Bob Weber is president of Virginia-based Write Stuff. He is an award-winning freelance automotive and technical writer and photographer with over two decades of journalism experience. He is an ASE-certified Master Automobile Technician, and has worked on automobiles, trucks and small engines. He is a member of the Society of Automotive Engineers (SAE) and numerous other automotive trade associations. He has worked as an auto service technician, a shop manager and a regional manager for an automotive service franchise operation.
Tire pressure monitoring systems (TPMS) are a significant advance in driving safety, but most motorists are unaware of the system’s importance or what to do when the warning light comes on.
You owe it to your customers to replace malfunctioning sensors, but it is not always an easy sell. Motorists generally detect no problems — no noises, no vibrations, no major drop in fuel economy, no bulging tires.
They may balk at paying for something that seems unnecessary and may even ask you to simply disable the light so that they may go on their way.
That is why it’s important to educate your customers on the benefits of replacing sensors. Once informed, the job may sell itself.
The Car Care Council reports 70% of the vehicles on American highways are being driven with one or more low tires.
A national survey commissioned by Schrader International Inc., a TPMS manufacturer, showed that:
- nearly one-half of drivers (46%) could not correctly identify what the TPMS icon symbolizes,
- one-third (32%) admit they don’t know what the icon represents; and
- one in 10 (10%) incorrectly identified it as some other warning.
The survey also found that, while nearly all drivers (96%) agree that driving a car with under-inflated tires is a safety issue, nearly half (44%) admit they rarely check their tire pressure.
The National Highway Traffic Safety Administration (NHTSA) estimates tire failure causes approximately 11,000 crashes a year. Under-inflated tires or worn-down treads are a major cause of failure.
NHTSA’s Crash Causation Survey found there was an issue with a tire before the crash occurred in nearly 10% of crashes (one in 11).
While driving, tires get hot from friction created as the tire constantly flexes. You can replicate the effect by repeatedly stretching a stout rubber band; it warms up quickly. Do this long enough and the rubber band may eventually break. Tire heat damage may lead to tread separation.
In the late 1990s, Ford Explorers had high failure rates of certain 15-inch Firestone tires leading to loss of control and vehicle rollovers which caused injuries and deaths. The U.S. Department of Transportation investigated the issue. That investigation resulted in the Transportation Recall Enhancement, Accountability, and Documentation (TREAD) Act, passed by Congress in 2000. Part of the TREAD Act requirements was a way to monitor drops in tire pressure. That gave birth to the tire pressure monitoring system. When the TPMS warning symbol appears, it means one or more tires are at least 25% lower than specified. In a tire that requires 35 psi, that represents about 9 psi low.
Beginning on Sept. 1, 2007, all light vehicles (excluding motorcycles and trucks with dual wheels) have been required to have tire pressure monitoring systems.
NHTSA estimates that when all passenger vehicles are equipped with TPMS, it will reduce the number of annual motor vehicle crash fatalities by about 120 and the number of injuries by about 8,500.
Many motorists don’t recognize the icon. It does not look like anything familiar. The temperature icon is a thermometer. The low fuel icon is a gas pump. The low tire pressure icon is a cross-section of a tire with an exclamation point in the center. Most consumers have never seen a cross-section of a tire.
Recently, on some vehicles, the driver information center (DIC) spells out a low pressure warning and many systems even report which tire is the culprit. And some have tire fill alerts (horn chirp and/or lights flash when tires are filled to the proper pressure).
Numerous states are also getting involved. For example, in 2010, the California Air Resources Board (CARB) implemented a mandatory pressure check on vehicles whenever any emissions service is done, and several states now include a properly functioning TPMS system as part of their periodic motor vehicle safety inspections.
Can you profit from TPMS service?
There has been some information from NHTSA about properly inflated tires increasing fuel economy and that TPMS sensors contribute to it. However, there is little proof to back up the claim that the system saves motorists money. Trying to sell customers on the money-saving prospect probably won’t land the job.
Writing in our sister publication, Modern Tire Dealer, Kevin Rohlwing, the Tire Industry Association’s (TIA) senior vice president of training, stated that safety is the key to selling the job.
Safety is still by far the most important benefit of TPMS, which means retailers must continue to focus on the role that proper tire inflation plays in the operation of the vehicle.
Sure, there are some additional benefits like reduced rolling resistance and a slight improvement in fuel economy. But the average consumer can quickly see that the return on investment is virtually impossible to realize when it comes to dollars and cents using the data contained in the NHTSA report.
While TPMS can potentially improve tire service life and tread wear, those particular benefits still depend on motorists who regularly rotate their tires, not to mention check and adjust the inflation pressure before the light is illuminated on the instrument panel.
Lazy consumers who spend hours looking for the remote control rather than getting up to change the channel are not going to put a gauge to every tire until it’s too late. TPMS gives them the warning they need that prompts them to pay attention to their tires before the pressure gets to the point where a tire failure is imminent.
