In the past twenty years hundreds of infants and young children have died after being left in vehicles, usually by accident. When turning the vehicle off, drivers of the Yukon XL are reminded to check the back seat if they opened the rear door before starting out. The GLS doesn’t offer a back seat reminder.
The Yukon XL (except SLE with front bench seat) has a standard front seat center airbag, which deploys between the driver and front passenger, protecting them from injuries caused by striking each other in serious side impacts. The GLS doesn’t offer front seat center airbags.
Over 200 people are killed each year when backed over by motor vehicles. The Yukon XL Denali offers optional Reverse Automatic Braking that uses rear sensors to monitor and automatically apply the brakes to prevent a rear collision. The GLS doesn’t offer backup collision prevention brakes.
The Yukon XL’s standard lane departure warning system alerts a temporarily inattentive driver when the vehicle begins to leave its lane and gently nudges the vehicle back towards its lane. A lane departure warning system costs extra on the GLS.
Both the Yukon XL and the GLS have standard driver and passenger frontal airbags, front side-impact airbags, side-impact head airbags, front seatbelt pretensioners, height adjustable front shoulder belts, plastic fuel tanks, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, rearview cameras, available all wheel drive, blind spot warning systems, around view monitors and rear cross-path warning.