Ford 1999 Crown Victoria Owner's Manual page 123

TRANSMISSION OPERATION
Brake-shift interlock
This vehicle is equipped with a brake-shift interlock feature that prevents
the gearshift from being moved from P (Park) unless the brake pedal is
depressed.
If you cannot move the gearshift out of P (Park) with the brake pedal
depressed:
1. Apply the parking brake, turn ignition key to LOCK, then remove the
key.
2. Insert the key and turn it to OFF. Apply the brake pedal and shift to N
(Neutral).
3. Start the vehicle.
If it is necessary to use the above procedure to move the gearshift, it is
possible that a fuse has blown or the vehicle's brakelamps are not
operating properly. Refer to Fuses and relays in the Roadside
emergencies chapter.
Do not drive your vehicle until you verify that the brakelamps
are working.
If your vehicle gets stuck in mud or snow it may be rocked out by
shifting from forward and reverse gears, stopping between shifts, in a
steady pattern. Press lightly on the accelerator in each gear.
Do not rock the vehicle for more than a few minutes. The
transmission and tires may be damaged or the engine may
overheat.
Always set the parking brake fully and make sure the gearshift is
latched in P (Park). Turn off the ignition whenever you leave
your vehicle.
If the parking brake is fully released, but the brake warning lamp
remains illuminated, the brakes may not be working properly.
See your dealer or a qualified service technician.
Driving
123