Engine warning lights explained: what every dashboard light means

The color tells you most of what you need. Red means stop or deal with it now. Amber or yellow means something needs checking soon. Green or blue just means a system is on.

The engine warning light, the one shaped like an engine, is amber. It means the engine computer has logged a fault. If it flashes, pull over.

What the colors mean

Carmakers use the same basic traffic-light scheme. The AA puts it in one line each: red means take immediate action, amber means have a garage check it, green means everything is OK. Synchrony's guide adds blue to the green group, since both show a system that is working or switched on.

Toyota's owner pages say the same thing in its own words. Yellow marks "an item of importance," like low fuel, that isn't necessarily a warning. Red marks a condition that needs immediate attention, such as low oil pressure.

The symbols themselves are standardized. ISO 2575 sets the symbols for controls, indicators and tell-tales on cars, trucks and buses, and it also specifies their colors (ISO). In the US, federal standard FMVSS 101 sets the required telltales, and it fixes red for the brake system warning and red-for-hot, blue-for-cold on temperature controls (eCFR).

One normal thing that worries people: every light comes on for a second or two when you start the car. That's a bulb check. A light that stays on after the engine starts is the one to pay attention to (AA, Synchrony).

The common lights by color, and whether you can keep driving

Here's the short version. The detail for each one follows below.

Light	Color	What it means	Can you keep driving
Oil pressure (oil can)	Red	Engine has lost oil pressure	No. Stop and switch off
Engine coolant temperature (thermometer in liquid)	Red	Engine is overheating, often low coolant	No. Stop and let it cool
Battery or charging system	Red	Alternator isn't charging the battery	No, or only as far as a safe stop
Brake system (exclamation point in a circle, or "BRAKE")	Red	Parking brake on, low fluid or a brake fault	No, unless it's just the parking brake
Airbag (SRS)	Red or amber, varies by car	Fault in the airbag system	Yes, but get it checked soon
Engine warning or check engine (engine outline)	Amber	Engine computer has stored a fault	Yes if solid and running normally. No if flashing
ABS	Amber	Anti-lock system fault, normal brakes still work	Yes, with care. No if the red brake light is also on
Tire pressure (TPMS)	Amber	A tire is low or the sensor system has a fault	Only to the nearest air pump or shop
Stability control (ESC or ESP)	Amber	Flashing: system working. Solid: fault	Yes if flashing on a slippery road. Get it checked if solid
Diesel particulate filter	Amber	Filter is clogging, usually from short trips	Yes, a steady highway run often clears it
Glow plug (coil symbol)	Amber	Diesel glow plugs warming up	Wait until it goes out, then start
Low fuel	Amber	Fuel nearly empty	Yes, to the nearest gas station
High beam	Blue	High beams are on	Yes
Turn signals, cruise control	Green	System is on	Yes

Sources: AA, Synchrony, Toyota, Edmunds and Wikipedia's tell-tale entry. Exact colors and shapes vary by make, so check your owner's manual for anything not on this list.

Red engine lights on cars: stop now

A red light means a fault that can damage the engine or make the car unsafe. Find a safe place to stop.

Oil pressure

The oil can symbol means the engine has lost oil pressure (AA). Keep driving and the engine's moving parts run without lubrication. Pull over, shut the engine off and check the dipstick. Synchrony says to top up if it's low, and to see a mechanic if the light stays on or comes back.

Engine temperature

A red thermometer means the engine is overheating. The AA says the usual cause is low coolant. Stop, switch off and let it cool fully before you open anything. A hot cooling system is under pressure and can spray scalding coolant.

Battery or charging

This light means the battery isn't being charged while you drive. The AA lists wiring, the alternator, the drive belt or a flat battery as causes. The car runs on battery power until it's drained, and Synchrony warns it may then fail to start.

Brake system

First check the parking brake isn't on. If it's off and the light stays lit, the AA points to low fluid, a sensor fault or worn pads. If the pedal travels further than usual, don't drive. If the red brake light and the ABS light come on together, the AA says that can mean a major brake fault.

What does an engine warning light mean

The amber engine light means the engine control computer has detected a fault and stored a code. Edmunds says the cause can be anything from a loose gas cap to worn timing parts or a failing catalytic converter.

Solid and flashing mean different things. A solid light is "serious but not urgent," in Edmunds' words. Get the code read soon and drive normally if the car feels normal. A flashing light usually means a misfire, and Edmunds says to shut the car down and have it towed, because the misfire can overheat the emissions system.

Fixing it costs $554 on average, a record, according to CarMD data quoted by Edmunds. The top repair is a catalytic converter at about $1,511, followed by an oxygen sensor at about $287.

We go into the causes in more depth in our guide on driving with the check engine light on.

One light people mix up with it: the service or maintenance reminder. Edmunds notes that light comes on when scheduled maintenance is due. It isn't a fault, and it won't store a code.

Amber lights: get them checked soon

Amber means the car still works but something is off. Most let you finish the trip.

ABS. The AA says most cars are fine to drive with the ABS light on if there's no noise from the wheels. Your normal brakes still work, but the wheels can lock in a hard stop. Drive with extra space.

Tire pressure. A tire is low, often from a puncture or a slow leak (AA). Check all four tires with a gauge. If they're all fine, Synchrony says to have the TPMS sensors checked.

Stability control. A flashing ESC light on a wet or icy road means the system is working. If it stays on in normal conditions, the AA says not to rely on it and get it checked.

Airbag. An airbag light means one or more airbags may not deploy in a crash (Synchrony). The car still drives, but get it looked at quickly. Toyota tells owners to see a dealer immediately if the airbag or ABS lights don't light up at all on startup.

Diesel lights. A DPF light usually clears after about 10 minutes of steady driving above 40 mph, by the AA's figure. If it stays on, a shop needs to look at it. The glow plug light just means wait before you start.

Green and blue lights

These are information, not warnings. High beam is blue. Turn signals, cruise control and similar status lights are usually green. Nothing to fix.

For more fault guides, see our symptoms section, and our repair costs section for what each fix runs.

What to do today

Note the color. Red: find a safe place, stop and switch off. Amber: finish your trip and book a check. Green or blue: nothing to do.
If the engine light is flashing, or it comes on with the oil or temperature light, stop and call a tow.
For a solid engine light, tighten the gas cap and get the code read for free at a parts store like AutoZone or O'Reilly.
For the tire light, check all four tires with a gauge and inflate to the pressure on the driver's door sticker.
Look up any light not covered here in the warning-light section of your owner's manual.

Sources

Featured image: Warning lights on a vehicle's dashboard glow brightly, indicating possible engine problems. The display shows the time as 1806 on September 4, 2020, creating urgency by Shixart1985, CC BY 2.0. Source