I took a very enjoyable 120 mile round trip in the Challenger yesterday. After about 40 miles the tire pressure warning light came on for about five minutes. It went off on it's own. I stopped at the first service station and checked all the tire pressures and they were all at 32 PSI. The light never came on again.

 

You probably have a sensor about fail or something temporarily interfered with the signal.

 

Not sure where you are located, but I've seen in different vehicles when the pressures are set at 32, and you get a cold night, science takes over and you can "lose" a few pounds which will turn on the light. After driven and warmed up, the tires "make" more pressure, and the light will go off. If it was on a cold morning, you can set the pressures to 35 with no issues, if it was while it was warm, you may have a sensor going bad.

 

I had my light come on also about a week after getting my R/T . Was on the interstate headed to the dealer for some paper work that needed to be signed. I pulled over and the tire's looked ok . So I drove to the next exit . Was showing 31 on the gauge I had . A new Snap on dial gauge with about a foot of hose. I drove on to the dealer as the light was still on . They aired the tire's up to about 34 lb. It was in the teen's that morning . They said you had to drive a few mile's after airing the tire's up for it to reset . Any way the light went out . They said you have to have 33 lb in the R/T . And light would come on if it dropped below that . They had sold several new R/T Challenger's and said they'd had several come in with the air below 33 . I laughted and said I guess they don't want you to have a low tire at 160 mph. My wife's 06 300 C doesn't come on till drop's to 26 lb. Her light came on a few morning's ago with temp was in low teen's.

 

The temp was in the upper 60's and I had driven over 40 miles when my light came on but my tire's are inflated to 32 PSI. This is the PSI. as delivered. My car has 1200 miles on it. The sticker in the door say's 32 pounds for the R/T 18 inch 55's. I agree that a couple extra pounds will not hurt. So I will raise the pressure to 35 PSI.

 

My R/T's light comes on at 25lbs. I found that out when my left rear was losing air due to a valve core not being seated. I had to air it up to 33 before the light went out. I am running the rears at 30 for traction and never get the light.

 

These things work wirelessly, right? Can they receive signals from other people's cars? I mean, in traffic your receiver can be closer to a neighboring car's tire than it is to your own rear tires if the receiver is positioned under the dash. Or, are they keyed specifically to the transmitters in just your car. That seems unlikely though with the limited number of frequencies available. All moot if the system isn't wireless, though.

 

I have the 20's with the optional Good Year all season . But don't know if that makes a difference.

 

The system IS wireless. The TPMS sensor is attached to the base of the valve stem. It sends an RF signal to report pressure. When the sensors are first installed (and when they are replaced) the sensors are activated and the computer is programmed to recognize the sensor ID. This is the part that keeps it from reading another car's signal as you are driving alongside. On a system that displays each tire's location and pressure individually, you need to reprogram each time the tires are rotated. For systems that simply set a generic warning light and not position/pressure, you do not have to reprogram after a rotation.

 

Good info wagonmaster. This guy is not a rookie ^^^^^^