When The Dreaded Warning Light Strikes
Your dashboard warning lights are designed to inform you of car maintenance issues that need your attention. Some, such as low wiper fluid, are helpful reminders. Others, such as brake, oil or temperature warning lights, require immediate attention in order to protect your car and your own safety.
Check Engine Light
Usually there is no need to be overly alarmed at this dreaded warning light. It is triggered by your car's computer when it detects a problem, typically in the emissions system. This warning rarely leads to extensive repairs or overhauls, and unless an immediate problem is evident in your car — such as rough or sluggish engine performance, or other warning lights — you can continue to drive.
Refer to your owner's manual for more information as to actions you should take, but usually the check engine light requires a service appointment with a mechanic as soon as possible. To diagnose the problem, your car needs to be checked with a scan tool. Typical problems include a loose or malfunctioning gas cap, moisture on wiring or electrical components, aging spark plugs and wires, dirty or clogged fuel injectors, a failed engine sensor, throttle position sensor or manifold absolute pressure sensor, or some other problem in the emissions control system.
Note: If this light is on, make sure you have your car serviced before taking it in for the state emissions control test. Otherwise your car will fail the test.
This is also referred to as a "malfunction indicator lamp" or "MIL," and it may say "Service Engine Soon" or something similar to that.
Temperature Warning Light
The "Temp" light requires immediate action. It means the car is overheating, or may be close to overheating. Driving in this condition can quickly damage the engine and may lead to permanent engine failure. Find a safe location to pull off the road, turn off your engine, and allow the car to cool. Once you've stopped, you may also notice steam from the radiator or from hoses. Never attempt to remove the radiator cap if the radiator is hot or very warm to the touch - this may cause the explosive release of steam and hot fluid that can scald you!
If the problem is simply very hot weather, you may be able to safely drive your car again after it has cooled; do so with the air conditioning turned off in order to avoid overloading your engine in the hot weather. If you've lost radiator fluid through a leak, or if you can't determine why your car overheated, it requires immediate service in order to avoid catastrophic damage to the engine.
Brake Warning Light
Most often, this light is on because your handbrake has not been released yet. Simply release the handbrake before driving.
But if it comes on at any other time, this can indicate minor to serious problems. Your brake fluid may be low, or your brake system may need repairs. Sometimes low brake fluid is a result of worn brake pads. Refer to your owner's manual for information on maintaining your brake fluid levels, or schedule an appointment with your mechanic — especially if the light remains on, or if you notice "mushy" brakes, brake noise, or stopping problems. A car with brake problems is potentially life-threatening.
Antilock Brake System Warning Light
On cars with antilock brakes, the ABS light indicates a fault in the antilock brake system. Typically this means that while the brakes may function, they will not have this advanced safety system until the problem is fixed. (If the regular brake warning light is also on, the problem is more serious and potentially life-threatening.) Your car should be checked by a mechanic as soon as possible.
Low Oil Warning Light
This requires immediate attention. Safely pull over, or find the nearest gas station so you can check the oil. Driving a car with low oil can cause severe engine damage, and if the oil runs down, your engine may seize.
If the light remains on after filling to the proper level, your car needs to be serviced by a mechanic. Never overfill the oil, even if the light is on, as this can also cause engine damage. Never add oil unless you've checked the oil dip stick and it reads "low" or "add oil."
Airbag Warning Light
This light indicates a malfunction in your airbag. It may simply indicate a sensor problem, or it may mean that your airbag won't deploy during an accident — or that it may deploy at any time. This is a potentially life-threatening problem. Your car needs to be checked by a mechanic as soon as possible.
Charging System Warning Light
This light indicates that the electrical system is not charging properly, possibly due to battery problems, alternator problems, or an issue in the electrical system's "brain." The light may suddenly come on if your alternator belt is loose or broken. If it is simply due to battery terminals/connectors are loose or corroded, many people can take care of this problem themselves by carefully cleaning the terminals and making sure the connectors are properly secured. Otherwise, the car should be checked by a mechanic.
Low Wiper Fluid Warning Light
This one is easy: it's time to fill your wiper fluid. During winter, make sure wiper fluid is resistant to freezing.