my tire pressure low light is on. the tires were all at 35 psi. i looked in the door and it said that it needed to be 30. i put them at 32 which is normal tire pressure but the light is still on. any ideas
The actual pressure isn't the problem, you need to reset the light. First put them at the desired pressure then hold the reset button in until the light flashes and goes out. If the light stays on, there is a problem with the system.
I think the speed sensors for ABS/Tract. Control (located on each of the wheel hubs) are also utilized by the Tire Pressure Monitor. When comparing the circumference of four wheels while traveling down the raod, they should all be equal rpm. If one tire loses air, the circumference changes (speed differential) with respect to the other three tires. I'm not 100% sure on that theory though, I'll have to do some more research.
That is exactly how the system works When you re-set the tire pressure monitor it clears the computer of previous tire rotation speeds. After driving a few miles the computer re-learns the new rotation speed and is able to tell if one is going low. 10 pounds difference in any one tire should put on the light. It is a good idea to re-set the monitor every time you adjust the tire pressure