Getting Code 46

I have a 1988 Corvette 60,000 miles and I keep getting the SES light to come on about every 5th crank or so...Sometime it stays on and will go off on the next crank...Scanned the computer and getting a code 46...I know this has something to do with the VATS system..Do you think it is the ignition switch, a short somewhere in the circuit, a worn key???..Where should I look first?