94 olds 98 problem azzkicker

I still have my olds 1994 - 98 parked because it keeps cutting out and then it will restart right away. I took it in to a respectable mechanic and he read the codes. it has the old obd computer he tells me and pulls some codes. The one that he thinks may be doing this is code P1629 PASSKEY FUEL ENABLE CIRCUIT. We cleaned the key and tried another key. We cleaned the ignition switch(around the ignition), WD 40 and blew it out with air. it still dies on me very speratic. sometimes if at idle and sometimes running down the road. it always starts back up. but I never can predict when it will accur. This one has us all baffled. can anyone tell me what this code is and what this PASSKEY FUEL ENABLE CIRCUIT is. I would be very greatfull for ANY info on this one. The car has 138,ooo on it and it runs great until it stalls in the middle of th street or going down the highway and always starts right back up.I may take the dash appart this weekend and the steering covers and look for a pinched wire or something.runaround please reply Mark in PA.