TPMS: It's finally getting better

Oct. 15, 2010

I have to admit that I struggle when coming up with titles for my articles. I’m so bad that the editors at MTD have my unconditional blessing to change the title and they usually do. But this one is different because I’m confident it’s the perfect synopsis of where the industry stands with tire pressure monitoring systems, or TPMS. I’ve waited a long time to say the words, “It’s finally getting better,” mainly because I didn’t want to mislead anyone or subject myself to professional and public ridicule. But I think we’re finally reaching the stage where things are improving, and some recent events support my optimism.

Let’s start with public perception. After years of beating my head against the wall trying to get the TPMS industry to recognize that there will be no market for replacement sensors unless the driver sees value in the system, it appears that some of the leading manufacturers are stepping up their public relations efforts.

Schrader International has launched a new consumer Web site that is designed specifically for drivers who have questions regarding TPMS: www.TPMSmadesimple.com. It’s incredibly easy to navigate, and I especially like the Bridgestone Technical Center Europe S.p.A. video that shows the difference in handling when the tire pressure is below the placard. It helps customers get a mental picture of the difference between proper and improper tire inflation.

Another section of the Web site that I think can be of great value to tire retailers is the Driver’s Forum. This is a collection of one-page testimonials that can easily be printed or e-mailed to customers. Consumers need repeated positive reinforcement regarding the benefits of TPMS, and this type of information is vital to changing public perception. Hopefully Schrader will continue to seek out stories like these so retailers can constantly update the messages in the showroom or the customer’s inbox. It should also spur a reader or two to implement the idea on a local level and get similar testimonials from customers who have had positive experiences with TPMS.

Tire dealers should be doing everything they can to promote these Web sites to every customer that comes in with a TPMS on the vehicle, even if they don’t require any maintenance on the system. If drivers are educated on the benefits of properly inflated tires and recognize that TPMS is the best protection against a grossly underinflated operating condition, then they will be more willing to purchase the replacement parts and sensors. It takes a little extra time and a little extra effort to explain why the service pack needs to be replaced and why the best insurance to protect an expensive tire from a run-flat condition is a new sensor. But the payoff is increased sales and better profits when the sales personnel can sell the advantages of TPMS to a consumer who is already educated to some degree.

While I will admit that it has taken some time for tire dealers to embrace the reality of TPMS and the fact that it’s not going away, there are still a significant of number of obstacles for the average business. Perhaps one of the most daunting tasks is to somehow manage the 120 different sensors for all makes and models. Looks are definitely deceiving in the TPMS industry, so the identical dimensions and color do not necessarily mean the electronics inside the sensor are identical. The Tire Industry Association (TIA) developed a reference chart that lists the part numbers for all makes and models of domestic and foreign vehicles. With this chart in hand, the technician has part numbers from the OE manufacturer and companies like Schrader International, Dill Air Controls Products, National Automotive Parts Association (NAPA), Orange Electronic Co. Ltd. and Myers Tire Supply Co.

None of this changes the fact that with multiple original equipment and aftermarket suppliers, one vehicle can have five or more different part numbers for the service pack and another five different part numbers for the replacement sensor. In most cases, the dealers are stocking sensors just like they stock tires; they carry enough inventory to handle the most popular models and then order the rest. Or, they don’t carry any inventory and rely on local suppliers to deliver the parts on an as-needed basis. Either way, it’s an imperfect and inefficient system that is destined to fail on any given day of the week and tie up thousands of dollars in inventory. And while TIA has made it a little easier with the TPMS Relearn Chart that lists the relearn summaries and part numbers, it still doesn’t solve the problem when the tire is off the rim and none of the local suppliers have a new sensor in stock.

Two sensor manufacturers have stepped to the forefront and created universal sensors that are capable of operating on a large number of different vehicles. Last year, Schrader introduced the EZ-Sensor, what the company calls “a programmable tire pressure monitoring sensor that can be programmed to function across different vehicle makes and models.” One of its largest competitors, Continental VDO, just recently announced the “VDO REDI-Sensor, a true multi-application TPMS sensor that offers the aftermarket a credible solution to the challenges of stocking and servicing TPMS.” While these prime examples of marketing-speak may appear to be two different companies offering the same thing, there are some distinct differences.

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First, the Schrader system starts with a “blank” sensor that must be programmed with a Schrader 21230, NAPA 92-1525, Bartec Tech400 or OTC/SPX Service Solutions Genisys TPR relearn/scan tool. Schrader says it can cover 90% of the domestic and foreign market with one blank sensor and the remaining 10% with another, so dealers would need to inventory two different sensors. Since the EZ-Sensor is blank, it’s never out-of-date because any change in protocol by an OEM can be accounted for with a corresponding change in programming for the relearn tool. As a result, this system must include annual updates to the relearn tool software in order to be effective. It also uses the same design as the original equipment rubber snap-in sensor, so there are no extra parts to stock other than the rubber snap-in TPMS replacement valves already inventoried. And a metal clamp-in valve is available for customers trying to match clamp-in valves on the remaining assemblies. The only downside that I can see to the EZ-Sensor is that a specific relearn/scan tool is required every time a sensor is replaced, but progressive dealers should have one anyway, so it shouldn’t be a major obstacle.

