Ford Mustang Warning Lights: What They Mean

Amber: check soon

Malfunction Indicator Lamp

Steady: emission control system malfunction detected. Flashing: engine misfire may be occurring, which could damage the catalytic converter.
What to do: Avoid heavy acceleration and deceleration, and have the vehicle checked as soon as possible. PDF page 155

Other warnings and indicators

Oil Pressure Warning Lamp

If it stays on while the engine runs, there is a malfunction. It also illuminates briefly when the ignition is switched on.
What to do: Stop the vehicle, switch the engine off and check the oil level. If the level is fine, have the vehicle checked soon. PDF page 155

Powertrain Warning Lamp

A powertrain or four-wheel drive fault exists when it is on while the engine runs.
What to do: If it flashes while driving, slow down immediately, avoid heavy acceleration and deceleration, and have the vehicle checked soon. PDF page 155

Passenger Airbag Status Indicator

The off lamp shows the front passenger airbag is disabled; the on lamp shows it is enabled.
What to do: If an adult is seated and the off lamp is lit, have them sit upright for two minutes or ride in the rear. PDF page 68

Auto Hold Active Indicator

Auto hold is active and holding the vehicle at a standstill. PDF page 210

Summarized in our own words from the 2026 Ford Mustang 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.