Help Trouble Codes 26 27 28 ????????

I have a 1993 Grand am Se with a 3.3L im getting the codes 26,27,28
26-quad driver
27-28-3rd gear switch something with voltage ????
Dont know what to do ???????????????

Those 3 codes come up if the plug that connects to the transaxle is unplugged. I unplugged mine 2 years ago when I started having the dreaded torque converter lockup problem....now those 3 codes are always present on my '93.