TPMS light keeps coming on... ???

[blue2turbo]

Alright so I dropped the car off at the dealer to have them fix the windshield wiper cowl squeek (got them to just put on a whole new one for free (naughty))... as well as see what they could do about the interior squeeks and replace all 4 of my rotors since they were all warped (11,800 miles... caught it just in time). Well after they give me the car back, that night the TPMS light comes on. So we drove home, parked, and didn't drive it again until the next day to take it to them. They made the light go out, and didn't explain how. Well we go on vacation and come back, and about 1.5 weeks later, it comes back on. Take it to them again, and they make it go out and give the car back in like 5 minutes, no explantion. Well yesterday it came back on again. I checked all the tire pressure, its fine... so why does it keep coming back on?

Mind you, the dealer is about 30 minutes from my house... w/no traffic... traffice... 45 min-an hour... so these trips back and forth are wasting my time and killing my gas. Any ideas?

 

[SuperStretch18]

Did you check your tire pressure yourself? Pressure fluxuates with temperature, so it is possible that it is below spec before you drive and when the tires heat up, the gas expands enough for the light to go off. Same thing cold day vs. warm day / day vs. night.

The dealer probably just filled the tires with air, so if you have a slow leak, it will just come back...

 

[turbobst]

Possible slow leak, fill your tires with about 2-5 psi extra than what you normally put and see what happens.

 

[blue2turbo]

Did you check your tire pressure yourself? Pressure fluxuates with temperature, so it is possible that it is below spec before you drive and when the tires heat up, the gas expands enough for the light to go off. Same thing cold day vs. warm day / day vs. night.

The dealer probably just filled the tires with air, so if you have a slow leak, it will just come back...

I keep a tire pressure gauge in the car... actually in all of my cars... mostly for when I go on long trips, I check the pressure each time I fuel up.

No leaks in the tire, I checked the pressure last night when it came on, checked it again when I drove home ~35 minutes of driving, and checked it again this morning, and there was barely any fluctuation. ~40-45 degrees last night, ~25-28 degrees this morning.

I am calculating the pressure recommendations off what is written in the doorway of the car. The second time it happened, like a week ago, I decided to test some things out, drained the tires about 3 PSI each and drove around, light stayed on. Added 2 PSI above recommendation, light stayed on, then set them back to recommended and the light still stayed on.

I thought about unplugging the battery to reset the ECU, but if there is problem with the system, a bad sensor or something, I don't want to keep beating around the bush to make it go away, I want it fixed.