GMC Yukon and Yukon XL Warning Lights: What They Mean

Red: stop or act now

Airbag Readiness Light

Shows an electrical problem in the airbag system. Airbags might not inflate in a crash, or could inflate without one.
What to do: Have the vehicle serviced right away. The light should come on briefly at startup; if it doesn't, have it fixed immediately. PDF page 117

Amber: check soon

Antilock Brake System (ABS) Warning Light

ABS has detected a problem. Regular brakes still work, but ABS is not functioning as expected. With the brake warning light, regular brakes are also affected.
What to do: See your dealer for service. PDF page 121

Four-Wheel-Drive Light

Shows the selected drive mode and flashes during a shift. If amber, the four-wheel-drive system may have a malfunction.
What to do: See your dealer if the light is amber. PDF page 121

Other warnings and indicators

Tire Pressure Warning Light

One or more tires are significantly under-inflated. If it flashes about a minute then stays on, the TPMS has a malfunction.
What to do: Stop as soon as possible and inflate tires to the pressure on the Tire and Loading Information label. PDF page 351

Passenger Airbag Status Indicator

ON means the front outboard passenger airbag may inflate; OFF means the sensing system turned it off.
What to do: If both stay lit, neither lights, or the airbag readiness light is on, there may be a problem. PDF page 117

Hill Descent Control Light

Displays when the system is ready for use; flashing means the system is active. PDF page 121

Green: system on

Adaptive Cruise Control Indicator

Lit white when Adaptive Cruise Control is on, and green when it is active. PDF page 229

Summarized in our own words from the 2026 GMC Yukon and Yukon XL owner's manual (AI-assisted; every light name was matched against its cited page 2026-10-18). Your vehicle may not have every light, and other years can differ. A red warning that stays on usually means stop safely and check: your manual has the final word.