If the keyless remote battery or the vehicle battery is dead, use the key instead of the keyless remote.
Fully insert the key and turn it.
Locking/Unlocking the Doors Using a Key
When you lock the driver’s door with a key, all the other doors lock at the same time. When unlocking, the driver’s door unlocks first. Turn the key a second time within a few seconds to unlock the remaining doors.
Models with driver information interface
You can customize the door unlock mode setting.
Customized Features
Honda Civic Service Manual. Front Door Glass Outer Weatherstrip Removal and Installation (4-door)
8241C8 LEFT
8241C9 RIGHT
Removal
1.
Front Door Power Window Switch Panel (4-door)
1.
Remove the power window switch panel (A).
...