Honda Civic Service Manual: Battery System

Electrical

...

Battery Removal and Installation

Removal 1. Battery Terminal - Disconnection 1. Make sure the ignition switch is in LOCK (0). ...

See also:

Honda Civic Owners Manual. Driver Information Interface Warning and Information Messages*
The following messages appear only on the driver information interface. Press the  (display/information) button to see the message again with the system message indicator on. Message Condition Explanation Appears if any door or the trunk is not completely clos ...