Volvo applying brakes itself

You may have an evil spirit in your truck. You need to see an exorcist asap. Meanwhile keep garlic in slipper and throw salt on floor.

 

How about the brake pedal spring that holds it up off of the switch?

 

Water/corrosion in the Diagnostic port? Or other place in the J1939 data link.

 

LOL, I don't have a clue what is going on with yours, but if it is kicking it off of cruise, I am betting some signal is going through the computer to do it.

Back before electronic days, I had a customer that had a truck, that would turn it's head lights on randomlly, usually when parked at night. He said it was possessed. lol
Any way, I decided it was the dimmer switch on the column, and he left it for me to repair. When I closed up that night, the lights were on, so I disconnected all the grounds on the batteries. I was called out in the middle of the night for a wecker or service call and when I got to the shop, the lights were on again. Now I was beginning to think he just may be right. lol
the wind was howling that night, and it must have rocked that cabover enough to get one og the ground cables to move back far enough to touch the battery terminal. lol

 

Does it have any sort of collision avoidance system, if so I'd start there.