Years ago, when I was a service advisor at a local shop here in central Ohio, a customer called in. They were on the side of the highway, waiting for a tow. Their SUV stalled. Okay, were there any symptoms before sputtering out? Yep: odd noises from the engine area, poor acceleration, a flashing “check engine light, and, oh…a weird dash light that looked like a genie lamp with a drop of water coming out of the spout.

Now, I abhor phone diagnostics. We all know that phrase about “assuming” things. This one was fairly obvious, though. The customer had run their car out of oil and drove the dang thing until it died. And die it did.

These days, our cars do a pretty good job of telling us when something’s wrong. In fact, there are a large variety of dash lights that serve exactly this purpose. There’s a dash light for about every system. What’s more, they’re even color-coded to help you understand the severity of the light.

A blue, green, or white dash light means something is “on”

Green or blue typically indicates some type of vehicle accessory is turned on. This includes various lights, like your turn signals or high beams. It can also mean “Eco mode” is engaged, for instance.

Amber means “service soon”

Amber lights are paired with several different systems. They let us know which system needs to be checked soon. This might include the engine controls, anti-lock brake system, traction control, or others. General maintenance reminder lights might also be amber. While this light doesn’t indicate an emergency, it could disable certain systems until the malfunction is addressed.

Red indicates a malfunction worthy of immediate attention

If you see a red dash light, your car is trying to tell you to stop driving the car and give immediate attention to the issue at hand. Examples of red dash lights include the oil light (that “genie lamp” is an oil can symbol), the battery symbol, the brake warning light, and the airbag malfunction light.

While red lights don’t always mean your car is mechanically undrivable, as with the seatbelt reminder light or the airbag light, this color dash light is trying to make you aware of a safety issue serious enough to avoid driving.

Sometimes the issue is indeed super serious. If the red oil lamp or coolant dash light comes on, stop driving immediately to avoid catastrophic damage.