From the 2012 Terrain Owner's manual:
Symbols
The RVC system may have a feature that lets the driver view
symbols on the radio screen while using the RVC. The Ultrasonic Rear
Park Assist (URPA) system must not be disabled to use the caution
symbols. The error message Rear Parking Assist Symbols Unavailable
may display if URPA has been disabled and the symbols have
been turned on. See Ultrasonic Parking Assist on page 9‑46.
The symbols appear and may cover an object when viewing the radio
screen when an object is detected by the URPA system.
To turn the symbols on or off:
1. Shift into P (Park).
2. Press the CONFIG button.
3. Select Display.
4. Select Rear Camera Options.
5. Select Symbols. When a
check mark appears next to
the Symbols option, symbols
will appear.
This makes it sound as if symbols is only available on the SLT-2.
Guidelines
The RVC system has a guideline overlay that can help the driver align
the vehicle when backing into a parking spot.
To turn the guidelines on or off:
1. Shift into P (Park).
2. Press the CONFIG button.
3. Select Display.
4. Select Rear Camera Options.
5. Select Guidelines. When a
check mark appears next to the
Guidelines option, guidelines will
appear.