3. If the shop inadvertently breaks a TPMS sensor and cannot immediately find a replacement, can the shop temporarily replace the valve stem and return the car to service?

According to NHTSA "as a general matter, a violation of the ‘make inoperative’ prohibition does not occur until a repair business allows or intends a vehicle to be returned to use...this would be true regardless of whether arrangements have been made for future repair."

"While there will be some debate over the circumstances related to inadvertent damage, there are no questions regarding the release of the vehicle," said Rohlwing. "If the actions of the service provider made a functioning TPMS inoperable, then it cannot be returned to service until the problem is solved."

So according to the NHTSA, if the TPMS sensor is already broken when the car comes in and I can't get a replacement sensor for a couple of days, I can put in a black rubber valve stem and release the car to the customer. But say the TPMS sensor breaks while I'm working on the assembly, and I can't replace the sensor for a couple of days, because the part is dealer-only. This happens even to the best of tire techs – the sensors are wicked fragile and corrode like nobody's business. Many times a sensor will come in corroded and the valve stem will snap when we try to take it off. Or somebody put a brass valve core in a nickel stem, and now it's rust-welded into the stem and can't be removed without damage.

Even though I did not deliberately break anything, according to this interpretation, I now have to keep the customer's car until I can get a dealer-only sensor! Oh, I just can't wait to have to explain that to a customer. Thanks NHTSA!

I personally would like to see some further clarification on what constitutes damage caused by the shop. If a TPMS sensor is corroded beyond repair but still functioning electronically, and the shop damages the sensor while working on it, is this damage that occurred before or after the customer came in for service?

4. If the shop performs a service and turns over the car to the customer, but the TPMS Malfunction Indicator Light comes on, indicating an inoperative system after the customer has left, has the shop violated the “make inoperative” provision?

According to NHTSA, "The mere illumination of the malfunction indicator lamp after the vehicle has been released by a motor vehicle repair business to the driver would not itself be a violation of the ‘make inoperative’ provision."

"Based on NHTSA's response, we are advising tire retailers to document the status of the TPMS before and after any tire or wheel service," concluded Rohlwing. "If the electronic TPMS relearn or diagnostic tool includes the functionality to produce a print-out on the status of the system, we recommend that retailers give a copy to the consumer and retain a copy for their own records following service."

Let's be clear here: The NHTSA essentially admitted in the 2005 Final Rule that they did not have the legal authority to force car owners to buy replacement sensors or extra sensors for replacement wheels. But what they can do is make businesses responsible for forcing car owners to do so by fining them $10,000 if they're not willing to stand in as the bad guys. Given that we've spent the past 6 years dealing with the monstrous kludge that is TPMS in the first place, it just seems like a huge slap in the face.