1990 Oldsmobile Delta 88 Engine Code 26

Engine Performance problem
1990 Oldsmobile Delta 88 6 cyl Front Wheel Drive Automatic

At around 2200 rpm my engine has very poor acceleration, the transmission shifts down, but almost reluctantly and hard, there is also a high pitch humming noise which is very loud. If trying to accelerate quickly from say 15 mph the trans. Will shift very hard and the engine will display little power and the same humming noise will be heard. I also get an intermitten check engine light. I plugged in my Code Reader to see if it would shed any light on the problem, it showed a code 26 which is a Quad-Driver module or a Quad-Driver No. 1 error. I must admitt I have no idea what that is or if it is related to my problem. I hope someone can share some info with me on this problem!