My wife's 2010 RX350 wouldn't start this morning. My guess is that the battery drIned overnight with the back door ajar. After getting it started with a battery jump the rear hatch would not open by hand, the dash button or the key button. After driving and charging the battery the hatch would open. I'd this to be expected or an indication that perhaps the hatch has a fault?

Thanks!

 

It's likely due to the fact that the battery didn't have enough power to engage the motorized opening of the liftgate. You have a button in the glove box to disable the power hatch to open up at least manually if the dead battery reoccurs.

If the battery has never been replaced, you are due since typical lifespan is 5 years and seeing you live in Minnesota (MN) you'll need a fresh battery to ensure reliable starting power over this winter.

 

I know this post is years old, but to help anyone who is searching for a solution to the tailgate problem after having a dead battery.
Forget the solutions using the switch at the glove box. Do however make sure it's in the correct position.
What I have found with every battery change (or dead battery) the tailgate needs to be reset. To do this:
Lock the car using the remote, wait about 30 seconds then unlock the car. Open the tailagte using the car button (not the fob) then close it after a few seconds.
This has fixed the open/close issue everytime for me.

 

this works for me! Thanks so much. We saw some other more complicated suggestions on the Internet that were ultimately unsuccessful and this was an easy, successful fix! Thank you.