I have the same problem...
It started in February 2007 and was intermittent -- the light going on and off. Eventually, it started staying on all the time. I suspect that this particular component is a weak link in the VX design. A lot of owners have complained about it.
Did you know that Isuzu issued a recall for the ABS module in one of the Amigos -- 1998, I think? They did. But they didn't issue a recall for the VX. In any case, I've been driving safely without ABS for 6 months, but I intend to get it fixed with junkyard parts soon.
I would caution those who take the attitude that "cars drove fine without ABS for decades and therefore this isn't a problem to worry about" with the following: Driving without ABS can expose you to a lawsuit if your vehicle causes an accident. The plaintiff may assert that you failed to properly maintain your vehicle's factory safety systems, and they could sue you for damages. We live in an era where this safety system is standard on new vehicles. A responsible owner should always maintain every safety system on their vehicle.
Grant
2000 Proton Yellow #756
"THE UFO"
Seattle, Washington