I took this right out of the manual. I think this is what you want to do.

Todeactivate/reactivate the autolock feature using the keypad Yourvehicle comes with the autolock feature activated. Todeactivate/reactivate thisfeature: 1.Electronicallyunlockthevehicle.
2.Turntheignitiontothe3(OFF)position.
3.Closeallthedoors,liftgateandcargodoors.
4.Enter the 5-digit entry code.
5.Press and hold the 7•8. While holding the 7•8, press and release the 3•4.
6.Releasethe 7•8. The horn will chirp once when the system has been successfully deactivated. The horn will chirp twice (oneshortandonelongchirp)when the system has been successfully reactivated. To deactivate/reactivate the autolock feature using the power door unlock control You must complete Steps1-7 within 30 seconds or the procedure will have to be repeated. If the procedure needs to be repeated, you must wait 30 seconds.
1.Insert the key and turn the ignition to the 4 (ON)position.
2.Press the power door unlock control three times.
3.Turn the ignition from the 4 (ON) position to the 3 (OFF)position.
4.Press the power door unlock control three times.
5.Turn the ignition back to the 4 (ON) position. The horn will chirp.