A: The voltage regulator is integrated into the computer of the fuel injection system, known as the Single Module Engine Controller (SMEC) or the Single Board Engine Controller (SBEC). Special diagnostic tools are required to check the regulator, which are only available at dealer service departments and some repair shops. If the regulator is found to be faulty, the computer must be replaced. Fortunately, computer replacement is covered by a Federally mandated extended warranty, which can be found in your owner's manual or by consulting your dealer for more information.