Honda Civic Owner's Manual page 112

uuLocking and Unlocking the DoorsuLocking/Unlocking the Doors from the Outside
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Unlocking the doors
Press the unlock button.
Once:
u Some exterior lights flash twice, and the driver's door unlocks.
Twice:
u The remaining doors unlock.
* Not available on all models
110
*
1Using the Remote Transmitter
If the distance at which the remote transmitter works
varies, the battery is probably low.
If the LED does not come on when you press a
button, the battery is dead.
2 Replacing the Button Battery P. 401
You can customize the door unlock mode setting.
2 Customized Features P. 90