That sounds about right. Only problem is you don't really know which one(s) is failing. When did you get your brake pads chagned last? Did you replace the senors at the same time? If so I would check the relay, if not get four sensors and go ahead and change them all, unless you have a way to get all four wheels up off the ground. In which case just change them out until you figure out which one(s) is out. Even if only one is out, these things are cheap and good to have around because most of the ABS lights are from brake sensors. If this doesn't work try the relay. I don't have any diagrams to show you how to do it, but www.pelicanparts.com
will most likely have a DIY or a parts diagram that would show you where the sensor is. From there grab a jackstand and your wrenches and find it.