Have you seen a light on your car's instrument panel that looks like an exclamation point in a horseshoe? What the heck does the symbol mean and what the heck do you do about it? It is the TPMS - Tire Pressure Monitoring System - indicator.
It is the single most misunderstood and maligned trouble light you will see on your instrument panel.
A number of issues with today's cars and and the people who service them come gift wrapped in this one symbol.
But that will be the subject of a separate article.
Here we will simply discuss the merits of the TPMS light.
This light is described variously as: •An exclamation point in parentheses •An exclamation point in bracket •An exclamation point in a horseshoe •Flames - destined to be a classic •An exclamation point in a cup •And, a real favorite, a candle in a glass! Never has anyone called and said "I have an exclamation point in the cutaway of a tire" - which is exactly what it is! Yet, it is maligned by drivers and service personnel alike, who all too often believe it is nothing but a pain in the neck.
But, in truth, it is doing its job, calling attention to the fact that the pressure in one or more of your tires is low.
Addressing the issue when it comes up will save you money on tires by extending their life and in gas by reducing rolling resistance.
The indicator light suggests four possible scenarios: 1.
All the tires are low on air (check the spare too).
This occurs seasonally as the weather cools, and possibly several times.
Solution? Check the pressures and inflate your tires properly.
2.
One tire is low.
This likely means a nail or other fault causing the tire to leak slowly.
Checking all of the tire pressures will reveal a single tire to be low.
A qualified service facility will be needed to address the problem.
3.
The system needs to be reset.
If you've recently had the tires rotated or replaced, check with your dealer about resetting the TPMS system.
4.
If the light is flashing, there is a fault in the TPMS system, which your dealer will have to resolve.
In the first three cases, the light is simply illuminated, not flashing.
If you must drive before addressing the light, please do so carefully...
under inflated tires are a potential hazard.
Your tires are the only thing between you and the pavement.
The light will go out after the proper tire pressures have been restored and after a bit of driving.
And by the way, the light will also come on if a tire blows, but the blowout will likely have your full attention...
So please, show this light some respect! Its doing its job, even if you see it illuminated on multiple occasions during year! Your tires need the attention.
Now if every car could tell you which tire and the exact air pressure...
Note that there are a handful of cars that use use an alternative symbol instead, so be aware! Its still a cutaway of a tire, but features arrows pointing to a dot inside the tire instead.
Somewhere along the line it was decided that the exclamation point would be more easily understood.
Our next article will discuss how too many of the warning symbols shown on today's instrument panels assume too much of today's information-overloaded drivers and do everyone a disservice.
The International Standards Organization (ISO) establishes symbols for use on controls, indicators and telltales applying to passenger cars, light and heavy commercial vehicles and buses, to ensure identification and facilitate use.
It also indicates the colors of possible optical tell-tales, which are supposed to inform the driver of either correct operation or malfunctioning of the related devices.
The American National Standards Institute also has a hand in this.
To date, the ISO has defined over 220 of these symbols.
220, and growing! They are supposed to be identified easily by all people everywhere regardless of language and background.
But all the good intention - not too mention a good deal of time, effort and money - has resulted in far too many of the symbols mean absolutely nothing to the average driver.