viper 5901 upgraded sensor needed?

So I've finished my install of a Viper 5901 unit. I've cranked the sensitivity both ways by using the remote up to 15 and tried 1 and the unit doesn't go off even when physically impacting the unit. All the doors are closed and alarm enabled. Fwiw my glass impact sensor does work. So what are your thoughts is it just a bad sensor or are there some tricks or things to check in your experience? Maybe I just need to get an external module. Thanks.

I was told to include make and model so... Viper 5901 Mazdaspeed3 2008 Sport (no stock alarm)

if your physically impacting the unit and it still not going off then it is either in VALET mode or a faulty unit. More likely a faulty unit if the other sensor is still activating as it also should not if in valet mode.Gary Sather