Cruise control cutting out sometimes the petal is dead.

Hey everyone, got a question. I've gother a 2012 vnl 780 with the D13 and ishift with about 1.2 million km on the Truck 650,000 miles. Transmission is about a year and a half old. Truck is running well. But I've been having some electrical gremlins. Besides the odd low scr performance that threatens derate once and a while (every few months) but never does it eventally goes away ,but it wants a parked regeneration. Went out east a month ago ran through some really wet salty roads and my vss lost connection with the ecu. ( switched the J1939 connector for the pto with the one connector in the vss harness (don't know how but it worked) switched it back and it's been fine since.

But now I'm having cruise control issues. Also lazy shifts and in auto mode sometimes the gears 8 to 9 and 10 to 11 will even grind. When I use manual mode it does not. For the cruise control it will just stop working. The CC is still on and as far as the ruck thinks it still working. Only ways to get it to go is either hit brakes and really set it. Or depress the throttle a little bit and it carries on like nothing happened, back up to speed. Or just leave it once it drops 30kph it wakes up and regains speed on its own. I've also noticed sometimes at low speeds like turning at an intersection ( not sure if it happens between shifts) but the petal looses a lot of responce. Suddenly I have to give it 3/4 to accomplish what 1/4 should. I replaced the petal since the old pos smelt burnt in the connector. New one does seem to make the truck sgift a little smoother but the problems persist. Transmission internal ribbon harness and external harness have been replaced in the past 3 months. Only original harness is the forward chassis harness. Anyone have any ideas what may be wrong? Pablo? Lol

 

I'm leaning towards either the chasis harness or clutch actuator. Noticed recently when coasting at say 75mph in manual the rpm's should stay at the running rpm's. Mine will drop 400rpm like the clutch was applied. Also the Jake brake cuts in and out . Seems to be worse on rough roads.