My ESP/BAS light started coming on when I accelerated. The dealer diagnosed a failed internal steering angle sensor, part no. 5101115AA. Since your dealer has narrowed the problem down to a specific part, I would say that the diagnosis is correct and you need a new ABS module.

A link to the maintenance manual for the Crossfire was posted on this forum a number of months ago. Hopefully someone can provide a current link for you. If not, I'll go through the downloaded copy I have to see what needs to be done (the manual is rumored to be 3,000 plus pages so this could take some time).

I agree with bobs that the ESP/BAS system would not cause your car to die. I also had an incident when my car died on me. Problem turned out to be a loose lead to the battery (didn't find out which one though) so you may want to check to make sure both pos and neg leads are securely attached to your battery.

Brent