If the motor to the automatic lift gate isn't working, most likely it your lock actuator. The auto lift gate mechanism is over $300. Some make the mistake in replacing the lift gate mechanism. Lock actuator is 50 to $100.

How do you keep yours open because mine will close fast

I wish this would solve my problem. Issue started with the button on the back not working, then the actuator would lock up while it was open. Replaced it, and still can't get it to open by button or keypad. I have to get inside just to unlock it to pop it open myself. Still trying to figure it out...