All American-made automobiles must have direct or indirect TPMS systems fitted as of 2008 as a result of the TREAD Act’s 2007 mandate.
Depending on the year, the Audi A4 (S4 8E B6, S4 8E B7, and S4 8K B7) is produced with a direct or indirect TPMS system. In the event that one or more tires on a Direct TPMS vehicle show low tire pressure, the TPMS sensors will communicate this information to the car’s ECU. Each tire pressure or an indicator light (low-line TPMS system) will be displayed on the dashboard (high-line TPMS system). The indirect TPMS system measures wheel speed through the ABS system rather than using TPMS sensors in the wheels.
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How does the TPMS system on an Audi work?
Direct TPMS: A sensor mounted on each wheel monitors the pressure in each tire, and it alerts you via the dashboard light if the pressure falls below 25%.
Audi employs either direct or indirect TPMS.
A rule developed by the National Highway Traffic Safety Administration is known as FMVSS 138. (NHTSA). The purpose of this law is to warn drivers if a tire’s pressure drops by 25%. A tire pressure monitoring device is needed for all vehicles made after September 2007. (TPMS). In Europe, where there isn’t an FMVSS 138 in force, drivers often check their tire pressure every two to three months, as Dr. Thomas Roscher, development engineer, Tire Pressure Monitoring Systems, Product Quality Assurance, Audi of America, notes. Let’s just say that the frequency isn’t that high in the US.
Early on during the development of the rule, it was believed that there would be two methodsdirect and indirectfor achieving the essential TPMS functionality. Actually, the standard is technology-neutral. It is important to complete the task, not to specify how it should be done.
Urban Forssell, president and chief executive officer of Linkoeping, Sweden-based NIRA Dynamics AB (www.niradynamics.se), claims that the first generation of indirect systems, of which only a few were in production, “shared a pairwise comparison of wheel speed. You compare the situation while assuming that only one tire at a time loses air.” He says, “If all four tires lost air simultaneously, you wouldn’t notice it.”
In light of the fact that FMVSS 138 additionally mandates pressure drop detection on all four tires, indirect TPMS generation one was insufficient. Because of this, all automakers have chosen the direct TPMS, which is a simpler solution. This means that there are pressure sensors installed within each tire, and that information is transmitted to a processor, which, if necessary, activates the warning. Although this method undoubtedly satisfies the standards, Roscher admits that unless there are certain adjustments, drivers essentially don’t care whether their TPMS system is indirect or direct. The driver might decide, for instance, that he wishes to switch from summer to winter tires. Or perhaps the motorist wishes to get a set of upgraded wheels. Alternately, the sensors’ batteries may run out. The customer will incur additional costs as a result of everything. As required by regulation, the tire dealer and the customer must both be certain that the TPMS system functions as intended after any changes. As such, there would be additional costs in addition to the price of new sensors for the new tires or wheels (e.g., this may necessitate a calibration phase during which time the vehicle would need to be driven, and undoubtedly hourly rates would apply).
Audi chooses to take the detour. Correct, an indirect TPMS. The generation 1 approach didn’t work, but NIRA Dynamics, which wasn’t involved in that technology, has developed a software-based system that, according to Forssell, has sufficiently strong algorithms to handle the NHTSA requirement of detecting 25% of tire pressure loss within 20 minutes while driving at a speed of 31 to 62 mph; the detection time is typically much faster than the NHTSA’s 20-minute requirement. Wheel-mounted battery-powered sensors are not present. neither radio transmitters nor receivers. Instead, the NIRA Dynamics system, called TPI (for “Tire Pressure Indicator”), uses the wheel speed sensors that are a part of the electronic stability control system (ESC) and antilock braking system (ABS) (ESC). In addition, a processor is required.
Wheel speed sensors have existed since the invention of ABS and have shown themselves as mature, stable, and dependable, according to Forssell. They serve as the NIRA Dynamics software’s input. The CPU that will first perform the calculations is a standalone unit. For instance, there will be what Roscher refers to as a “small gray box” for the 2009 Audi A6. The processor is there. It will eventually be included into the ESC processor, he claims. Moving forward, all that is required is to accommodate the controller’s indirect TPMS system.
The NIRA Dynamics TPI technology essentially “learns” the radii and frequency features of properly inflated tires. Then, it is capable of identifying any deviations from the standard that would occur from the loss of tire pressure (e.g., when a tire loses pressure, there is a change in the radius as the tire rotates, which has a consequent effect on the measured parameters). Any or all of the tires’ changes can be detected by the system (remember that the previous indirect systems measured pairs of tires unlike this one, which has inputs from each of the tires).
