92 240sx auto. solenoid a and b codes

[1hotsilvia]

How do solenoid a and b work? My car loses drive and overdrive (I believe it's going into safe mode) only after I lay into the throttle. It screws up if I hit around 4000 rpm regardless of what gear (even neutral). If I drive normal my car throws no tcm codes, if I cause my car to act up by laying into the throttle I pull a code 4 and 5. (solenoid a and b) any ideas?