2008 GMC 2500 HD. I previously had a tire light on and service tire monitor system warning. I just installed new rims and tires because I needed them and my hope was to extinguish the light as well. Not so. The sensors checked out fine by Discount Tire and read correctly with their little hand held thingy. However, I now still have the light and its saying that all four tires are low on pressure. The tech said it could take as many as 50 miles for the computor to re-learn the pressures. On my SS Trailblazer it did it as soon as I pulled out of the lot. Anyhoo, they think it might be the computor. I suggested to them that I dis-connect the neg battery terminal to "re boot" the system. They said that might work. Anybody else run into this? What should I try? Thanks. Ocho

its not supposed to take that long. so what does your pressure say and what is the recommended pressure on the door tag?

Their at 40 psi door tag, says 50 for front and a whoppin 80 for the rear.

If your TPMS warning light flashes for about a minute each time you start up, the TPMS has a malfunction. If is not flashing you should inflate to the recommened pressures and see what happens. I would triple check that 80 psi number.

I know. Freaked me out too. its states 80 psi in 2 places. The actual door jamb and the pillar where the door strike is located. The warning light does not flash. It comes on and stays steady and the DIS says "check left front tire pressure" then makes the circuit thru all 4 tires. Ill run the front up to 50 to test the theory. Dont want a mouthful of rubber and steel this day. Btw, the tires do state the max psi is 80 psi on the sidewall, so I guess it would work. Just kinda scary!

Just ran all tires to 50 psi. Rears still showin low. Fronts good. So here goes. Up to 60 then 70 then 80 to find the majic number. Wish me luck!

It'* an HD pickup, it wants high PSI numbers because that'* what its designed to handle.

Voila, the majic numbers are, drum roll please, 50 in front and 70 in the rear. Light out. But thats crazy to calibrate a tire to run around on 70 psi unloaded. Bet it doesnt ride well! sheesh!

I know. I guess i needto quite whinning.

Uhmmm ... let'* review this. You are running the fronts 10 psi low, and the rears 40 psi low and the TPMS is telling you the pressure is low. Go figure.

I think we found the problem ... there is a loose nut behind the steering wheel.

Just yanking your chain of course. I have the same concerns about running tires up to 80 psi, but it looks like that is where they belong.