According to Roscher, this method is less expensive and simpler because it doesn’t require any extra sensors. The driver and/or tire dealer only need to recalibrate the system when wheels or tires are changed because this is a software-based system, the speaker continues, which is advantageous for customers (this essentially consists of selecting a reset function, then driving the car with properly inflated tiresperiod). “You can replace, even supersize, your tires, and the system will learn about them,” Forssell continues.
Forssell claims that Audi is the first automaker to make use of this indirect TPMS system as standard. By the 2011 model year, it’s predicted that the system would be standard on the whole Audi lineup.
Which TPMS brand does Audi employ?
Audi original sensors are compatible with all ATEQ tools. Numerous tools are available to configure universal aftermarket sensors for installation in Audi automobiles. Use any ATEQ TPMS tool, like the ATEQ VT36 or ATEQ VT56, to reset or relearn the Audi TPMS ECU. In the case of Auto Relearn, driving an automobile is necessary.
All TPMS-enabled automobiles in Europe as well as imported American vehicles are covered by the all-inclusive ATEQ VT56 TPMS tool. It includes all passenger car brands owned by the Audi and Volkswagen groups in addition to all other vehicles with TPMS available on the market. The tool serves as a complete diagnostic tool for all TPMS maintenance thanks to its OBDII module and sophisticated capabilities. Click here to learn more about the ATEQ VT56.
All Audi vehicles are supported by the TPMS activation and programming tool known as ATEQ VT36. The VT36 can be used in conjunction with a diagnostic scan tool to relearn the TPMS, or the user manual relearn procedures can be followed. On this page, you can learn more about the VT36 TPMS tool.
ARE AUDI VEHICLES EQUIPPED WITH DIRECT OR INDIRECT TPMS SYSTEMS?
In Audi passenger automobiles, tire pressure monitoring systems come in two main varieties: The first kind, known as indirect TPMS, relies solely on the ABS system and doesn’t employ any additional sensors. The low pressure warning is triggered if the wheel sensors notice that the diameter of one wheel is lower than the other and infer that the tire has lost air. The second kind, known as DIRECT TPMS, employs wireless TPMS sensors to monitor the air and temperature in the wheels directly and then transmits the information to the car’s computer. The direct sensors have the benefit of being more accurate. Depending on usage, TPMS sensors have a battery life of approximately 69 years. Determining whether a car has DIRECT or INDIRECT TPMS is difficult. Utilize a device like the VT56 from ATEQ. Each car model and year is clearly identified by the tool as having the appropriate TPMS system. Even for the indirect TPMS systems, the ATEQ VT56 offers detailed instructions for resetting the device.
HOW TO PERFORM AN INDIRECT TPMS RELEARN PROCEDURE ON A AUDI?
Many of Audi’s automobiles employ indirect TPMS. This fundamental mechanism determines whether there is a pressure problem or a puncture by using wheel rotation monitoring and frequently ABS wheel speed sensor information. Every time one or more tyre pressures are changed and after one or more wheels are replaced, the system needs to be reinitialized. The procedure differs from Audi car to Audi vehicle. Professionals can utilize an ATEQ VT56 TPMS tool to determine the relearn processes for all Audi vehicles, including the INDIRECT, fast. For all direct or indirect TPMS equipped automobiles, it includes detailed instructions.
HOW TO RESET THE TIRE PRESSURE LIGHT ON A AUDI WITH INDIRECT TPMS?
Make sure the tires on your Audi car are inflated to the correct pressure before anything else. Turn the ignition to the “On position without starting the vehicle. Release the TPMS reset button after holding it down while waiting for the light to blink three times. To reset the sensor, start the Audi vehicle and let it run for 20 minutes. Under the steering wheel is typically where you’ll locate the reset button for the tire pressure monitor. If you can’t find it, check your vehicle’s owner’s manual or refer to the thorough relearn instructions on the ATEQ VT56 tool.
How does a TPMS sensor identify the correct tire?
The anti-lock brake system’s wheel speed sensors are often used by an indirect TPMS. On-board computer systems can employ these sensors to compare wheel revolution rates between individual wheels as well as to other vehicle operation data, such as speed.
