Quantcast
Jump to content
  • Welcome to Auto Parts Forum

    Whether you are a veteran automotive parts guru or just someone looking for some quick auto parts advice, register today and start a new topic in our forum. Registration is free and you can even sign up with social network platforms such as Facebook, Twitter, Google, and LinkedIn. 

     

APF

Indirect Tire-Pressure Monitoring System: The ‘Other’ TPMS

Recommended Posts

Indirect TPMS

It’s been more than a decade since the federal government first mandated that new vehicles feature tire-pressure monitoring systems to warn drivers against underinflation. Direct TPMS sensors and their service kits are a common stocking item for parts stores, tire shops and even general repair shops nationwide, but while these sensors are now well-known and widely available, there is another system that provides tire-pressure monitoring without sensor service and replacement.

In the case of direct TPMS, radio frequency signals from each tire-mounted sensor are transmitted to a central receiver, where the individual air-pressure readings are compared to the manufacturer’s recommended inflation pressure. If the actual pressure in any tire drops below 75 percent of this recommended calibration, the warning light will illuminate. Some manufacturers also display the actual pressure of each tire in their driver information center (usually found in the gauge cluster) during startup.

Indirect TPMS, as its name implies, does not use a direct “PSI” reference to calculate tire pressure. Instead, this system estimates any pressure differentials based on vehicle and wheel speed, as well as tire size. Indirect TPMS piggybacks on the ABS and traction-control system, using the information from these sensors to determine if an individual tire is underinflated. The theory behind indirect TPMS is that the circumference of a tire decreases slightly as it deflates, and the rolling resistance of the tire increases. By using individual wheel-speed sensor information, the system can detect the difference between an underinflated tire and a properly inflated tire. Onboard software can calculate just how much difference exists between wheels, and based on the manufacturer’s recommended tire size, make a determination on the percentage of underinflation, and trigger the warning light at the same 75 percent threshold.

It is a cost-effective system for manufacturers, with no additional hardware in terms of sensors and receivers. It can represent a long-term savings to consumers who otherwise would periodically replace battery-operated sensors and service kits, and for drivers who have multiple sets of tires for their vehicle. Many Northern drivers maintain a full set of “winter wheels” with snow tires, rather than dismounting tires each season. Sports car enthusiasts may also maintain a set of “track wheels” for weekend racing, with some sanctioning bodies requiring functional TPMS as part of their safety inspection. Finally, any “tire buster” tasked with mounting and dismounting tires at the local tire shop can tell you that with indirect TPMS, it’s a relief not to have to worry about breaking off a sensor during tire service.

Indirect Tire-Pressure Monitoring System

Of course, indirect TPMS has limitations, as seen in the first crop of indirect TPMS-equipped vehicles in the late 1990s and early 2000s. These systems could only sense if a single wheel was underinflated, as it compared the individual tires to each other. If all four tires were uniformly underinflated, all four speed sensors would have the same values. No warning would be given, even if the tires were severely low. These systems also required a four-channel, four-wheel anti-lock brake system to operate, which was not widely used with light trucks or rear-wheel-drive passenger cars at the time.

Indirect TPMS also requires recalibration any time tire pressures are adjusted, or when tires are rotated or replaced. These systems also may give false warnings in wet or icy conditions, as the rotation of slipping or spinning tires will differ when they break traction. It also relies on all of the monitored tires being the same size, with accuracy being compromised when larger- or smaller-than-stock tires are fitted to the vehicle. Finally, indirect systems cannot function while the vehicle is stationary, leaving the driver unaware of a potential problem until after the vehicle is already in motion.

While older systems also lacked the ability to identify which tire was underinflated, advancements in wheel-speed sensor technology have made this an available feature on many newer vehicles equipped with indirect TPMS. They are considerably more accurate than previous designs and can be found on several modern import nameplates, including various Audi, Honda, Mazda and Toyota models.

Although indirect TPMS is a less expensive option for the manufacturers, and it does have a simplicity of design, direct TPMS is still a more widely used and accurate system, with the added benefit of requiring us to provide a steady supply of replacement parts to our customer base.

