I have a 2008 STS. The rear passenger door can not be opened from the outside. I can open from the inside. Will not unlock using remote or driver control.
I have searched the forum and You Tube for how to test and replace a rear door lock module on my model Caddy...
Lots of info on CTS , Nothing I can find on STS other than it ain't like the STS.
I would greatly appreciate instructions on removing the lock module.
Testing the existiing module
The part number for the module
Installing lock module
A good supplier for this part.

and if that ain't enough tonight the "Service Air Bag" alarm popped up

Please help before anything else happens.

 

Check loose connection under passenger seat. Separate and reconnect, make sure latches are secure.