My understanding is that every Prius has a factory alarm which is only activated by the dealer using the Techstream software. It is a basic alarm with just using the door switches to sound if a door is opened, not sure if it has a glass break sensor. Then most every dealer in the US will activate it and add their own alarm box with a shock sensor on it, then sell it is an alarm system for $700 on the sticker of the car. It is really to give dealers more keyless entry control while it is on the lot, but it is sold to you as a feature. One good thing about it is the dealer add-on box allows you to add other sensors, my add-on box was the AL-101 Omega Ultimate. You might need to activate your factory alarm.
Going through this now myself. The instructions clearly say the orange wire needs to be grounded to the chassis to arm the sensor. It says that you can use an ig-on wire which in most vehicles grounds to chassis when the ignition is off but not the gen 2 Prii case. The ig-on in the fuse bus and j1 wire (referenced in one of the youtube vidoes) is about 300 to 500 ohms when the car is off which is not grounded to the chassis. Perhaps the sensor's requirements aren't as strict as the documentation, but the way to really do this right is to use a relay to ground the orange wire when the ignition is turned off.
