What is the Horseshoe-shaped Dashboard Warning Light?
Its cold weather time again and time again to speak about the Tire Pressure Monitoring System (TPMS), and its associated warning light(s). Every year several million more drivers who have recently upgraded their cars will encounter the light for the first time.
These are two versions of the TPMS light, and either one is easily the most misunderstood warning light you’ll find on your instrument panel. And the fact that its shaped like a horseshoe doesn’t help.
First, unlike other yellow/amber lights, there is nothing wrong with your car — it presents you information about your tires and likely as not there’s nothing actually wrong with them either.
Why the Light Is On
There are two possible reasons why you are seeing this light. First, as the weather cools the most likely possibility is that all four of your tires are low on air (and/or the spare!). The second possibility is that one tire has a leak of some sort, but we’ll return to that in a moment.
Air expands when heated and contracts when cooled. Air that has cooled and contracted in your tires leads to reduced tire pressure. The warning light comes on and air needs to be added to your tires. Its important to note that air has not actually leaked out.
But the warning light does not discriminate between cooling air and actual air leaks. It comes on if one tire is low or all four is low, so more information is needed. Your model may or may not include a display option like the one shown. It is a read out of the tire pressure in the individual tires. If all four tires read roughly the same, within a pound or two, the warning light is the result of seasonal cooling.
And while on the subject, a thought for manufacturers. Every vehicle equipped with the tire pressure warning light simply must be equipped with this display. Leaving your customers in the dark by displaying the warning light only is unacceptable to us.
Now, if one tire is several pounds lower than the others, 5, 6 or 7 pounds or more, that tire is leaking and needs to be serviced as soon as possible.
If your vehicle is one that features only the warning light, the tire pressures need to be checked by hand to determine the cause — a single leak or seasonal reduction in all four.
If you’re not comfortable checking your tire pressures or with filling them, the good news is that pretty much every tire store, repair shop or car dealer will fill them for you at no cost. Its simple for them to do and they make a friend in the process, meaning more business from you down the road. Please drop in on one of them.
If you are comfortable with checking your tire pressures and adding air, by all means do so. But you will first need to know the required tire pressure. Look for a label just below where the driver’s door latches. The required pressures will be shown. They will match left to right but will likely be a little different front to rear. Set the pressure on the pump and trust it. It will stop pumping once the proper pressure is reached. You may also find yourself using a pump with a built in gauge. Trust it as well and be sure to add your spare tire to the routine.
Each tire valve has a cap that needs to be unscrewed and removed. Don’t lose it — it keeps water and dirt out and will keep the valve from developing a leak.
Learn more about this warning symbol here.
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Remember that only proper service and repair procedures will ensure the safe and reliable operation of your car. In addition, proper safety procedures and precautions, such as the use of safety goggles, the right tools and the equipment should be followed at all times to eliminate the possibility of personal injury or improper service which could damage the vehicle or compromise its safety.
These posts are for information sharing purposes only, and should not be used in lieu of an OEM service manual or factory authorized service procedure. We are not in the auto repair business nor do we publish automotive service manuals. Nothing we include on these pages and posts has been reviewed, approved or authorized by any vehicle manufacturer.
Technology is always changing and what is current and accurate today may be literally out-of-date and inaccurate tomorrow. And when it comes to the current state of flux in the auto industry, nothing is more true.
The author has 25 years of automotive experience and has assembled the most extensive collection of symbols and warning lights anywhere (over 1,000!) and can help you open and start any keyless start car with a dead key fob battery. BA, St. Joseph’s College, ME: MS, Rensselaer Polytechnic Institute, NY
This is a Shift to Park Dashboard Warning 
These are all Driver Monitoring System Dashboard Indicator 
The first of the two additional indicators, both seen in 
The 
This is an Idle Coasting Indicator 
This is a Roll Away Potential Indicator 
This is a Launch Control Indicator symbol. It is seen when Launch Control (LC) is enabled. The indicator is seen only as the LC acronym. Launch Control is a feature that can only be used in a straight line and is specific to vehicles that can be taken from the street and raced on a drag strip.
The Ever-growing Dashboard Symbols Saga…
A Short History
Some 13 years ago when we started this site, we believed that the driving public had no idea what it was up against in trying to understand the warning lights and dashboard symbols being thrown at them by their car’s instrument panel.
We had no idea where this would lead.
The Symbols Count
We now host 986 (now over 1000!) of warning lights and indicators! Nine hundred and eighty six! Most are image-style indicators but there are also nearly 200 text indicators.
Every year we update the warning lights from 47 manufacturers who have or currently do sell vehicles in North America and we made the mistake of counting them last week.
If this sounds absurd to you, well we couldn’t agree more. The table below illustrates the problem.
If you count them, you’ll find 22 different images representing suspension systems. Essentially every manufacturer gets to choose an image style to use. Some include text, which is helpful, and others include a sketch of a vehicle, which is also helpful.
But note the pair that look like a hat with an arrow inside and others that don’t bear any resemblance to anything an average person can relate to!
Idiot lights, or tell-tales, as they are known only in the industry, were designed to help drivers who didn’t understand how to read a gauge and to get your attention. To those who actually did know how to read the gauges, and watched them like a hawk, the tell-tales came to be known as Idiot lights. And the term stuck.
However, in today’s vehicles, there could never be a corresponding gauge to compliment a Check Engine light, or the ABS (anti-lock brake) light for example. There actually could be a pressure gauge associated with air suspension systems represented by some of the symbols in the table. But the industry is long past gauges.
There may be 30 to 40 picture or text tell-tales on a modern instrument panel, each connected to some system in your car. We’ve counted as many as one hundred in some models! And they may illuminate in twos and threes if a problem is detected. That is, a problem with one system causes other systems that are dependent on the first to be shut off. Each of those systems will have an associated, and now illuminated, tell-tale. Today, a driver needs to be an automotive prodigy to know what’s going on.
We’ve called on the industry to trash this near useless system in the past in favor of the car actually telling a driver what’s up and what they can and can’t do. The information is in the vehicle’s computer, but is accessible only to technicians with the proper equipment.
There has been some talk of simplification, but we update the symbols in new cars every year, and when we’re done with 2024, we can assure you that another 30 to 50 symbols will be added to our pages.
We think you, the driver needs help and we are here to do just that. We ultimately hope that the way vehicles communicate with drivers is changed. In the meantime, if you are confused by the symbols that show up on your instrument panel, bookmark this site. We’ll do everything we can to help you not feel like an an “Idiot”!
——————————————————————-
Remember that only proper service and repair procedures will ensure the safe and reliable operation of your car. In addition, proper safety procedures and precautions, such as the use of safety goggles, the right tools and the equipment should be followed at all times to eliminate the possibility of personal injury or improper service which could damage the vehicle or compromise its safety.
These posts are for information sharing purposes only, and should not be used in lieu of an OEM service manual or factory authorized service procedure. We are not in the auto repair business nor do we publish automotive service manuals. Nothing we include on these pages and posts has been reviewed, approved or authorized by any vehicle manufacturer.
Technology is always changing and what is current and accurate today may be literally out-of-date and inaccurate tomorrow. And when it comes to the current state of flux in the auto industry, nothing is more true.
The author has 25 years of automotive experience and has assembled the most extensive collection of symbols and warning lights anywhere (over 1,000!) and can help you open and start any keyless start car with a dead key fob battery. BA, St. Joseph’s College, ME: MS, Rensselaer Polytechnic Institute, NY