We know a couple who recently took a fall weekend trip to a pumpkin farm. Before they left, they filled up the gas tank, buckled in the kids and hit the road. They weren’t too far from home when they had a bit of a scare: Their dashboard began to glow with a yellow light that looks like an exclamation point with brackets.
They stopped at the nearest service station to check their owner’s manual and learned this was the tire pressure light, which was telling them one or all of their tires could be low.
Fortunately, the man at the service station was able to help them check and adjust their tire pressure, and they were off again to continue on their pumpkin-picking mission.
Why did the warning light go on?
Federal law required that all passenger cars and trucks beginning in model year 2006 be equipped with a Tire Pressure Monitoring System or TPMS. This system alerts drivers when the tire pressure dips about 25 percent below the recommended specification. Some vehicles will trigger the TPMS light at less than 25 percent.
With fluctuating temperatures as the season changes from summer to fall, dramatic changes in temperatures from daytime to nighttime can cause low tire pressure warnings, some legit and some not so legit.
What causes tire pressure changes?
Aside from having a nail or other puncture “wound” in the tire, the ambient air temperature can affect your tire pressure. For every 10 degree change in air temperature, your tire pressure will fluctuate about 1 psi.
If you or your auto shop last set the tire pressure when it was 90 degrees outside, imagine what it drops to when the overnight temperatures fall into the mid-40s. Your tire pressure could be changing 4-5 psi at night, which can cause the TPMS light to go on.
What should you do when your tire pressure light goes on?
- Check and adjust your tire pressure. Ideally, do it in the morning before the temperatures heat up and causes a false bump to the psi level of the tires.
- In some vehicles, your TPMS light will turn itself off once you’ve properly inflated the tires. In others, you may need to reset it. Check your owner’s manual for instructions. If your light is persistent, let Auto Lab know. We can help.
We’ll make sure the system is operating properly, and we can reset the light for you. In most cases, we can reset it quickly.
If you have any questions or the TPMS light is on consistently, call us at 847-367-4488, schedule an appointment online or stop by.
Driving with underinflated tires may cause lower fuel economy, reduced safety and faster tire wear.