Source: 

link hidden, please login to view

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Similar Topics

    • By Auto News
      link hidden, please login to viewSummer is the main season for “cone zones,” road construction where you will likely hit a bump or two, or come across loose stones and other hazards. These rough road conditions can be tough on a vehicle’s steering and suspension system and can throw out the alignment, while loose stones have the potential to damage the vehicle’s exterior or windshield, according to the non-profit Car Care Council. “Even the most careful motorist, who is driving slowly and carefully through road construction, is bound to hit an unexpected bump or other road hazards,” said Nathan Perrine, executive director, Car Care Council. “Be sure to pay attention to your car and if you think there’s a problem, have it taken care of as soon as possible.”
      The main symptoms of steering and suspension or wheel alignment problems are uneven tire wear, pulling to one side, noise and vibration while cornering or loss of control. The council recommends that motorists have their vehicles checked out immediately if any of these symptoms exist, as steering and suspension systems are key safety-related components and largely determine the car’s ride and handling. Regardless of road conditions, these systems should be checked annually and a wheel alignment should be performed at the same time.
      Motorists also should do frequent visual checks of their vehicle’s exterior and windshield to identify any chips, dings or cracks. These are small problems that can become costly repairs and safety hazards if they aren’t taken care of immediately.
      For information to help you keep your vehicle running dependably and protect its long-term value, visit the Car Care Council’s website at 
      link hidden, please login to view and sign up for the link hidden, please login to view. The non-profit Car Care Council is the source of information for the “Be Car Care Aware” consumer education campaign promoting the benefits of regular vehicle care, maintenance and repair to consumers. For the latest car care news, visit the council’s online media room at
      link hidden, please login to view. To order a free copy of the popular Car Care Guide, visit the council’s consumer education website at link hidden, please login to view. The post
      link hidden, please login to view appeared first on link hidden, please login to view.
      link hidden, please login to view
    • By Auto News
      link hidden, please login to viewSummer is the main season for “cone zones,” road construction where you will likely hit a bump or two, or come across loose stones and other hazards. These rough road conditions can be tough on a vehicle’s steering and suspension system and can throw out the alignment, while loose stones have the potential to damage the vehicle’s exterior or windshield, according to the non-profit Car Care Council. “Even the most careful motorist, who is driving slowly and carefully through road construction, is bound to hit an unexpected bump or other road hazards,” said Nathan Perrine, executive director, Car Care Council. “Be sure to pay attention to your car and if you think there’s a problem, have it taken care of as soon as possible.”
      The main symptoms of steering and suspension or wheel alignment problems are uneven tire wear, pulling to one side, noise and vibration while cornering or loss of control. The council recommends that motorists have their vehicles checked out immediately if any of these symptoms exist, as steering and suspension systems are key safety-related components and largely determine the car’s ride and handling. Regardless of road conditions, these systems should be checked annually and a wheel alignment should be performed at the same time.
      Motorists also should do frequent visual checks of their vehicle’s exterior and windshield to identify any chips, dings or cracks. These are small problems that can become costly repairs and safety hazards if they aren’t taken care of immediately.
      For information to help you keep your vehicle running dependably and protect its long-term value, visit the Car Care Council’s website at 
      link hidden, please login to view and sign up for the link hidden, please login to view. The non-profit Car Care Council is the source of information for the “Be Car Care Aware” consumer education campaign promoting the benefits of regular vehicle care, maintenance and repair to consumers. For the latest car care news, visit the council’s online media room at
      link hidden, please login to view. To order a free copy of the popular Car Care Guide, visit the council’s consumer education website at link hidden, please login to view. The post
      link hidden, please login to view appeared first on link hidden, please login to view.
      link hidden, please login to view
    • By Auto News
      Summer is the main season for “cone zones,” road construction where you will likely hit a bump or two, or come across loose stones and other hazards. These rough road conditions can be tough on a vehicle’s steering and suspension system and can throw out the alignment, while loose stones have the potential to damage the vehicle’s exterior or windshield, according to the non-profit Car Care Council.
      “Even the most careful motorist, who is driving slowly and carefully through road construction, is bound to hit an unexpected bump or other road hazards,” said Nathan Perrine, executive director, Car Care Council. “Be sure to pay attention to your car and if you think there’s a problem, have it taken care of as soon as possible.”
      The main symptoms of steering and suspension or wheel alignment problems are uneven tire wear, pulling to one side, noise and vibration while cornering or loss of control. The council recommends that motorists have their vehicles checked out immediately if any of these symptoms exist, as steering and suspension systems are key safety-related components and largely determine the car’s ride and handling. Regardless of road conditions, these systems should be checked annually and a wheel alignment should be performed at the same time.
      Motorists also should do frequent visual checks of their vehicle’s exterior and windshield to identify any chips, dings or cracks. These are small problems that can become costly repairs and safety hazards if they aren’t taken care of immediately.
      For information to help you keep your vehicle running dependably and protect its long-term value, visit the Car Care Council’s website at 
      link hidden, please login to view and sign up for the free custom service schedule. The non-profit Car Care Council is the source of information for the “Be Car Care Aware” consumer education campaign promoting the benefits of regular vehicle care, maintenance and repair to consumers. For the latest car care news, visit the council’s online media room at 
      link hidden, please login to view. To order a free copy of the popular Car Care Guide, visit the council’s consumer education website at link hidden, please login to view. The post
      link hidden, please login to view appeared first on link hidden, please login to view.
      link hidden, please login to view
    • By CarPartAU
      Complete Conversion for a HSV VF LSA
      Date Listed:27/03/2020 Last Edited:27/03/2020 Make:Holden Special Vehicles Warranty:yes Condition:used Visit us @ link hidden, please login to view
  • Our picks

