Ask Joe Mechanic: Dashboard Indicator Lights (Part I)

This week, I want to cover the subject of dashboard indicator lights, more affectionately known as “idiot lights”. Many

people misunderstand what they mean, and by doing so, do serious damage to their

vehicle and cost themselves a lot of money.

I want to propose to you an analogy that I have gone by, and is a fairly realistic way to look at this subject. Compare your

dashboard lights to a traffic light. A green light, or no lights on means go. A yellow traffic light means caution, the light is

changing, a yellow warning light means something in your vehicle is changing or starting to malfunction. A red light means

stop, and so does a red warning light on your dash.

I will now explain some of the most common red indicators and what kind of problem they may mean to you. There are

always other possibilities, but these will be some of the most common problems.

The first light, arguably the most important, is the oil pressure light and a related light that your vehicle may have, an oil level indicator light. These lights both mean a problem with the engine lubrication system. The problem may be as simple as being low on oil, but that can also mean that you have an oil leak or your engine is burning oil. It can also mean a much more serious problem such as the oil pump pickup screen is blocked with sludge or that the oil pump has failed. No matter what, if your oil light comes on, get off the road safely and shut your engine off. Do not try to drive to the nearest service station or try to get home, that will probably be way too far and permanent damage has already been done!

Another very important light is the battery or alternator light. This light indicates a problem with the charging system. This

could be caused by a loose, worn or broken alternator belt, which can also cause other problems such as overheating or lose of power steering. It can also indicate an alternator malfunction. In either case, do not drive the car, get safely off the road and call for help.

A temperature light coming on is an indication that your engine is overheating.  You may also have a coolant level indicator which would tell you that you need to add antifreeze. If you temperature light comes on, it can also be caused by a loose, worn or broken belt. There also may be a bad thermostat or bad water pump. At any rate, do not drive an overheating vehicle, doing so will very likely cause a blown head gasket or other permanent engine damage.

Some vehicles come equipped with an automatic transmission warning light which indicates a problem in the transmission. This is usually a shifting problem, and can be caused by a low fluid level or a mechanical of electrical malfunction in the transmission control system.

The brake and ABS lights can indicate many things. It can be showing something as simple as low brake fluid or the

emergency brake stuck on. It can also mean on of the wheel sensors is not sending a signal to the ABS computer or it can be a failure in the computer itself. At any rate, if the light is on, the antilock brake system most likely will not function which means you will lose ABS assist.

Many newer cars have other warning lights or indicators such as tire pressure monitor systems that are designed to make

your vehicle safer.

The most important thing to remember is, IF THE LIGHT IS RED, STOP! If you are not sure what an indicator means, check your owners manual.

Most recent safety recalls:

9,345 2014 Kia Sorento FWD and

20,300 2013 Hyundai Santa Fe FWD

With 2.4L engine for RF axle shaft fracture.

239,000 2006-2010 Hyundai Sonata

& 2006-2011 Hyundai Azera

in northern states for corrosion of the rear crossmember.

370,000 2005-2011 Ford Crown Victoria,

Mercury Grand Marquis, and

Lincoln Town Car

in northern states for steering shaft corrosion.

If you own one of these vehicles, contact your dealer for further instructions on what to do.