- Car Care & Maintenance
Low Tire Pressure Warning Light Is On
Is Your Low Tire Pressure Warning Light On?
So is the low tire pressure warning light on, or is your TPMS light on? There is a difference, and the repair is much different depending on which warning light is on. If the TPMS light is on, most likely you have a problem with the tire pressure monitoring system like a malfunctioning tire sensor. If all tire sensors are working properly, you may have to dig a little deeper to figure out what's causing the light to come on, you may even have a faulty control unit, but let's not get to deep yet.
The NHTSA (National Highway Traffic Safety Administration) regulations state that the low tire pressure light indicator must come on when the tire pressure drops 25% below the listed recommended inflation pressure. Some manufactures have stepped it up a notch and have set their tolerances to no more than a 20% drop in pressure before the light comes on, so check your owner's manual for more information.
Low Tire Pressure Warning Lights
What Causes The Low Tire Pressure Warning Light To Come On?
If the low tire pressure warning light is on in your vehicle, the warning light with the icon of a tire with an exclamation point in the middle, the most likely cause is low tire pressure. This warning light could be caused by either an obstruction in the tire like a nail or screw, it may be caused by neglect (not setting tire pressures to manufactures specs at every oil change or every two months), or it could be caused by the temperatures outside dropping 50 degrees.
All tires, even tires in good condition, lose air for a number of reasons, but mostly because tires are porous. It's common to lose at least 1.5 psi per month naturally, but, there is also scientific evidence that tire pressures drop with colder temperatures, so you could expect to lose at least 1 psi per every 10 degrees drop in temperature.
Driving With Low Tire Pressure is Dangerous
Low Tire Pressure Warning Light
Don't just fill your tires with air, know your tire pressures.
Here's a scenario;
Let's say you took your car in for an oil change in late August, and the temperature outside is a balmy 85 degree. The mechanic sets the tire pressures in your vehicle to 32 psi because it's recommended by the factory sticker in the driver's door jam. Fast forward to late November, early December, and the temperature outside has dropped to 30 degrees (something that is very common in New England) and your low tire pressure light comes on.
You bring your vehicle in for its next oil change and the mechanic tells you that the tire pressures are all at 24psi, not only have you lost tires pressure naturally from being porous, but you have also lost tire pressure because of the 55 degree change in temperature. It's always best to set the tires pressures to the cold inflation settings just before the cold temperatures set in, this will help prevent the pesky low tires pressure warning light from coming on so often.
What To Do If Your Low Tire Pressure Warning Light Comes On
If your low tire pressure warning light comes on, don't panic! Here are some steps you can take before you bring it into the garage;
1. Do a visual inspection of all your tires; make sure one is not flat.
2. Check all your tires for proper inflation, about 32 psi in warm temperatures, 35 psi in cold temperatures.
3. If one tire has lower tire pressure then the other three, check it over for a nail or screw in the tire tread.
4. If you want to look for the leak, use a spray bottle with a water and dish soap mixture, spray the complete tire and rim, and then watch for bubbles.
5. If the TPMS warning light is on, bring it to the dealership because there is something wrong with the tire pressure monitoring system.
Low Tire Pressure, Low Fuel, it's All The Same?
Think of it like this, the low tire pressure light is like a low fuel light, when it's on, it means you need to put air in your tires, just like you would put more fuel in your car if it was low on fuel. Ultimately, it's the driver's responsibility to keep an eye on the vehicles tire pressures, and having low tire pressure sensors in each tire will help you maintain proper inflation.
If you would like to take it one step further in trying to prevent the low tire pressure light from coming on, you could try filling your tires with Nitrogen. A lot of dealerships and tire stores have had Nitrogen filling stations installed since the Tire Pressure Monitoring systems have been implemented. Filling your vehicle tires with Nitrogen will help with the fluctuation in tire pressures because Nitrogen has less H2O (water) in it than regular air.
With the Nitrogen being dryer naturally, there is less fluctuation in tires pressures, it's not a perfect system or a permanent fix, but it does reduce the visits to the air pump or garage, and it also comes with a price, usually around $100 for lifetime Nitrogen fill, but ask your dealer for more information.
Find the right tire pressure sensor for your vehicle at Amazon
Questions About TPMS or Your Low Tire Pressure Warning Light?
If you have any questions about your low tire pressure warning light, TPMS light, or Nitrogen, feel free to ask and I will be glad to answer them as best as I can.