1994 Buick Park Avenue Vehicle Stalls and MIL LIght is on

Have a 94 buick park ave. The transmission was slipping so we had a new one put in. After picking it up, we notcied that it still makes a slam noise when shifting between gears on occasion, and the vehicle stalls out randomly. The MIL Light was on scince we got the car 3 years ago, never thought much of it. Took the car back to transmission shop and they test drove it and said the new transmission is fine and they got the scan tool out and said the code was the cam sensor and thats what could cause the stalling and running rough intermitantly. So I replaced the cam sensor, and touched negative and postive cables together to clear memory. Started it up and light came right back on and the light test feature on the roof that tells you if one of your lights are out, they were all flashing fast even though all the lights worked. What else could cause the cam sensor code if its not the cam sesnor?