The vehicle is equipped with air pressure sensing tire valves that are made of a substandard metal that corrodes and brakes. The first time I had an issue the tip of the valve broke and the tire could not be inflated. The second time, today, the valve broke in half and the tire deflated in about ten seconds. Fortunately, the vehicle was not moving. I replaced the part at the dealer the first time and they stated it was a known issue with the part and that a new part had been made that would not corrode. The fact that it has happened on two of the four sensors shows this is not an uncommon problem. Clearly such a blow out at highway speeds would have put my life and the lives of those near me in jeopardy.

- Pittsburgh, PA, USA

While checking the tire pressure on a customer's vehicle, the tire valve on the TPMS sensor broke.

- Pleasanton, CA, USA

The automotive oil change association (aoca) represents the fast lube industry, with more than 3,500 locations in North America, servicing more tires than any other organization. Over the past several months members reported an increasing number of problems with tire pressure monitoring systems (TPMS) ' and they are getting worse. Conventional TPMS's measure tire pressure at the valve and use a radio frequency to transmit the data to an antenna on the side of the vehicle. The quality of these valve stems is so poor that car care professionals know - if they check the tire pressure, it is likely the valve will break and they will incur the cost to replace, about $110 per unit. Specifically, the 2008 Jeep Grand Cherokee, and the 2008 Chevrolet equinox, have aluminum valves stems; these easily corrode, become brittle, and break at the touch. They also have a plastic cap. If this plastic cap is improperly seated, or replaced by an aftermarket cap containing brass, or brass thread inserts, it leads quickly to galvanic corrosion; the result- the cap fuses to the valve stem. Attempt to remove the cap, the stem breaks. The driving public is being 'trained' to trust these monitors for accurate tire pressure. Properly inflated tires reduce the potential for life-threatening blowouts, enhance handling, improve fuel efficiency, and prolong tire life; lowering the cost of ownership. These systems are too fragile to continue using them in passenger vehicles without addressing the durability. As these systems age, failure will increase 100%. TPMS units are spec'd out by oem's- manufactured by siemens vdo (acq'd by Continental ag in may '07). Aoca has made many inquiries to see if these units are intended to be recalled or redesigned'the resounding answer is 'no'. if oem's do not change the spec's TPMS's will continue to be poorly made. Aoca asks NHTSA recall these units to protect the consumer, and people maintaining the tires on vehicles.

- Dallas, TX, USA