So I am pretty sure that B+M shift plus for the automatic transmissions some of us have is just a resistor(s) to reduce the amount of current to the Pressure Control Solenoid to increase line pressure, but what are the 2 resistances of it?? I would just rather make my own and not spend money on something I can make myself. And anyone correct me if I'm wrong on this please.

 

It's only $40. You wanna risk ruining your transmission so save $40 and buy a 50 cent resistor instead?

 

I am aware of the low cost of this product. I just like to tinker and play with my vehicles to better understand the concept, I guess.
And here's 2 scenarios.
A: large resistance + resistance within TCM= very low current to PC solenoid = much higher line pressure (still under max)= extremely hard shifts and no damage
B: small resistance + resistance within TCM = slightly lower than stock current to PC solenoid= slightly higher than stock line pressure = slightly harder shifts and no damage.
I don't see where I would cause damage unless you could point it out to me? Thanks for the concern though.