GMC Terrain Warning Lights: What They Mean

Red: stop or act now

Airbag Readiness Light

If it stays on after start or comes on while driving, the airbag system may not work; airbags might not inflate in a crash.
What to do: Have the vehicle serviced right away. PDF page 92

Amber: check soon

Pedestrian Ahead Indicator

A pedestrian is detected in front of the vehicle. PDF page 97

Other warnings and indicators

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 too, regular brakes are affected.
What to do: See your dealer for service. PDF page 95

Electric Parking Brake Light

Comes on when the parking brake is applied. Flashing after release or while driving means a parking brake system problem.
What to do: If the light does not display or keeps flashing, see your dealer. PDF page 95

Service Electric Parking Brake Light

Staying on or appearing while driving means a problem with the Electric Parking Brake; other safety functions may be affected.
What to do: Take the vehicle to a dealer as soon as possible. PDF page 95

Low tire pressure warning light

One or more tires are significantly under-inflated. It flashes about a minute then stays on if 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 251

Automatic Emergency Braking (AEB) Disabled Light

Automatic Emergency Braking or Front Pedestrian Braking is turned off, or unavailable due to malfunction, weather, or a dirty windshield. PDF page 97

Traction Off Light

The Traction Control System has been turned off. Wheel slip does not limit acceleration unless needed to protect the driveline.
What to do: Adjust your driving accordingly. PDF page 97

Green: system on

Vehicle Ahead Indicator

Green when a vehicle is detected ahead; amber if you are following a vehicle too closely. PDF page 97

Summarized in our own words from the 2026 GMC Terrain 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.