The computer can determine the relative size of the tires on your car based on how quickly each wheel rotates. The computer determines that a tire is underinflated when a wheel starts spinning more quickly than normal and warns the driver accordingly.
Therefore, a device for monitoring tire pressure indirectly does not truly measure tire pressure. The same kind of measurement you may observe with a tire gauge is not being processed electronically. An indirect tire pressure monitor only counts the rotational speed of your tires and sends instructions to the computer to activate the indication light when something seems off with the rotation.
How are the TPMS sensors powered?
The pressurized pocket created by a wheel and tire contains a small, programmable electrical device called a tire-pressure sensor that continuously checks the tire’s air pressure. The sensor uses low-frequency radio to send that data to the car’s onboard computer and, if it has one, a corresponding instrument cluster display. If one or more tires are low on air, it will glow an amber warning light and display the pressure in pounds per square inch (psi).
The so-called Tire Pressure Monitoring System depends on tire-pressure sensors (TPMS). Since becoming required in the US for the 2008 model year, millions of these devices have been installed in passenger vehicles. Batteries power the tire-pressure sensors, which are typically mounted to each tire’s valve-stem assembly.
How do TPMS sensors talk to one another?
Direct TPMS is susceptible to interference because it uses radio signal technology. A low frequency (LF) signal is used to activate the vast majority of TPMS sensors (125 KHz). This LF signal compels the sensor to communicate and varies from car to vehicle (some need more power than others). The TPMS sensors then use a UHF signal to communicate and transmit information (314.9-433.92 MHz).
As a result, there could occasionally be interference caused by anything transmitting in this range or by something like metal that would block a radio signal. However, interference is often uncommon and necessitates that the interference source be nearby and steady for a while.
There have been allegations of wireless transmitters in a store causing sporadic issues as well as metallic window film interfering with systems. Another case of interference was an improperly grounded electric motor that prevented surrounding TPMS sensors from turning on. Interfering signals may also be produced by microwaves, CRT computer monitors, and time card readers, though these are obviously uncommon.
Just be aware that moving the vehicle outside (or maybe another foot or two if the caliper is the source of the interference) will typically be enough to clear things up if there is interference, especially inside.
Honda issued a service bulletin in 2010 titled “Keep Your Distance When Doing Sensor ID Learning” that that a distance of 10 feet be maintained between any nearby TPMS sensors and the TPMS sensors being relearned.
The TPMS sensors will learn from one or more of them instead of the one that needs it if they are too close to one another. If this occurs, the low tire pressure indication will continue to flash even after the vehicle reaches a speed of more than 28 mph.
What determines if a TPMS is direct or indirect?
It is a direct system if your car has a tpms sensor within the tire. The indirect or direct system should be stated in your vehicle’s manual.
What is TPMS for Audi Direct?
Since 2002, Audi has kept up with TPMS advancements. To comply with the most recent law, they began by installing the optional system on the A8 and S8, and then they added it to the entire line. Numerous valve sensors have been employed. The fundamental function of the direct TPMS is to wirelessly transmit tire pressure to the driver via a sensor in the wheel or tire. Some cars have a digital data screen that continuously displays the pressures of all four tires (or five if the spare has a sensor). Others might only have a dash-mounted low tire pressure light that flashes. A valve sensor and a strap/band sensor are two more types of sensors for this system. The Audi with a direct system just uses valve sensors, however if you purchased an aftermarket SmarTire TPM system, it uses sensors attached by a strap around the wheel’s barrel.
You can find out if there is a system fault or if the tire pressure is too low using the tire pressure indicator in the instrument cluster. If the tire pressure in one or more tires is too low, the tire has structural damage, the tire pressure was changed, the wheels were rotated, or the tires were replaced but the TPMS was not reset, these characteristics may change and result in a tire pressure alert. An indirect tire pressure monitoring system (TPMS) measures the vibration properties and tire tread circumference of each tire. A warning symbol is displayed in the instrument cluster if the pressure drops in one or more tires.
It is virtually hard to avoid tire pressure monitoring systems (TPMS) when purchasing a new car. A TPM system is included as standard equipment in every new car built for sale in the USA. A few restrictions do apply, however, including the need that the vehicle have just four wheels (i.e., no motorbikes or dual-wheeled trucks) and that the GVWR be under 10,000 lbs.
At TPMS DIRECT, we make every effort to ensure appropriate fitting. We keep all parts in stock for all makes and models of Audis and purchase in bulk from the supplier to ensure availability and the lowest rates.