The safety benefits of TPMS are immeasurable when lives hang in the balance, so that’s the message a motorist needs to hear.
TIA recently launched a quarterly consumer education program that revolves around the association’s new tagline, “Tire Safety Starts Here.”
In the first video, “Tire Safety Starts with Proper Tire Repair,” TIA shows motorists why tires should be removed from the rim before they are repaired. The second installment is titled “Tire Safety Starts with TPMS” and it is focused on the safety benefits related to this technology. There is a brief mention of the potential fuel savings and tread wear improvement, but the emphasis is on safety because that is the only concept that will convince most consumers to spend the money to maintain, repair and replace the TPMS on their vehicles.
Consumer education continues to be the missing link for TPMS because the general public is unaware of what it does, why it’s there, and how it can save the lives of motorists. And by failing to create value in the minds of vehicle owners, the industry is now faced with millions of vehicles that will soon require new sensors and millions of drivers that will only see dollars and cents when faced with the decision to maintain the system.
Progressive retailers who have embraced TPMS technology and taken the time to explain the benefits to their customers over the past few years are more likely to reap the rewards of a new revenue stream, while those who have complained and resisted should not expect to see any positive changes in sales.
But TPMS should never be about money or profit. It started as a national movement to improve safety on the highway and somewhere along the line the message was distorted and the motorist ignored. The industry has gone to great lengths to convince retailers that there was a pot of gold at the end of the TPMS rainbow.
TPMS service and the law
There is still one area of TPMS service that many auto service professionals are confused about.
It is the “make inoperative” words in the Federal Motor Vehicle Safety Act. Must auto service providers repair a faulty system before the vehicle can be returned to the customer?
According to the law, “A manufacturer, distributor, dealer, or motor vehicle repair business may not knowingly make inoperative any part of a device or element of design installed on or in a motor vehicle or motor vehicle equipment in compliance with an applicable motor vehicle safety standard prescribed under this chapter….”
What, exactly, does that mean to an auto service professional? When asked, a surprising number of techs think that the only illegal action is to purposely disable the TPMS. Many also believe that they may not legally release a car back to the customer if the warning light is on.
In a written letter to NHTSA, TIA asked for clarification on several key points.
TIA’s letter outlines four different TPMS scenarios that service professionals regularly face. Each scenario includes how the “make inoperative” provision of the Motor Vehicle Safety Act (49 USC 30122(b)) applies to each situation.
In the first scenario, TIA asked if a retailer can replace an inoperative TPMS valve stem sensor with a standard rubber snap-in valve stem and still comply with the “make inoperative” provision.
NHTSA’s response was that as long as the TPMS part was inoperative before the customer brings the vehicle to the repair business, “a motor vehicle repair business would not be violating 49 USC 30122(b) by removing an inoperative or damaged TPMS sensor and replacing it with a standard snap-in rubber valve stem.”
However, a repair business that goes on to make any other element of the TPMS inoperative, for example, by disabling the malfunction indicator lamp, would violate the “make inoperative” provision.
“This is exactly why our training programs have always stressed the importance of checking the status of the TPMS prior to service,” said Rohlwing. “If a valve stem sensor is not functioning prior to servicing the tires and wheels, then the retailer cannot violate the ‘make inoperative’ provision because the system was already inoperative. This increases the importance of documenting an inoperable TPMS prior to any work being performed on the vehicle, especially now that the batteries in the sensors are starting to die.”
The second scenario focused on the purchase of aftermarket winter tires and wheels and the customer’s refusal to purchase new TPMS sensors or pay for the labor to transfer the original sensors to the aftermarket wheels.
NHTSA responded that if the TPMS is functioning at the time of the aftermarket tire and wheel purchase, “a service provider would violate the ‘make inoperative’ prohibition of 49 USC 30122(b) by installing new tires and wheels that do not have a functioning TPMS system.
To avoid a “make inoperative” violation, the service provider “would need to decline to install the new tires and rims, use the TPMS sensors from the original wheels (if they are compatible), or convince the motorist to purchase new TPMS sensors and ensure that the sensors are properly integrated with the vehicle’s TPMS system.”
“We are admittedly surprised by NHTSA’s response that aftermarket tires and wheels must include TPMS sensors,” remarked Roy Littlefield, TIA executive vice president. “Based on the language in the April 2005 final rule, we believed that the presence of the malfunction indicator lamp (MIL) would notify the driver that the TPMS was not operable as a result of their decision to decline new sensors or pay for the additional labor to install the original sensors in the aftermarket tire and wheel assemblies. While we have some genuine concerns regarding consumer backlash, it is clear that the Federal government is requiring retailers to make sure the TPMS continues to function following the purchase of aftermarket tires and wheels.”
In the third scenario, TIA asked if a service provider violates the “make inoperative” provision if they inadvertently break a non-defective sensor and cannot locate an immediate replacement. TIA asked if it was a violation to allow the vehicle to return to service because arrangements were made to obtain and install the replacement part at a future date.
