Tire Pressure Monitoring System
If your vehicle has this feature, it is designed to alert you when the system detects a large change in the pressures on one tire. The system cannot alert you before you drive that a tire is low or flat. You must begin driving before the system will work properly. The system works with the brake control system and is designed to detect differences in the tire rotation speeds that are caused by changes in tire pressure. The tire pressures monitoring system does not replace normal tire maintenance.
The light, on the instrument panel cluster,
comes on when the tire pressure monitoring
system detects a low-tire condition.
This light will also come on for a few seconds and then go off when you turn the ignition on. This indicates that the tire pressure monitoring system is functioning properly. If the low tire pressure warning light comes on while driving tour vehicle, the system may have detected a low tire condition. You need to stop as soon as possible and check your tires for damage. Also check the tire pressure in all four tires, and set them to the specified level shown on the tire and loading label.
The tire pressure monitoring system on you vehicle will warn you when one of your tires is significantly under inflated and when some combinations of your tires are significantly under inflated. However, there are other combinations of significantly under inflated tire for which your tire pressure monitoring system may not warn you. These other combinations are relatively common, accounting for approximately half the instances in which vehicles have significantly under inflated tires. For example, your system may not warn you when both tires on the same side or on the same axle of your vehicle are significantly under inflated. It is particularly important, therefore, for you to check the tire pressure in all of your tires regularly and maintain proper pressure.
A drop on tire pressure could be the result from:
* A puncture caused by a nail or other foreign object
* A poor seal between tire & wheel
* The need for routine tire maintenance
* Changes in ambient temperature
HOW TPMS WORKS
The wheels' air-pressure sensor/transmitter assemblies transmit individual air-pressure levels via radio signal to the receiver/control unit. Roll switches in the assemblies turn on the sensors when vehicle speed reaches between seven and 20 mph.
Transmitter data include detected air-pressure, ID code and a code indicating the transmitter's current mode. Each assembly's sensor takes measurements every 30 seconds, which are transmitted every 60 seconds. After the vehicle has stopped for 15 minutes, the sensors enter sleep mode to conserve their batteries. They have life expectancies of 10 years or 1000,000 miles.
The receiver/control unit collects data from the sensor/transmitter assemblies via built-in antenna. If air pressure drops between 26 and 27 psi in one or more tires, the unit illuminates the warning light in the instrument panel, the system design does not indicate which tire is low.
By warning of a tire's air pressure loss, TPMS helps drivers avoid accidents. An added benefit is the reduced wear and tire to a vehicle's power train and chassis, potentially improving durability and lowering the cost of ownership.