The latest entrant in the universal TPMS sensor derby is the VDO REDI-Sensor from Continental. The VDO REDI-Sensor does not need to be programmed and does not require an electronic relearn tool in every instance. For example, when used on Chrysler vehicles it is self-learning, just like the original equipment replacement sensor, so the technician does not have to perform any additional steps. The differences do not stop there. Technicians can definitely speed up the process by using the hunt mode on a relearn tool to wake up the sensor, but in some cases, all the technician has to do is replace the sensor and then perform the relearn procedure for that particular vehicle. Only available as a clamp-in metal valve stem sensor, it is a two-piece assembly, so the valve stem can be replaced without scrapping the perfectly good electronics inside the sensor.

As it stands today, Continental says it can cover 90% of GM, Ford and Chrysler with two sensors it has, and with two more sensors next year (total of four) they will be able to cover 90% of all domestic and foreign models. They may need to release additional sensors down the road, but Continental indicated that the current REDI-Sensor is programmed to accommodate future makes and models scheduled for production over the next few years.

Both approaches have positives and negatives, but the bottom line is that retailers can significantly reduce the TPMS sensor inventory and actually gain coverage. It seems too good to be true, but it actually looks like sensor replacement will become much easier in the future. But don’t get too excited about the possibility of this carrying over to the original equipment level, because I’m guessing that the programmable/universal capabilities of these sensors makes them more expensive to produce. Therefore, I seriously doubt that the car companies will make life easier by spending extra money on high-tech sensors to help out the tire guys.

That’s probably because they’ll be allocating additional resources to make the electronics associated with TPMS more secure thanks to a study by Rutgers University and the University of South Carolina. “Though the study concedes that the potential for danger is very small, it also points to the inherent vulnerability in secure software development for new automobiles,” said Wenyuan Xu, a computer science assistant professor at the University of South Carolina.

Basically, a bunch of computer geeks (and I mean that in a sincere way; I love “The Big Bang Theory” on TV) got together and hacked the unencrypted RF signals from the TPMS sensors to cause the TPMS telltale to falsely illuminate. According to a report in Industry Week, the paper goes on to say that, “If the sensor IDs were captured at roadside tracking points and stored in databases, third parties could infer or prove that the driver has visited potentially sensitive locations such as medical clinics, political meetings, or nightclubs.” Thankfully, the technical people at Schrader were willing to provide a response to this study, and here is what they told MTD:

MTD: Can someone “forge” a TPMS sensor and “fool” a vehicle system in thinking it has a low tire?

Schrader: Technically this is possible, however, it is difficult, and certainly not as easy as the researchers suggest. First, it would require a significant amount of time, expensive equipment and know-how to receive and replicate a proper protocol. Next, the forger would have to stay within 25 to 30 feet of the vehicle for “extended periods of time” to cause the warning light to illuminate to the point of creating a false sense of security.

MTD: Can someone use the TPMS ID to track a driver’s location?

Schrader: This is not only impractical but nearly impossible. TPMS sensor transmitters are low signal devices subject to FCC Part 15 and are a Class C device. It is true that the signal is unencrypted, but due to the low signal strength, it would be highly unlikely anyone could read the signal from 130 feet away. It would be even more difficult to successfully read the signal when the vehicle is moving past a fixed location. The complexity in the market not only makes it difficult for this scenario, but also impractical. Even the author admits this: “Xu said that while it is possible to track someone by their tire IDs, the feasibility of doing so would be quite low. Someone would have to invest money by putting receivers at different locations,” she said. “Also, multiple manufacturers have different types of sensors, requiring different receivers. Each receiver in this test cost $1,500.”

Now that we can all sleep better at night knowing a TPMS telltale on the dashboard isn’t the result of nerd mischief, and a roving band of TPMS hackers cannot possibly track our every move and report it to “the man,” it’s still safe to say that TPMS is getting better. Even at the OE level, more areas of standardization are starting to appear. With the introduction of the EZ-Sensor and the VDO REDI-Sensor, it seems like the problem of inventorying replacement sensors appears to be solved. And if the manufacturers continue their efforts to educate the motoring public on the advantages and benefits of TPMS, it should get easier for retailers to sell the service packs and sensors.

We still have a long way to go as an industry, but I’m finally confident that tire dealers are starting to embrace the additional revenue possibilities by selling the benefits of maintenance.

We still have a long way to go as an industry, but I’m finally confident that tire dealers are starting to embrace the additional revenue possibilities by selling the benefits of maintenance.

We’re nowhere near the point where people are going to walk into the showroom and say, “I think I need some new TPMS sensors on my vehicle,” but we’re getting closer. And if the industry can continue to educate motorists on the benefits of maintaining the system, then it could end up being a good thing for everyone.

Kevin Rohlwing is senior vice president of training for the Tire Industry Association.

About the Author

Bob Ulrich

Bob Ulrich was named Modern Tire Dealer editor in August 2000 and retired in January 2020. He joined the magazine in 1985 as assistant editor, and had been responsible for gathering statistical information for MTD's "Facts Issue" since 1993. He won numerous awards for editorial and feature writing, including five gold medals from the International Automotive Media Association. Bob earned a B.A. in English literature from Ohio Northern University and has a law degree from the University of Akron.