About Dashboard Warning Lights

If you own a car, you have probably noticed that check engine light or the oil light on your dashboard. These dashboard warning lights are not something to ignore. Each one tells you something is wrong with your car and that it is time to get a tune-up, oil change or other type of service.

Types

There are several different dashboard warning lights; the main one is the check engine light. This is shaped like an engine and is usually orange. It comes on when the sensors in your car detect a low fuel-oxygen mix or one of the many other issues that can arise in an engine. There are hundreds of sensors in your engine alone that can cause this light to go on. The others include the check oil light (shaped like an oil pan), the temperature warning light, which refers to the radiator, and your service light, which is sometimes shaped like a wrench.

Significance

When the check engine light goes on, it simply means your car's diagnostic computer has detected a problem in the engine. It could be something as simple as a leaking gasket or as serious as damaged piston. The check oil light tells you that you car is running low on oil. The temperature light will tell you that your car is running too hot, that you may be low on coolant, or that your radiator may be failing. The service light tells you another type of service is needed, like a simple engine tune-up or wheel balance issue.

Function

Each warning light is connected to a sensor. The check oil light reads the level of oil in your oil pan (which is why it comes on at startup. The temperature light responds to the temperature of your radiator fluid, which normally runs around 190 degrees F in most cars. Higher performance sports cars sometimes run hotter. When this temperature runs above 200 degrees F, the light comes on. It doesn't always mean a big problem is looming, however. Sometimes this light comes on on an old car after it has been running for several hours.

Benefits

On-board diagnostic computers, which tell these lights to come on, have many benefits for car owners. They can immediately tell when something is wrong and are designed to detect problems before they happen. This allows the car owner to avoid damaging the car by driving it unknowingly while things aren't working the way they should. Minor problems like a leaking gasket can be fixed before they turn into a major problem like a blown head gasket or seized engine. Small problems like a bad fuel-oxygen mix hinders car performance and mileage, and a check engine light will detect this problem so it can be fixed.

Misconceptions

Not all dashboard warning lights indicate serious problems, but they do indicate a problem. Many car owners ignore them, because they do not believe a mechanic will be honest and fix only what is wrong. However, those lights are connected to a diagnostic computer that spits out codes that indicate specific engine problems; a mechanic would be hard pressed to fool anyone who asks for one of these print outs. Since the car is diagnosed by the computer, it actually eliminates the human error factor that ends up costing car owners more.

Resources

• Info on the check engine light
• How to deal with a check engine light