FORD 2003 Explorer v.1 - Manual (Page 252)

Do not replace your tires with “high performance” tires or larger
size tires.
Failure to follow these precautions, your vehicle handling may be
adversely effected which can lead to loss of vehicle control,
vehicle rollover and/or personal injury.
Tires that are larger or smaller than your vehicle’s original tires may
affect the accuracy of your speedometer.
Tire pressure monitoring system (TPMS) (if equipped)
The tire pressure monitoring system provides the driver with a warning
message indicating when tire pressure is severely low or high. This
system is a supplement to normal tire maintenance including regular
manual inspections. The device will inform the operator of severe low or
high inflation pressures, but may not illuminate for less severe
discrepancies in inflation pressure.
The system uses radio-frequency pressure sensors to monitor the tire
pressure on all tires including the spare. The sensors transmit the tire
pressure readings to the receiver module located in the vehicle. The
receiver module then transmits the status to the message center. For
more tire warning information, refer to the Message Center in the
Driver controls chapter.
This device complies with part 15 of the FCC rules and with RS-210 of
Industry Canada. Operation is subject to the following two conditions:
(1) This device may not cause harmful interference, and (2) This device
must accept any interference received, including interference that may
cause undesired operation.
The tire pressure monitoring system is NOT a substitute for
manually checking tire pressure. The tire pressure should be
checked periodically (at least monthly) using a tire gauge, see
Checking the tire pressure in this chapter. Failure to properly
maintain your tire pressure could increase the risk of tire failure, loss
of control, vehicle rollover and personal injury.
Maintenance and Specifications
252