NAPA AUTOPRO

Know Your Tire Pressure Monitoring System (TPMS)

Checking a vehicle’s tire pressure monitoring system (TPMS) is as easy as getting into the car and turning the ignition on. If the TPMS indicator light turns off, the system is functioning properly and you can be on your way. If it remains on or starts flashing, there may be an issue.

SOLID LIGHT – If the light stays on, check to see if the tires are properly inflated or if there’s damage.

FLASHING LIGHT – There is a system failure and very likely a bad sensor. Further TPMS diagnostics will need to be completed.

How TPMS sensors communicate

TPMS sensors wirelessly transmit a protocol specific to the vehicle and a unique ID serial number that identifies the tire location. Replacement sensors must match the original protocol, and the vehicle needs to learn each new sensor’s ID. This typically requires a relearn process.

What can cause TPMS sensor failure?

  • Collisions, potholes, curbs, and other road hazards
  • Sensor battery failure: sensor batteries are not serviceable or replaceable, so they will eventually discharge and fail (lifespan of approximately 7–10 years or over 160,900 kilometres)

What can trigger a TPMS light?

  • Any tire that is 25% over- or underinflated
  • Rotation of the tires without resetting the TPMS
  • TPMS sensor failure in one or more tires

What are the risks of ignoring the TPMS light?

  • Poor fuel efficiency and shorter tire life
  • Compromised vehicle handling
  • Diminished braking performance

TPMS sensors require service

The valve stem, seal, washer, nut, valve core, and cap in a TPMS sensor are intended for one-time use. Just like your wiper blades, certain parts of a TPMS sensor are made of rubber and break down over time. Failure to replace these parts can lead to slow tire leaks or catastrophic tire failure. Industry-leading professionals, including the TIA and OE vehicle manufacturers, recommend replacing the TPMS sensor every time a tire is removed from its wheel.

How auto-relearn technology works

Auto-relearn automatically identifies each TPMS sensor, determines its position on the vehicle, and then wirelessly transmits the information to the receiver for display on the dash—all without human intervention. Below are two popular auto-relearn technologies.

Phase angle location (PAL) technology

Phase angle location uses additional ABS data along with TPMS sensor data to transmit tire pressure, temperature, position, and directional rotation while the vehicle is being driven. Vehicles equipped with PAL systems utilize the data to accurately identify the TPMS sensors’ location and pressure, which is displayed on the driver display.

Wireless auto-locate (WAL) technology

Wireless auto-locate systems use advanced TPMS technology and RF signal strength to determine sensor location following tire rotation or the installation of a new sensor.