Replaced the solenoid and sensor with mopar parts....check engine light is gone and car shifts into gears very smoothly. However, i am still having the following problem that I did before-While cruising at highway speeds, the engine will randomly surge, rpms will jump up 2-300 for a second or two, then go back down. It almost looks like the TCC Lock-up is engaging and disengaging for absolutely no reason. This doesn't happen all the time and will just randomly show up a few times on highway drive.
It is the GC with 4.0L which as been plagued with various electronic gremlins over the years (last one was a year and a half ago-engine bucking and stalling-which eventually resulted in a new computer installed at dealership after a good couple months of head scratching).
Any ideas on why it is doing this surging thing? I dont know if its related but I also noticed that sometimes when I put the car into park or neutral after driving it the engine idles real high for no reason-like 1,300-1,500 rpms.