Ford Crown Victoria 2011 Owner's Manual page 279

Crown Victoria Severe Duty
4. Press and hold the brake pedal
for two seconds, then release.
5. Turn the ignition to off - DO
NOT remove the key.
6. Cycle the ignition from off to on three times ending in on - DO NOT
start the engine.
If the reset mode has been entered successfully, the horn will sound
once, and the TPMS indicator will flash.
If after repeated attempts to enter the reset mode, the horn does not
sound, and the TPMS indicator does not flash, seek service from
your authorized dealer.
279
2011 Crown Victoria (cro)
Owners Guide, 3rd Printing
USA (fus)