I've looked up the current law on the Transport Canada website http://www.tc.gc.ca/eng/motorvehicle...afety-1158.htm
Looks like this system isn't required by law....unlike the States. Weird because we are usually in lock-step with them in matters like this. I figure it has a lot to do with the lawsuits resulting from the Ford Explorer/Firestone tire blowouts/rollovers from 15/20 years ago