Check engine light on (yellow) or blinking

The engine icon on the dash — what it means and whether you can keep driving.

Solid yellow — ECU detected a fault that doesn't require immediate shutdown. You can drive to the shop, but don't ignore it. Pull the codes first.

Blinking yellow — active misfire that destroys the catalyst. Reduce load (ease off the throttle), drive to the shop by the shortest route. Every 6 miles with a blinking CEL costs you the equivalent of a new catalytic converter ($500-1500).

Red (rare, depends on car) — critical fault (oil pressure, temp). Stop immediately.

First diagnostic steps

  1. Don't panic — pull the codes with a scanner
  2. Record or photograph the code + freeze frame
  3. With blinking CEL — no full throttle
  4. Do NOT clear the code until root cause is known
  5. Check oil and coolant levels before driving to the shop

Likely fault codes

Click a code for detailed description, causes, and diagnostic plan.