2017 KW t680 isx15 cm2350 460k miles
Sitting idling with the tractor brakes set and out of nowhere the speedometer shoots up to 10-15 mph then back down. Error warning pops up on the dash that says "Warning: air brakes in engage while driving" or something along those lines and the transmission says there is a fault. It kicks me onto drive line and ruins a reset when it happens. Any ideas what it might be?