Forward Collision and Lane Change Warning not working

[Dave H]

I bought a 2020 Sierra 1500 Denali 5 days ago and can't seem to get the lane change/lane departure function to work. I also noticed my forward collision warning is not working. For the lane change I have the white icon on the info center and the two white lines in my HUD when I turn lane departure button on. When driving at a constant speed on a lined road i see the HUD constantly change between white and green lines but not red when i slowly swerve over the line. I know my other car's lane warning works on these roads. For the forward collision alert I noticed when  backing up and moving forward that I was not getting forward collision warnings. Rear beeps were loud and clear but nothing on the front until I was literally inches from an object. I set up a 3' X 5' piece of cardboard and drove down the driveway at about 15 MPH and had to apply brakes because there was no warning. As I inched up to the cardboard it sounded when I was less than a foot from hitting it. I have read the manual and gone over every setting I could find but nothing seems to help. I would just go to the dealer but I'm on vacation about 3 hours away so I thought I would reach out to the community and see if someone has a solution. 

[tmo]

For the forward collision it uses the camera and detects brake lights which is why it didn’t go off with the cardboard. This is why you can be following behind (tailgating) a car and it doesn’t brake, but when they press the brakes and the truck senses that it’s getting closer is when the it alerts you and will brake. Keep in mind that this might only work below 55 mph if it’s like my 2018. I’m pretty sure it’s worked at higher speeds for me, but the manual states 55 mph is the max.

[Dave H]

thanks tmo! I did not realize that. Maybe I need to dig into the manual a bit more. I have done some more research, watching a lot of YouTube and it appears the marketing material for the safety systems is better than the system. So I wonder if the pedestrian detection system works? Bottom line is I love the truck but a little dissatisfied with the safety technology.

[tmo]

Oh I didn’t realize that it had pedestrian safety systems. I’m actually going to look at a 2020 Denali this week sometime so I’ll do some research and post my findings.