Low Tire Pressure Idiot Light Came On...

The system compares a baseline number with the current pressure and flags if the difference exceeds a certain limit. You can reset the TPMS by pressing a button under the dash & whatever pressure the tires are at becomes the baseline. Maybe the system was set at hot temp and dropped below the limit when the car was cold in the morning. You can try reset it in the morning & see if it happens again.

 

It could be battery failure in the TPMS sensor inside the tire.

 

It's a bit more complicated than just pressing the button; check the manual for the procedure.

 

I have aftermarket sensors in my summer wheels/tires and one of them is starting to act up. The indicator is never lit when I'm near the Belle Tire store, though.

 

In most cars the spare also has a TPMS, check that too maybe. just a wild guess.

 

I'd let the dealer know, just make sure it get's on the toyota computer, if you do have a sensor problem it'll already indicated, might make it easier down the road. I like the check the spare idea but doubt it, must just be another digital electrical gremlin, if after 7 or 8 restarts it's still there it's a problem... I'd be tempted to unhook the 12v for a reboot of the system but before doing that, if it's there in the am the dealers OBD11 reader will be free and thorough.

 

Check the spare, did you have the tires changed lately? More often than not the sensors get cracked when removing/installing tires, the sensor is right under the valvestem. Aftermarket tire shops will kill far more sensors then are found defective.

 

As a Jeep Wrangler Owner TPMS is the biggest pain in the nice person.
First thing we do is spend $100 on a tool that can disable the sensor.
Technology we did not need.

 

I took an elderly friend's nine-year-old Cadillac to the dealer for service a few months ago, and one of the problems was one or two of the sensor batteries were weak. They worked when on the rear of the car, near the receiver located in the trunk, but failed after the tires were rotated. The tech said they are meant to last only about five years, so these were on borrowed time. You can't replace the batteries, but have to buy new sensors for $125 each, and then pay for labor to replace them, balance the tires, etc. We decided to ignore the messages and check the tire pressure the old-fashioned way. The car has since been donated to a charity.

 

How long do the batteries last in the Toyota sensors?

Mike

 

Don't do anything with it. Take it the dealer as you have a 2012 and I assume it's under warranty. A faulty sensor is my bet.

 

I'm a new fan of the tpms in Toyotas. The sensor lit up a couple of days ago, all the tires looked ok, but I took out my trusty tire gauge and the pressures read 32, 34, 34 and 15. Inspected to 15 tire and found a lovely nail right in the middle of the tread. Pumped up the 15 to 32, drove to the tire shop, had the tire fixed and I'm on my way. The shop balanced all the tires to the recommended 33psi. Beats driving on that low tire till I ruined it! .

 

Who recommended 33?

 

Note that he has some 'Other Hybrid', not a Prius, so don't go by the Prius recommended numbers you remember.