There are 2 owner-reported brakes complaints for the 2020 GMC Yukonin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
I had an incident in my 2020 GMC Yukon, where the forward collision crash alert went off and there was total loss of brakes. The brake pedal went to the floor. After the crash alert ended, the brakes returned. This happened on the highway and could have turned into a disastrous event. The dealership has been unable to diagnose or recreate this issue. They claim they did not find anything and the vehicle is safe to drive. I have turned off the collision detection system in the meantime. I feel strongly that this is a software issue that needs addressed. GM has replied that they support the dealership but if I want a second opinion I can go to another dealership for input.
Ambient temp was 100 degrees for reference. Had been driving about 5 hours. Went to stop and had no power assist for brakes. This continued for at least 20 miles. Stopped and confirmed vac hose was connected. I tried to remove vac hose to check for vac at booster but was afraid I might break the part. Electrical plug at vac hose booster connection was secure. Continued driving and it began to work again. Condition: brake pedal took considerable foot pressure to apply brakes. Zero power brake assist was available. My qualifications; a past ASE master teck.
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 25, 2026