Maybe confusing TCM under dash?(transmission Control Module) with Valve Body which is inside pan.What I would try is looking at wiring diagram (TCM to trans ckts & solenoids & connecors) Find and break connector at transmission with the pins to THAT solenoid you wanna check and "energize" it using a fused jumper (try first a new 9V battery) and listen carefully for the "click" inside pan,they're fairly loud , and yes ,clicking may not demonstrate 100% good - it's a start. If you get action , now trace up to the TCM ,do a continuity of that "in-between" run to trans conn. OK ? Then plug in/ unplug trans connector 3 times,for best connection.
NOW energize the disconnected TCM connector with wiring going all the way to that solenoid -listen for click ?? Now reconnect that TCM connector/disconnect "IN'n -Out" 3 times in a row for "best connection".
All plugged in ? Now rig for test start/ride ?
Still have a problem / code ??? Persists ?? Now ya gonna HAVE to prolly remove pan & Valve Body eh??