Modern vehicles have more than 60 possible dashboard warning lights. Most drivers recognize only a handful of them — and when an unfamiliar symbol appears, the instinct is often to ignore it and hope it goes away.
Red warning lights — stop driving or act immediately
🔴 Oil pressure warning (oil can icon)
This is the most critical warning light on any vehicle. It means oil pressure has dropped to a dangerous level. Pull over and turn off the engine within seconds — not minutes. Check the oil level before restarting. Related codes: P0520, P0521, P0522.
🔴 Engine temperature warning
The engine has exceeded its maximum safe operating temperature. Pull over immediately and turn off the engine. Do not remove the radiator cap while hot. Related code: P0217.
🔴 Battery / charging warning
The charging system is not maintaining battery voltage. The vehicle will run on battery power alone — typically 20–45 minutes before electrical systems begin failing. Drive directly to a shop. Related codes: P0562, P0620.
🔴 Brake warning light
If the handbrake is not applied, a red brake warning light means low brake fluid level — potentially a brake fluid leak or severely worn brake pads. Have it inspected immediately.
🔴 Airbag / SRS warning
The supplemental restraint system has detected a fault. Airbags may not deploy in a crash. Related codes: B0001, B0002.
Amber/yellow warning lights — schedule service soon
🟡 Check engine light
Steady amber: a fault has been stored. Safe to drive but schedule a diagnostic soon. Flashing: active misfire — pull over immediately. See: What does the check engine light mean?
🟡 TPMS (tire pressure) warning
One or more tires are significantly underinflated, or a TPMS sensor has failed. Check tire pressure immediately. Related codes: C0750–C0765.
🟡 ABS warning light
The anti-lock braking system has detected a fault. Normal braking still works, but ABS will not activate during hard stops. Related codes: C0035, U0121.
🟡 Transmission temperature warning
Transmission fluid is overheating. Pull over and let the transmission cool. Continued driving causes rapid fluid degradation and potential transmission failure. Related code: P0218.
The one rule that applies to every warning light
Never ignore any warning light for more than a day or two without reading the associated code. Use the MyOBDCode dashboard light guide to look up any unfamiliar symbol on your vehicle.