Tire pressure monitors

How this technology works

Tire pressure monitors check the air pressure of all the wheels and alert the driver when a tire's pressure has dropped below a safe level.

Two types of systems are currently in use:

  • One uses ABS sensors to measure the rotational speeds of the wheels. An under-inflated tire will have a slightly higher rotational speed
  • The second directly measures the pressure with a wheel mounted pressure sensor in each wheel


The system is on when the engine is turned on.


The driver is alerted by means of the tire pressure monitor light on the dash that the tire pressure has dropped below a safe level.

Things for drivers to keep in mind

  • Make sure you understand the tire pressure monitoring system installed in your vehicle
  • Some tire pressure monitoring systems provide a warning only when a tire is significantly underinflated. The tire may then be close to failure
  • When a monitoring system warns that pressure is low, measure your tire pressure and inflate to the appropriate pressure
  • Large temperature changes outside can cause the low tire pressure warning to come on
  • A warning message that the system is malfunctioning will also come on if the tires are changed or the tires are rotated and the system is not reset
  • When installing winter tires, be aware that the system may not work properly unless the correct type of pressure sensors for your vehicle are also installed
  • If buying new rims, make sure the pressure sensors fit on the rims
  • Newer tire pressure monitoring systems allow the driver to reset them
  • Tire pressure monitoring systems do not replace the maintenance procedures recommended in the owner's manual
  • You should continue to measure your tire pressure on a monthly basis
  • You should read your owner's manual to learn about your vehicle's system, including its capabilities and limits

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