Dashboard warning lights: what they mean and what to do
Symbols vary by make, so check your owner's manual for the exact icon. The color tells you how urgent it is: red means stop or act now, amber means get it checked soon.
Check engine light (steady)
Amber
The engine computer has stored a fault code. The car is usually safe to drive for now.
What to do: Have the code read soon. Many parts stores will scan it for free, or use any OBD2 scanner. Then look the code up here.
Check engine light (flashing)
Amber, flashing
A severe misfire is happening right now. Unburned fuel is going into the exhaust and can overheat the catalytic converter.
What to do: Ease off, avoid hard acceleration, and get off the road when it is safe. Do not keep driving long distances.
Oil pressure light
Red
Oil pressure has dropped too low. Without oil pressure an engine can destroy itself in minutes.
What to do: Pull over safely and shut the engine off. Check the oil level. Do not drive until you know why.
Coolant temperature light
Red
The engine is overheating.
What to do: Pull over and shut the engine off. Let it cool before checking coolant. Never open a hot radiator cap.
Battery / charging light
Red
The charging system is not keeping the battery charged, often a failed alternator or broken belt.
What to do: Turn off accessories and drive straight to a shop or home. The car will run until the battery is drained.
Brake warning light
Red
The parking brake is on, brake fluid is low, or there is a brake system fault.
What to do: Check the parking brake. If it is off and the light stays on, check fluid and get the brakes inspected before driving.
ABS light
Amber
The anti-lock brake system has a fault. Normal brakes still work, but ABS may not.
What to do: Drive carefully and get it checked. Leave more room for stopping on slippery roads.
Airbag (SRS) light
Red or amber
The airbag system has a fault and airbags may not deploy in a crash.
What to do: Get it checked soon. Do not ignore it.
Tire pressure (TPMS) light
Amber
One or more tires is well below the recommended pressure. If it flashes and then stays on, the TPMS system itself has a fault.
What to do: Check all tires with a gauge and inflate to the pressure on the door sticker.
Traction / stability control light
Amber
Flashing means the system is working to stop wheel spin. Steady means it is off or has a fault.
What to do: If steady and you did not switch it off, get it checked.
Power steering / EPS light
Red or amber
There is a power steering fault. Steering may get heavy.
What to do: Drive carefully to a shop. Expect heavy steering at low speed.
Transmission temperature light
Red or amber
Transmission fluid is too hot, often from towing or a slipping transmission.
What to do: Pull over and let it idle in Park to cool. Reduce load before driving on.
Glow plug / wait-to-start light (diesel)
Amber
On a diesel, the glow plugs are warming up. Wait for it to go out before cranking. If it flashes or stays on while driving, there is a fault.
What to do: Wait for it to go out in cold weather. If it flashes, have the glow plug system checked.
DPF / exhaust filter light (diesel)
Amber
The diesel particulate filter is loading up with soot and needs to regenerate.
What to do: Drive at a steady highway speed for 20-30 minutes if it is safe to do so, or follow the owner's manual for a parked regen. See our DEF and DPF guide.
DEF / AdBlue light (diesel)
Amber
DEF is low, or the SCR system has a fault.
What to do: Top up with DEF. If the light stays on, have it scanned before a speed limit kicks in.
Water in fuel light (diesel)
Amber
The fuel filter has collected water.
What to do: Drain the water separator as soon as you can. Water damages diesel fuel pumps and injectors.
Low fuel light
Amber
The tank is getting low, usually with roughly 1 to 3 gallons left depending on the vehicle.
What to do: Fill up soon. Running out can damage some fuel pumps and on diesels lets air into the fuel system.
Reduced power / wrench light
Amber
Many vehicles (Ford's wrench light, GM's reduced engine power message) use this for throttle, pedal or powertrain faults that put the engine in limp mode.
What to do: Drive carefully to a safe place and have the codes read.
FAQ
What do the colors of warning lights mean?
Red usually means stop or act now. Amber or yellow means something needs attention soon. Green and blue lights just show that a feature is on.
Is it safe to drive with the check engine light on?
If it is steady and the car drives normally, usually yes for a short time. If it is flashing, slow down and get off the road when you can, because a severe misfire is happening.
Will a warning light reset itself?
Some do once the problem is fixed and the self-test runs again. The check engine light can take several drive cycles to go out.