Lincoln 2015 MKZ Owner's Manual page 201

Parking Aids
The system does not offer a particular space
Something may be contacting the front bumper or side sensors.
There is not enough room on both sides of the vehicle in order to park.
There is not enough space for the parking maneuver on the opposite side of the parking space.
The vehicle is going faster than 22 mph (35 km/h).
The vehicle is farther than 4.9 ft (1.5 m) from the parking space.
The vehicle is closer than 15.75 in (40 cm) from neighboring parked vehicles.
The transmission is in reverse (R), the vehicle must be moving forward to detect a parking space.
The system does not position the vehicle where I want in the space
The vehicle is rolling in the opposite direction of the transmission (for example, rolling forward when you select reverse [R]).
An irregular curb along the parking space prevents the system from aligning the vehicle properly.
Vehicles or objects bordering the space may not be in the correct position.
You drove the vehicle too far past the parking space. The system performs best when you drive the same distance past the parking space.
The tires may not be installed or maintained correctly (for example, not inflated correctly, improper size, or of different sizes).
A repair or alteration has changed detection capabilities.
I n f o r ma t i o n P r o v i d e d b y :
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