I have a 2018 Canyon that developed what I’d call abnormal turbo noise in the cab when approaching 2000rpms and beyond. I chalked it up to colder more dense air when the temps dropped well below 0° However after 3 days of this I then was greeted to a check engine light on the dash. After doing some preliminary shake downs I believe it to be directly related to the exhaust brake because now the truck will not allow me to engage the tow/haul/exhaust brake feature. When pushing the button the dash light illuminates momentarily then goes off. I think my exhaust brake is partially engaged and building preboost and that would explain the excessive turbo whine due to the restriction. Not to mention a drop in fuel economy and “pick up”. No limp mode initiated either as a fail safe which I think is kinda weird. I have it scheduled for service in a couple days and will follow up with the dealership findings. Anyone here heard of this or familiar with similar issues? Otherwise I love my Canyon diesel. Thank guys.