How many miles are on your xB?
If you're getting VSC and TCS problems, who knows what else could be wrong. The computer could be bad on your car.
If you want to fix the CEL, that is a possible solution.
Like I said earlier, I do not claim to know all when it comes to the 1nz-fe motor, or how it works, just what I have read on other forums, and what people have told me. I am also not a mechanic, just because I haven't had any issues doesn't mean I won't later on. I am only trying to be as helpful as I can to you, to help solve some problems.
You can always try disconnecting the battery and letting it sit for awhile, and then reconnecting it. I hear that lets the computer 'refresh' itself or something.