Oh ! This is the part your going to Love about GM . You have to replace the complete tail light ! And here is the real kick to the groin , Its $750. and about an hour to replace . Or you could have the Stealership replace for $1200.
Why would you need to replace the complete tail light? Are you saying that the bulb is embedded into the LED unit? If that was the case and it was me, I would find a way to mount a new lamp inside the unit. The LED units cost a small fortune.
I have the exact same issue with my 2008 srx. Can you fill me in on how you fixed this issue? I figured out that my taillight was actually good. It seems to be either a fuse, wiring, or a faulty module. I have the entire car pulled apart so any help from a fellow SRX buddy is greatly appreciated.
I vaguely recall a discussion where tail light issues was traced to a broken wire in the transition from the liftgate to the body. A bunch of wires go thru the accordion tubes that you'll see at the top of the liftgate. Over time the flex from opening and closing causes a wire to break. You might try flexing the tubes to see if the faulty lights come on. I had this happen on a GMC Envoy. Fix was a matter of soldering the wires back together. May not solve your problem but cheap to try.