NHTSA’s response was, “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.”
The fourth and final scenario describes a situation where a vehicle is released to the consumer without an illuminated MIL and then it illuminates after the vehicle has been driven. 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.”
Of course, offering to repair the malfunction is the best solution.
Making sense of sensors
Estimates put the total number of TPMS sensors currently found in the U.S. at over 100 million. If your business does not offer TPMS service, it is missing business.
Many of the original TPMS sensors are reaching the end of their projected service life. The batteries, which are intended to last up to 10 years, are dying. The batteries are not replaceable.
There was a time that the only source for replacement sensors was the automobile dealer’s parts department. There was a wide range of designs and stocking all of them at an aftermarket shop would be insanely costly. Sending someone to fetch a replacement sensor, though unproductive, was the only option. This tied up an employee as well as inconvenienced the customer, particularly if they were in your waiting room.
Fortunately, the aftermarket has risen to the challenge and offers replacement sensors of all designs.
When it comes to selecting a replacement sensor, you have three basic choices:
- Direct replacement, or “part for part” replacement sensors, can be obtained from original equipment as well as aftermarket providers, and typically do not require any programming or configuring with a TPMS tool.
- Multi-protocol sensors, as the name suggests, come “pre-loaded” with many sensor protocols in a single sensor body. Again, no configuring is required, but a TPMS tool is needed to do the “re-learn.”
- Programmable sensors typically represent fewer SKUs, but are able to cover a greater range of vehicles. The sensors are blank or in need of configuration before use.
There are two basic types of sensors: One-piece and two-piece.
A one-piece sensor has the housing and valve molded together. The valve is not removable. The items that should be serviced on this style of sensor include the valve core, hex nut, grommet, cap and washer. If the valve is broken or corrosion has occurred, this sensor is not serviceable and the entire sensor will need to be replaced.
Two-piece: A two-piece sensor has a removable valve stem that can be separated from the sensor housing. The serviceable items on this style of sensor are a replacement valve, valve core, hex nut, grommet and cap. With this type we also have two different valve configurations.
OE manufacturers recommend replacing the two-piece, snap-in rubber valve whenever the sensor is removed from the wheel. The rubber snap-in valve is attached to the sensor module by a hex nut (or Torx screw).
When two-piece, clamp-in sensors are removed from a wheel, the sensor should be fitted with a new rubber grommet, aluminum retaining nut, special nickel-plated valve core and valve cap. It is important that all components be torqued to appropriate values to prevent air leaks and valve damage. Attempting to reuse the original rubber grommet, valve core and retaining nut may result in an air leak.
There are three types of sensor relearns: stationary, OBD and auto learn.
Stationary relearn sensors need an activation tool with the car in “relearn” mode. New IDs can be programmed without driving the vehicle.
OBD relearn requires an activation tool in conjunction with an OBD scan tool to program new sensor IDs into the vehicle. New IDs can be programmed without driving the vehicle.
With the auto learn sensor, the vehicle can learn a single new ID and in some cases multiple new IDs without the use of a tool. The vehicle must be driven a prescribed time in order to turn off the light.
Charting the way
You do not need to memorize the various relearn protocols. Each carmaker provides the necessary information. But there is a more convenient way: the TIA TPMS Relearn Chart.
The TPMS chart is divided into domestic and import vehicle sections and includes relearn requirements, relearn summaries, OEM sensor part number, and replacement sensor and seal kit part numbers for Schrader International, Dill Air Controls Products, Myers Tire Supply, 31 Inc. Xtra-Seal, Continental VDO and NAPA. It also includes the sensor numbers for Orange Electronics and Standard Motor Products.
The chart lists the torque specs for the sensor nut, Torx bolt, worm gear and vehicle wheel fasteners.
The 2015 TPMS Relearn Chart includes troubleshooting tips to help technicians when the relearn is not working, revised relearn summaries so that they are more easily understood, pictures and part numbers for common multi-app, programmable sensors on the market and a valve reference page with pictures and part numbers of the various type of TPMS valves.
“The TPMS Relearn Chart is a durable, easy-to-use source of information that is specifically designed to be handled and used by technicians on the shop floor. With the annual updates, technicians are always prepared to service whatever vehicle drives into their shop,” said TIA Director of Automotive Training Development Sean MacKinnon.
The bottom line
Granted, you won’t get rich (or even keep the lights on) by installing replacement kits that cost you about $5 and retail out at $10. Ditto for replacing complete sensors. But it may prevent a come-back that may take rather than make money. It also ensures customer satisfaction and that translates into repeat business.
Complete diagnostics and sensor replacements produce some parts and labor income.
Most important, customers learn from an informed service pro and willingly opt for TPMS sensor replacement. The customer profits from excellent service. You boost your bottom line a bit with professional TPMS service. ●