Tire Pressure Monitor System - Chevrolet 2007 TrailBlazer Owner's Manua

If your vehicle has P255/50R20 104V size tires
installed on the rear axle, they will require
inflation pressure adjustment when driving your
vehicle at speeds above 99 mph (160 km/h).
Set the cold inflation pressure, for the rear tires
only, to the maximum inflation pressure shown on
the tire sidewall, or 38 psi (262 kPa), whichever
is lower. See the example following. When you end
this high-speed driving, return the tires to the
cold tire inflation pressure shown on the Tire and
Loading Information label. See Loading Your
Vehicle on page 356.
Example:
You will find the maximum load and inflation
pressure molded on the tire's sidewall, in small
letters, near the rim flange. It will read something
like this: Maximum load 690 kg (1521 lbs)
300 kPa (44 psi) Max. Press.
For this example, you would set the
inflation pressure for high-speed driving at
38 psi (262 kPa).
The inflation pressure for the front tires should be
set to the cold tire inflation pressure shown on
the Tire and Loading Information label.
Racing or other competitive driving may affect the
warranty coverage of your vehicle. See your
warranty booklet for more information.

Tire Pressure Monitor System

The Tire Pressure Monitor System (TPMS) uses
radio and sensor technology to check tire pressure
levels. TPMS sensors are mounted on each tire
and wheel assembly, except the spare tire.
The TPMS sensors monitor the air pressure in
your vehicle's tires and transmit tire pressure
readings to a receiver located in the vehicle.
The TPMS is designed to alert the driver if a low
tire pressure condition exists. If your vehicle
has the Driver Information Center (DIC) steering
wheel control buttons, tire pressure levels
may also be checked through the DIC. See "Tire
Pressures" under DIC Operation and Displays
on page 221.
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