Automobile Warning Lights 101

Don’t Ignore Your Car’s Warning System. What you should know…

original auto warning system

Motometer, An Original Automobile Warning System.

When used properly, warning lights can prevent major failures and more importantly, save you from getting stranded.  Warning systems have been around since the early days of automobiles and have evolved to lighting up your dashboard with dozens of lights, symbols, acronyms and even vibrating seats in today’s advanced collision warning systems.

To get a complete understanding of your warning system always check the owner’s manual.  Even auto repair technicians will look in the glove box and consult your owner’s manual if they’re not familiar with a particular warning light in your system.  Every car is different and warning lights change all the time.  Air bag warning lights can vary from a simple spelled out word like “Air Bag” to an obscure picture of an exploding balloon.  In both cases, these are important alerts of an air bag system malfunction.

Each vehicle has its own acronyms. Cadillac has a “CCR” warning for their Computer Controlled Ride system, not a Credence Clearwater Revival alert like most old timers think. Toyota has a VSC warning for their Vehicle Stability Control.  Once again, the owner’s manual will have more information regarding your specific system.  We always advise our customers to keep the owner’s manual in their glove box for this specific reason.

As you can see, warning lights can get rather confusing so most people ignore them all together, even when they show up their dashboards. Don’t be that person! Bring your car to a certified mechanic to protect yourself. They’re there for a reason!

dashboard warning lights nissan

When a warning light turns on, don’t panic. Here are some tips to determine when you should call your mechanic:

1)      Individual warning lights on the instrument cluster are typically a higher priority and should be addressed if illuminated with engine running.

2)      Warnings that pop up on a digital display only (like “Service CCR”) are typically lower priority.  Some warning lights may do both.

3)      Warning lights will typically all light up when KOEO—Key On, Engine Off.  The engineers refer to this as a bulb check.  This step is especially important for emission testing and most tests require that the Check Engine Light circuit is capable of turning on.

I’ve run into many cars that had the bulbs removed so the light didn’t light. No light, no problem, right???  Wrong. All vital warning lights should illuminate when in the KOEO position. If they don’t, something is wrong.

This is a good check when buying a car.  Although not all cars have certain system, most have the top 3 we see the most for diagnostics; ABS (Antilock Brakes), SES (Service Engine Soon or Check Engine Light, may have picture of an engine), and Air Bag (usually a picture of a bag exploding in face).  If one of these doesn’t light upon KOEO then it either doesn’t have the safety system, or there is something wrong.

4)      Look at color.  General rule of thumb:  If it’s red, possible serious problem.  If it’s amber or orange, you generally can keep driving until you have it checked out.  Red oil can picture is serious……usually loss of oil pressure.  Engine will quit running and be damaged.  Orange oil picture usually means level is a little low.  You need to add oil.  Maybe a quart or two. Let me stress one warning light right now.  The picture of a red battery.  No, that does not mean you need a battery.  Plenty of my clients think that.  It means there is an issue with the charging system.  It is red because that is serious.  If the charging system quits, the vehicle is running off the battery and isn’t producing any of its own electricity.  It will eventually quit running.

5)      Today’s vehicle are so interconnected that one problem in one system will instantly cause a problem in another system.  This can lead to multiple lights at one time.  Only a qualified technician can determine that through diagnosis.  It’s very common for a check engine light to illuminate when a transmission problem has been detected.

The most important point to get across is to keep the owner’s manual in the glove box for easy reference should the need arise.

More information on specific warning lights;


Brake Light Warnings

tire pressure warning light

Tire Pressure Monitoring System


dashboard warning lights