Tire Pressure System not working.

[xray328]

I recently bought an '04 GTP and I don't think the tire pressure system is working.

I filled up all the tires to the same psi then drove around for a few days. I then reduced the air pressure on one tire to 15 psi and nothing happened. (no bells or whistles)

Any ideas?

[GeddyLee]

You bought it used I am guessing? Did you buy it from a Pontiac dealer or what? If it is used, was it modified in any? There could be a couple possibilities here. One the previous owner disabled it, or two possibly check the fuse box that controls that feature to insure the fuse is not blown or missing perhaps? I am not sure if that is something in the PCM that can be disabled or enabled, but that is also worth looking into. And if you got it from a GM dealer, I would haul it back there and pitch a ***** if all else fails

Just a couple thoughts on that.

[Sabrewings]

Is your system the kind that uses valve stem pressure sensor, or wheel speed sensors (poor man's system). Mine uses the latter and goes off with repeatable results (and without my intention one time) at exactly 10PSI lower than the rest.