A “Check Engine” light can be a headache for a car owner, but you shouldn’t ignore the problem it indicates. The Check Engine light — more formally known as the Malfunction Indicator Lamp (MIL) — is a signal from the car’s engine computer that something is not functioning properly. Check Engine lights come in orange, yellow or amber, depending on the manufacturer.

When your car’s “Check Engine” light comes on, it’s usually accompanied by a sinking feeling in the pit of your stomach. The light could mean a bigger problem, like a bad catalytic converter, or it could be something minor, like a loose gas cap. But in many cases, it means at minimum that you should be visiting the repair shop to locate the malfunction and get the light turned off.

So if the Check Engine light comes on and it’s steady rather than flashing, what do you do? The most obvious answer, of course, is to get the engine checked. But many people do nothing, perhaps fearing an expensive repair bill. Some drivers with older cars want to squeeze out as many remaining miles as possible without visiting a service garage. But before they can pass their state’s vehicle inspection, they have to get the light turned off. If the light is lit, there’s a good chance the car is releasing excess pollutants or consuming too much gas.

If the light comes on, you should first see if the gas cap is loose: That’s a common cause. A loose cap sends an error message to the car’s computer, reporting a leak in the vapor recovery system, which is one aspect of a car’s emissions system. If the gas cap is loose, tighten it and continue driving. Even so, it may take a short amount of time for the light to go off. If the light remains lit, it’s important to promptly figure out and address the problem(s) indicated by the light. Ignoring them could lead to larger, more costly problems later.

So if the Check Engine light is flashing, what do you do? If the light begins flashing, it indicates a more serious problem, such as a misfire that can quickly overheat the catalytic converter. These emissions devices operate at high temperatures to cut emissions, but can pose a fire hazard if faulty. Pull over immediately and shut the vehicle off. Call your AAA or nearest towing service to have the vehicle towed to your automotive repair facility.


The service vehicle soon warning light is a vehicle monitoring system that tracks all of the chassis control systems. The light comes on when there is a fault condition in an area of the vehicle chassis systems such as the anti-lock (ABS) brake system, the traction control (TCS) system, the electronic suspension system, or the brake hydraulic system. This should not be confused with the Service Engine Soon (SES) Light equipped on some vehicles. It’s a good idea to read your vehicle owner’s manual and familiarize yourself with your vehicle’s warning lights to prevent any confusion.

 TIRE PRESSURE Warning Light:

The tire pressure warning light is a little yellow icon that looks like a cut-away view of a tire with an exclamation point in the middle. If a tire’s pressure falls below 25 percent of the pressure specified by the vehicle manufacturer, the tire warning light will illuminate. Some systems will illuminate the tire warning light if the tire pressure is too high. It is important to read the portion of your vehicle owners manual that covers the tire pressure monitoring system. That way, if or when the tire warning light comes on, you’ll know exactly what to do.

 BRAKE Warning Light:

When the brake fluid falls below a specified level, the BRAKE warning light will illuminate (in some cases, a message is displayed on the dashboard). The warning indicator will come on while the brake system still has enough fluid to properly function. If the light is intermittent and seems to come on and off depending on whether the vehicle is turning, it may mean that the brake fluid level is getting low. If the BRAKE warning light comes on and stays on, this indicates that there is a persistent problematic issue with the brake hydraulic system. The warning light can come on when a change in system hydraulic pressure is detected.

 ABS Warning Light:

The ABS warning light—anti-lock/anti-skid brake warning system—will come on when there is some type of fault condition with either the ABS brake system or the normal service brake system. It can also come on if the brake fluid level is low in either the master cylinder reservoir and/or the ABS brake system reservoir (if equipped).

 CHARGING SYSTEM Warning Light/BATTERY Warning Light:

The charging system/battery warning light is one of the most critical warning lights on any vehicle. Whenever this light goes on, it means that the vehicle is running solely on battery power and will only be able to drive a very limited distance before it runs out of electrical power and dies. If this light comes on while you are driving, find a safe place to pull over and have your vehicle towed to a repair shop.


The traction control system uses a computer to detect whether one (or more) of the wheels has begun to slip and lose traction with the roadway. The warning light usually comes on when the system detects a loss of traction, like in snowy or rainy weather, and the system is intervening to maintain traction. It’s a good idea to read the section in your vehicle owners manual to familiarize yourself with how your traction or stability system operates.

 AIR BAG Warning Light:

The supplemental restraint system (SRS) warning light is most commonly known as the AIR BAG light. This is a computer controlled system designed to deploy one or more driver, passenger, and side air bags. If the light stays on after initial startup, there is fault somewhere in the SRS system. The system is disabled at this point. In the case of a collision, the air bags will not deploy and the seat belts will not tighten, nor will any additional features activate. Take the vehicle to a qualified repair shop to be properly diagnosed and inspected.


If you see this light, it could mean two things. It could be that the oil level is too low or there is a problem with the oil level sensor system. It could also mean that the oil pressure is too low and a potentially catastrophic event is taking place. If the light comes on, check your oil level immediately. If the oil level is fine, the problem is the oil pressure. Don’t drive the vehicle—an engine with low oil pressure can be ruined in a matter of seconds.

 ENGINE TEMPERATURE Warning Light / Warning Sign:

When the temperature light comes on, AND/OR, if the needle on the temperature gauge rises higher than 2/3 of the entire range, your engine is overheating. Immediately turn off the A/C and any other nonessential systems that are running, including the radio. When safe to do so, pull over. DO NOT open the hood for at least 20 to 30 minutes. While waiting, call a tow truck and have the vehicle towed to a qualified repair shop for a complete cooling system inspection and diagnosis.

  Oil Change Indicator Light: 

To let drivers know when to change out their engine oil and filter, many modern vehicles have oil change indicator lights. If this light or message appears, you should have your oil changed within one to two weeks.