Chevrolet 2010 Colorado Owner's Manual page 11

Power Door Locks
Press L or U on the switch on the armrest to lock or
unlock the doors.
For more information see:
Door Locks on page 3 7
Power Door Locks on page 3 8
Tailgate
Open the tailgate by pulling up on the outside handle
while pulling the tailgate down.
On vehicles with a locking tailgate, use the ignition key
to unlock it.
For more information see Tailgate on page 3 10.
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