8/3/2019 TPMSPaperRev1
1/1
Originator: Michael Blackmer Page 1 of 1 Date Issued:
9/5/2007
Document1 Date Revised: 9/24/2007
TIRE PRESSURE MONITORING SYSTEM
BackgroundBeginning with the 2008 model year, all Crown Victoria
Police Interceptors (CVPIs) are equipped with a TirePressure
Monitoring System (TPMS) that illuminates a low tire pressure
telltale (see Figure 1) on the instrumentcluster when one or more
of your tires is significantly under-inflated. Accordingly, when
the low tire pressuretelltale illuminates, you should stop and
check your tires as soon as possible, and inflate them to the
properpressure. Driving on a significantly under-inflated tire
causes the tire to overheat and can lead to tire
failure.Under-inflation also reduces fuel efficiency and tire tread
life, and may affect the vehicles handling andstopping ability.
Understanding the Tire Pressure Monitoring System (TPMS)
The TPMS measures pressure in your four road tires and sends the
tire pressure readings to your vehicle. The Low Tire
Pressuretelltale will turn ON if the tire pressure in one or more
tires is significantly low. Once the light is illuminated, your
tires are underinflated and need to be inflated to the
manufacturers recommended tire pressure. Even if the light turns ON
and a short time laterturns OFF, your tire pressure still needs to
be checked.
When inflating your tiresWhen putting air into your tires (such
as at a gas station or in your garage), the TPMS may not respond
immediately to the airadded to your tires. It may take up to two
minutes of driving over 20 mph (32 km/h) for the light to turn OFF
after you have filledyour tires to the recommended inflation
pressure.
How temperature affects your tire pressureThe TPMS monitors tire
pressure in each tire on the road. While driving in a normal
manner, a typical passenger tire inflationpressure may increase
approximately 2 to 4 psi (14 to 28 kPa) from a cold start
situation. If the vehicle is stationary over night withthe outside
temperature significantly lower than the daytime temperature, the
tire pressure may decrease approximately 3 psi (20.7kPa) for a drop
of 30 F (16.6C) in ambient temperature. This lower pressure value
may be detected by the TPMS as beingsignificantly lower than the
recommended inflation pressure and activate the TPMS warning for
low tire pressure. If the low tirepressure warning light is ON,
visually check each tire to verify that no tire is flat. (If one or
more tires are flat, repair as necessary.)Check air pressure in the
road tires. If any tire is under-inflated, carefully drive the
vehicle to the nearest location where air can beadded to the tires.
Inflate all the tires to the recommended inflation pressure.
Changing tires with TPMSEach road tire, as well as the spare, is
equipped with a tire pressure sensor fastened to the inside rim
ofthe wheel (see Figure 2). The pressure sensor is covered by the
tire and is not visible unless the tire isremoved. The pressure
sensor is located opposite (180 degrees) from the valve stem. Care
must be takenwhen changing the tire to avoid damaging the
sensor.
When your spare tire is installedWhen one of your road tires has
been replaced by the spare, the TPMS system will continue to
identify anissue to remind you that the damaged road wheel/tire
needs to be repaired and put back on the vehicle orthat the
installed spare needs to be "trained" to the vehicle. Note: Your
spare tire has a sensor installed onthe wheel, but the TPMS
receiver must be "trained" to receive it. The receiver can only
receive foursignals, and the signal from each transmitter is
digitally unique to avoid interference from transmitters onother
nearby vehicles.
Tire RotationThe TPMS sensors do not need to be retrained when
tires are rotated if the same four wheels are used.
TPMS System Training ToolsAn inexpensive TMPS training tool, P/N
8C2Z-1A203-A, can by purchased from any Ford dealer for use by
the driver or shop technician for training the system after
maintenance has been performed that requiressystem training. The
Tire Pressure Monitor Activation Tool, P/N 204-363, has more
functionality and is designed primarily for shopuse. For either
tool, follow the training instructions as outlined in the shop
manual.
How to tell when a wheel has a TPMS sensor insideAll CVPI wheels
since the 2006 model year have "Sensor may be inside" stamped on
the inside of the wheel since some of thewheel components are used
on other vehicle lines that incorporated TPMS before CVPIs did.
However, the wheel's build date, at
the end on the second line, is a good indicator of whether or
not a CVPI wheel has a sensor installed. As production of the
2008models began on May 7, 2007, a wheel build date of May 1 or
later will most likely have a sensor installed. Alternatively, the
TirePressure Monitor Activation Tool, P/N 204-363, can also be used
to determine if a sensor is present in a wheel as it
providesfeedback to the operator by flashing a green LED when a
sensor responds to the tool.
System MalfunctionWhen the system detects a malfunction, the
telltale will flash for approximately one minute and then remain
continuouslyilluminated. This sequence will continue upon
subsequent vehicle start-ups as long as the malfunction exists.
When the malfunctionindicator is illuminated, the system may not be
able to detect or signal low tire pressure as intended. TPMS
malfunctions may occurfor a variety of reasons, including the
installation of replacement or alternate tires or wheels on the
vehicle that prevent the TPMSfrom functioning properly. Always
check the TPMS malfunction telltale after replacing one or more
tires or wheels on your vehicle toensure that the replacement or
alternate tires and wheels allow the TPMS to continue to function
properly. Please refer to theOwner Guide for more details.
Figure 1. Low Tire
Pressure Telltale
Figure 2. TPMS Sensor
Location on Wheel
