2002 GMC Sonoma 6 cyl Four Wheel Drive Automatic 191000 miles
My 2002 GMC sonoma, when driving at highway speeds will shift in and out of overdrive for no reason. It has done this for about 2 years now. There is no rhyhm or reason to when it will shift in and out. I could be traveling 65 or 70 mph on a flat surface and it will shift both in and out of overdrive. I could also be going down a hill, up a hill, etc. And it will shift both in and out of overdrive. I can be going downhill and the transmission will shift into passing gear without me giving it more gas. I have disconnected the battery thinking the computer had a bad code (misfiring, etc.) That could have caused it. I have also had the overdrive solenoid replaced and it still does it. My next thought it could be a speed sensor. Any ideas?