Honda RDX Owner's Manual page 132

Tailgate
Unlocking the Tailgate
COVER
If the power door lock system cannot
unlock the tailgate, unlock it
manually.
Use a small flat-tip screwdriver to
remove the cover on the back of the
tailgate.
126
LEVER
Push and hold the release lever to
the right as shown, then push the
tailgate to open it.
If you need to unlock the tailgate
manually, it means there is a
problem with the tailgate. Have the
vehicle checked by your dealer.