San Carlos Auto Repair

Call Us: (650) 595-2277
Mon - Fri: 7:30 AM - 5:00 PM | Sat: 7:30 AM - 12:00 PM

Why is my tire pressure light on?

Why is my tire pressure light on?

The tire pressure monitor light first started showing up in luxury car in the late 90′s but now is standard in all cars sold in the United States as of Sept. 01. 2007. It is time to introduce you to the Tire Pressure Monitor System (TPMS) and the sometimes pesky tire pressure monitor light.

Tire Pressure Monitor Light

As we come out of fall and winter arrives, our temperatures begin to drop drastically over night. When it comes to our cars, steep temperature drops can trigger a sign of fall that we don’t welcome: a yellow or orange low tire pressure warning light.

We have good news for you, though. When your light comes on, your car is simply telling you that you need more air in your and this time of year, the warning is usually related to chilly nights.

Here’s what’s happening

  • Several vehicles that are 2000 and newer cars and trucks are equipped with a Tire Pressure Monitor System, which triggers your dashboard warning light when the air in your tires drops just a few PSI below the recommended tire psi.
  • Your tire pressure will decrease about 1 psi for every 10 degrees Fahrenheit the outside air temperature drops. (Likewise, it increases about 1 psi for every 10 degrees when the temperature rises.) If your tire pressure was last adjusted during the day or after just coming off the road, the air pressure could be related to 90 degrees Fahrenheit. So now, the temperature drops over night overnight temperature hits the low 40s, your tire pressure will drop down by 5 psi, almost certainly turning on the tire pressure warning light.
  • To remedy your low tire pressure light, a simply check or adjustment of the air in your tires is all that is required. You can do this at a local gas station or bring it to your local mechanic. There shouldn’t be a charge for this if you find a decent shop.
  • Make sure you let your mechanic know that the tire pressure light was on in the morning when it was cold. If you drive your car down to the local shop, the tire pressure will rise from where it was in the morning because the tires will heat up. Parking the car in the afternoon sun will also boost the tire pressure…falsely.
  • In most vehicles, your TPMS light will turn off once the tires are properly inflated.

If your light doesn’t turn off or if have questions about checking and adjusting your tire pressure, contact the team at A+ Japanese Auto Repair! We can set the tire pressures for you and can usually reset the light in a couple of minutes.

If Tire Pressure Monitoring Systems (TPMS) seem like overkill when it comes to automotive technology, consider this: A June 2012 study by the Rubber Manufacturers Association reports that more than 80 percent of vehicles on our highways have at least one under inflated tire, which can reduce safety and handling, raise your fuel consumption, and can wears out the tires faster costing you money. For more on tires… click here to our tire information page.

What should the tire pressure be on my car?

Written by Eric Sevim - ASE Master Certified Auto Repair Technician

A+ Japanese Auto Repair, Inc.

780 Industrial Road

San Carlos CA 94070


If You Are Using A Screen Reader And Are Having Problems Using This Website, please call A+ Japanese Auto Repair, Inc. (650) 595-2277 For Assistance.