By the Dashboard Light: Understanding Your Car’s Gauges and Language


If you’ve ever wondered what on earth a pilot could need to do when flying an aircraft that could require use of the dozens of gauges and screens on the average cockpit, you’ve clearly not pay been paying attention to the display in your own car. There are at least 60 different ISO-standardized warning lights in use today, and many more proprietary ones that individual manufacturers use.

While the average driving test does measure the ability to read all kinds of road signs, they don’t ask you if you know what the warning lights in your own car mean; these can be extremely unintuitive in their design, after all. If you are not the technical kind and do not know the shape (sometimes cross-sectional) of the various internal components of your car, you wouldn’t know what they meant to look at them.

To get you started, here is an introduction.

Headlamp-related warning lights

If you were to disassemble a large, round headlamp of the kind cars from the 70s had, and view it side-on, you’d see that the reflector was roughly dome-shaped, but placed in a horizontal orientation. This horizontal dome-shape is used on warning lights do with the headlamp’s use.

A simple, cream-colored headlamp icon with a few lines in front indicates regular headlamps with dipped beams. A blue icon with straight lines indicates that the main beams or high beams are on (important, because it’s illegal in cities).

Malfunction warnings

The little yellow icon somewhere around the speedometer that indicates engine malfunction — the check engine light — is a well-known one. The design of the icon comes from the way an engine would look if viewed in profile. When you see it stay lit up or begin to flash, it’s time to visit the service centre. Many other malfunction indicators are less well-known, however.

A white icon showing your car in profile with a large wrench laid across tells you to get to a service centre for unspecified problems. One that looks like a cauldron with an exclamation point inside comes from what one of your tires would look like in cross-section. It indicates incorrect tire pressure. One of various icons that look like a key indicate anything from ignition switch malfunction to keyfob battery problems, or incorrect key insertion.

A cartoon car on a meandering road lines indicates that you have your stability control package turned off, and what looks like a little typewriter keyboard with a couple lines passing through shows that your diesel engine is putting out too much pollution. An icon that looks like a motorcycle shock absorber viewed in profile indicates a suspension-related problem.

An old-fashioned mechanic’s oil can with a drop at the tip indicates engine oil overheating, and a couple of wavy lines with a thermometer on top indicates that your engine coolant is too hot.

It can take time to familiarize yourself with these warning lights, but it would be a good idea to get to work on it. When you see a malfunction indicator come on, it’s important to find a trustworthy mechanic (go on for a deep search with pricing quotes), and get to work correcting the problem.

It’s important to take your car’s warning lights seriously. It might help you prevent major engine meltdown down the line.

Lewis Harrison works as an automotive repair technician. He likes helping people, and loves all things cars, so has turned his hand to article writing in his spare time.