Additional Service When Removing Battery Negative Terminal: Description
WARNING: This page is about a different car, the 2011 Nissan Leaf. However, it is still accessible from the selected car via links, so may be relevant.
Disconnecting the 12V battery negative terminal with the parking brake on, prevents the parking brake from releasing. To release, remove the cap on release hole in luggage floor, press and rotate counterclockwise the emergency release cable until it locks.