TPMS: It’s The Law

TPMS: It’s The Law

Maintaining proper tire pressure is essential for safety and fuel economy.

Tires lose air pressure over time. Even new tires lose up to 10% of their pressure in a year. Punctures and corrosion from aluminum wheels and bad valve stems all contribute to tires running at underinflated pressures. Recognizing the danger of driving on underinflated tires, the U.S. Congress passed the TREAD Act in 2000, mandating tire-pressure monitoring systems (TPMS) in all passenger cars and light trucks sold as of Sept. 1, 2007.

TPMS sensors are physical-pressure transducers that are part of the valve stem mounted inside the tire, or in some cases, strapped inside the wheel. Tiny radio antennas fixed inside the units send unique IDs and tire-pressure data to the powertrain control module (PCM). A specialized scan tool is required to check the sensor and read the ID code and then program it into the PCM.

The TPMS scan tool can turn off the warning light and find fault codes associated with the system, which can be triggered by battery failure, a broken sensor/valve, replacement of wheels and sensors for custom wheels, tire rotation or installation of winter tires.

Typically, direct TPMS sensors will last between five to 10 years. Some TPMS sensors only become activated when the tire is rotating to help conserve the battery life, but the more a vehicle is driven, the closer to the end of the battery (and transmitter) life it may be. After a set of tires has worn out, inspect the TPMS before installing a new set.

Damage to the sensor can occur to sealing components whenever a wheel is removed. Selling TPMS service kits is an excellent way to help customers maintain proper air pressure and keep the sensors in working order. Tires are regularly exposed to elements such as road salt in the winter that can cause galvanic corrosion around the stem. These symptoms can cause small air leaks. But some OE replacement sensors have the valve stem permanently attached to the sensor body and cannot be replaced.

If you’re selling replacement sensors, keep in mind a sensor must be reprogrammed for the specific vehicle before it can be installed in the tire. The sensor also needs to go through a relearn process – a step some techs miss.

Aftermarket sensors often require special programming to meet the vehicle’s specifications before installation and relearn. These may include TPMS sensors that are labeled “programmable,” “universal” or “cloneable.” A special TPMS scan tool is required to check the sensor and read the ID code and then program it into the PCM. The scan tool will find fault codes associated with the system and will shut off the warning light.

Maintaining proper tire pressure is essential for safety and fuel economy, and it also helps the tires wear in an even pattern so they’ll last longer. Keeping a supply of TPMS service parts and replacement sensors on hand will give your customers peace of mind knowing that they’ll be alerted to any tire issue before there’s a catastrophic failure, which is why they’re mandatory.

You May Also Like

MAF and MAP Sensors

These small-but-mighty components play an outsized role in keeping fuel-injected engines running smoothly.

MAF and MAP Sensors

While it might not sound like it to the untrained ear, the orchestration of components to achieve the ideal combustion cycle is nothing short of a symphony.

For fuel-injected engines, two important instruments in this precise arrangement are the mass airflow (MAF) sensor and the manifold absolute-pressure (MAP) sensor.

Electronic Parking Brakes

Safety, convenience and holding power – what’s not to love?

Electronic Parking Brake
Driveshaft Dynamics

Don’t let the terminology trip you up.

Driveshaft
Serpentine Belts Have a Strong Supporting Cast

Tensioners, balancers and pulleys are working behind the scenes to maintain harmony under the hood.

Tensioners and Pulleys
Artificial Intelligence in the Automotive Aftermarket

The applications for AI are endless, but hurdles still remain.

AI Aftermarket

Other Posts

SMP Introduces 208 New Part Numbers in January

The release provides new coverage in 72 product categories and 115 part numbers for 2022, 2023 and 2024 model-year vehicles.

SMP January
Interpreting Dashboard Warning Lights

Navigating the neon jungle isn’t as easy as it used to be.

Dashboard Diagnostics
Stopping Power: Brake Master Cylinders

The brake master cylinder is the hydraulic hero behind every safe stop.

Brake Master Cylinder
Active vs. Passive Wheel-Speed Sensors

Both have the same job, but they differ in how they do it.