I had this same thing happen a few months ago. What is wrong is the release motor is just fine, but it releases the hatch by way of a little 2 inch plastic piece. On mine(and most likely yours), it snapped. So the motor and the emergency release are working fine, but the piece that connects to the latch is broken. It's a relatively easy fix that you can do on your own.
You'll have to buy the whole latch motor contraption, since they won't sell you the plastic piece alone. It's about $85, and the only place that sells it is a dealership. Unless you can find one at a scrap yard or something.
To keep from ripping apart the plastic on the tailgate to gain access, you'll need to get the window open. Do this by actually removing the handle that is fastened by 2 bolts in the inside of the window. You'll have pry the plastic back enough to gain just enough access to fit a wrench in there and back the nuts off till the handle on the outside comes off. This will allow the glass to swing up so you can flip the tailgate down and remove the plastic covering.
You'll see the plastic piece that is broken on the latch, I believe it's a bright blue or neon green 2-inch piece. It doesn't come off with any tools, just wiggle and work the latch till it comes of. Replace, reassemble, enjoy.
It may sound daunting, but actually quite easy when you get the idea. E-mail me if you have any further questions about this.
Jones. Scotty8@yahoo. Com
Sunday, January 16th, 2011 AT 3:11 PM