Hmmmmm.......some testing will be necessary. You'll need to determine if the compartment cover motor is getting power or not. It's easy to check, no tools required! The motor is located above the headliner, all the way in the rear, right in the center. Try this. Open the tailgate completely. Move the tailgate latch to the locked position (use a screwdriver), and wait until it locks. Then, place your hand up against the headliner in the area of the motor. Operate the tailgate handle with your other hand so that the latch pops open. If you feel a distinct movement from the area of the motor, it's getting power. If it's not getting power, you've probably got a problem with the rear SAM. If it is getting power, the cover could be stuck. If it's stuck, try removing the guide rails and re-installing them, tension-free.