Today’s cars provide drivers with more information than ever before—about everything from tire and oil pressure to transmission and engine problems. The modern dashboard has become a communication interface between you and your car, so knowing what your car is trying to tell you can mean the difference between a quick fix and a costly repair. 

Let’s look at some common dashboard warning lights and what they mean.

Oil Pressure

Your car’s engine requires oil to lubricate its many moving parts, reducing friction and helping to ensure that your car runs smoothly. When your oil pressure is low, a warning light depicting a small oilcan will come on. You or your mechanic should check the oil levels as soon as possible and add sufficient motor oil to maintain recommended levels.  If you don’t know what weight of motor oil is recommended for your vehicle, check your owner’s manual or ask your mechanic.

Brake System

Your brakes are among the most heavily used safety features your car provides. Pads and shoes wear down with continued use and should be replaced regularly to ensure proper functioning.  Your car’s brake system also requires brake fluid to function effectively. A brake system warning light (an exclamation mark in a circle, bracketed by parentheses) signals a problem with your braking system. All brake problems should be addressed promptly by your mechanic to ensure safe operation of the vehicle.

Temperature (Engine)

All engines generate heat, but excessive engine heat can reduce engine and damage essential components, and radiator boil-overs can result in significant repair costs. Most car and truck engines operate optimally between 195 and 220 ºF. Your engine temperature warning light (which looks like a thermometer standing in waves) will come on if your engine temp exceeds recommended levels. Your car’s coolant levels and radiator system should be checked immediately to avoid serious and costly damage.

Temperature (Transmission)

Some cars provide a warming light to indicate when your vehicle’s transmission is running hot. Ideally, your transmission fluid should be between 175 and 225 ºF.  Increases in transmission temp can dramatically reduce the lifespan of your transmission. To avoid costly repairs, have your transmission fluid levels checked regularly as part of your vehicle’s oil change, and report any transmission issues to your mechanic or transmission specialist as soon as possible.

Check Engine

The check engine light (usually a silhouette of an engine block) can indicate a wide number of problems—from minor to major. Your mechanic has a code scanner that can diagnose the problem quickly. Engine problems don’t get better on their own, so if your engine light comes on, check with your service pro as soon as possible.

Battery Charge

Your battery not only helps your car start in the morning, it maintains power for your car’s essential electrical systems. Age and severe cold can reduce your battery’s ability to hold a sufficient charge. A battery light (a battery with + and – symbols) indicates a problem in charging capacity. Replacing the battery is easy; however, persistent electrical problems can have other causes (like a failing alternator). So if your battery light comes on even after installing a new battery, see your mechanic.

Tire Pressure

Many of today’s vehicles have a dashboard tire pressure warning. The light usually looks like an exclamation mark inside a bulging tire with treads below. Some cars will show a schematic to tell you which tire is low. Re-inflating the tire to the recommended pressure (usually 30 to 35 psi) should cause the sensor to switch off the light. Persistent low tire pressure warnings can indicate a slow leak, possibly cause by road debris that has punctured the tire, and the affected tire may need to be patched or replaced.

We hope these tips help reduce confusion about your vehicle’s warning light systems, and help you manage small problems before they become big ones.

About Main Line Transmission: Since 1987, Main Line Transmissions has given drivers in the Wayne, Devon, Berwyn, Paoli, Malvern, Exton West Chester and surrounding areas the best transmission service available. Working only on transmissions of every make or model, our technicians are experts through certification, continual training and years of experience.