Press lock to lock all doors. Press unlock once to unlock the driver's door. Press twice to unlock all doors. In the summer you may want to hold down the unlock button. This will open the windows to allow the vehicle to cool off before you enter.
Press and hold the power liftgate button. This will open or close the liftgate.
The panic button can be used to locate the vehicle by pressing once. The lights will flash and the horn will chirp. In an emergency you can sound the alarm by holding down the panic button for 2 seconds. Press again to end the alarm.
To use remote start press the lock button then press and hold the remote start button. If you want your climate controls to perform particular tasks (like heating the seats and blowing heat in the winter, or the opposite in the summer) set your climate control defaults in the vehicle personalization menu. Instructions can be found in the owner's manual.
Order remotes for your Cadillac SRX here: http://www.remotesandkeys.com/searchresults.asp?cat=3744