU, but maybe somebody can chime in with another alternative (I can't think of any).
2001.5 A4 1.8TQM: FrankenTurbo, Motoza E85/91, EV14 750cc, 3" MAF, 3bar MAP, 034 HFC, custom 2.5" exhaust, TR18T FMIC, DW200 pump, I.E. con rods, Eibach Pro-Street coilovers, 034 RSB, A8/TT front & S4 rear brakes, SS brake lines, JHM SS/linkage, ECS RA4 + B7 RS4 clutch, 4:1 center diff, 034 street mounts, E-fan, catch can, Apikol diff mount & Stern diff bushings, Nexus 7 HU, custom sound system, bixenon, sport cloths.
2004 A4 1.8TQM USP: APR Stage 3+, S4 mirrors, RNSE
Past: 1998.5 A4 1.8TM