    • Advance Auto Parts To Sponsor NASCAR Weekly Series In Multiyear Agreement
      DAYTONA BEACH, Fla. & RALEIGH, N.C.--(BUSINESS WIRE)--As NASCAR Weekly Series sanctioned events begin to return at select tracks across North America, NASCAR and Advance Auto Parts (NYSE: AAP), a leading automotive aftermarket parts provider, today announced a multiyear official partnership, designating Advance as the series entitlement sponsor. As part of the agreement, Advance also becomes the “Official Auto Parts Retailer of NASCAR.”

      "It's great to have Advance join us in welcoming the return of NASCAR-sanctioned grassroots racing," said Ben Kennedy, vice president, racing development, NASCAR. "Advance’s commitment to our Weekly Series will develop some of the brightest NASCAR talent across North America. Advance has a long history in racing, and we’re thrilled to see its expanded presence from the grassroots all the way through our national series.”
      • 0 replies
    • Advance Auto Parts Announces Purchase of the DieHard Brand from Transformco
      Advance Auto Parts, Inc. (NYSE: AAP) has acquired the DieHard brand from Transform Holdco LLC (“Transformco”), for $200 million utilizing cash on hand.

      “We are excited to acquire global ownership of an iconic American brand. DieHard will help differentiate Advance, drive increased DIY customer traffic and build a unique value proposition for our Professional customers and Independent Carquest partners. DieHard has the highest brand awareness and regard of any automotive battery brand in North America and will enable Advance to build a leadership position within the critical battery category,” said Tom Greco, president and CEO, Advance Auto Parts. “DieHard stands for durability and reliability and we will strengthen and leverage the brand in other battery categories, such as marine and recreational vehicles. We also see opportunities to extend DieHard in other automotive categories. We remain committed to providing our customers with high-quality products and excellent service. The addition of DieHard to our industry leading assortment of national brands, OE parts and owned brands will enable us to differentiate Advance and drive significant long-term shareholder value.”
      • 0 replies
    • AmazonBasics 6-Pack High Mileage Motor Oil - Synthetic Blend
      AmazonBasics High Mileage Motor Oil - Synthetic Blend

      AmazonBasics high-mileage synthetic-blend motor oil offers an enhanced level of protection for engines over 75,000 miles. Its synthetic blend combines conventional oil with synthetic for cost efficiency with some of the benefits of a full synthetic. An important part of routine maintenance, the motor oil works well for anything from topping off levels to complete oil changes. Whether it’s a beloved older vehicle or one with an uncertain maintenance history, help protect its engine with AmazonBasics high-mileage, synthetic-blend motor oil.
      • 3 replies
    • OEM vs. Aftermarket Parts for Your Car: How to Choose
      When selecting parts for a car repair, it pays to know the differences between original and aftermarket parts. Whenever possible, get estimates for both.

      Choosing between original and aftermarket car parts — and even used parts of either type — is all about squaring your priorities with your budget.

      You’ll have different options depending on the part and the shop. And the best choice will depend on whether you’re trying to keep repairs cheap, restore your car’s appearance after a wreck or soup up your ride.

      Original equipment manufacturer (OEM) parts match those that came with your car, and are of the same quality as its original parts. They’re also the most expensive.
        • Like
      • 1 reply
    • Replacement Intervals For Oil And Air Filters In Today’s Vehicles
      The factory-recommended replacement intervals for filters can vary quite a bit depending on the year, make and model of the vehicle, as well as how it is driven. As a rule, older vehicles (those more than 15 to 20 years old) typically have more frequent service intervals than newer vehicles. Why? Because late-model vehicles require less maintenance, thanks to improvements in motor oils, transmission fluids, engine design and filter media.

      Many long-life air and oil filters use synthetic fiber media or a blend of cellulose and synthetic fibers to extend filter life.

      Changing the oil and filter every 3,000 miles was standard practice decades ago. But it’s no longer necessary because most multi-viscosity oils today are a synthetic blend or a full synthetic that resist viscosity breakdown and oxidation for a much longer period of time. Late-model fuel-injected engines also run much cleaner than their carbureted ancestors, which reduces oil contamination in the crankcase.
        • Like
      • 0 replies
×
×
  • Create New...

Copyright © 2020 AutoPartsForum Powered by Invision Community