Rear latch opens while driving - 2007 Hyundai Accent GS Hatchback

it sounds as if the locking latch on the rear panel has been distorted with the heavy load, smother the lock on the trunk with grease and gently lower down and see where the grease leaves a mark , this way you can see where the latch on the rear panel should be , both the lock on the trunk and the latch on the rear panel have some adjustment so you will have to adjust both until they line up again

use a round bar ( a screw driver ) and place it under the latch and pull the latch out as you press the button to unlock as if you were opening the door.

try to spray like WD40 to release.

the latch in the left rear door is either bad or stuck, open door, then with a screwdriver, rock latches in door to simulate closed. release with exterior handle. spray lubricant (WD40) into latches and continue to exercise the latch. if this quick fix does not work, then a new latch for this door may be needed.

DW Mylin

This fix is for 2011 rear manual door.
You may experience some light turns on while driving over a bump or take a sharp turn. Your rear hatch indicator said door is opened.
The courtesy switch is located inside the rear hatch latch assembly. Nothing more but a simple thin lever line leave spring that contacts the ground pole to tell body ECU the door is opened.
The spring is so thin that it bent out of shape overtime therefore when you close the door it doesn't get pushed away from the ground pole far enough caused intermittently false door open alarm.
ALl you have to do is to remove the door latch assembly. Separate the actuator from the latch. Look into the latch you would see a copper like spring one end rests onto the ground pole. Jam your screw driver between the latch housing and spring lightly pride it away from the pole to unbend it. . Manually close the latch and look to see if it gets pushed away from the pole. If it doesn't try to unbend it again.
If you have or know how to use a ohm meter than check for continuity between spring and it housing. You should get 0.3-1.0. Ohm when the latch is open and no continuity when you closed the latch.
Any question shoot me a email constant12vdc@yahoo
ED

Looks like dirt, moisture and others have combined to clog the linkage mechanisms of your lock/latch.
You would need a can of lubricant such as WD-40. Spray the lubricant on the lock/latch, and try to close the door. Repeat as necessary and watch what happens.
Once the latch begins to operate, dab some clean engine oil to the latch again, this wiould ensure long-life trouble-free operation.

If the door won't open from either the inside or outside than there is a problem with the latch assembly or alignment. You can use the other rear door to see how the child lock works. Meanwhile, you'll have to remove the door panel on the right rear door from inside the vehicle. Then you can reach inside with a screwdriver and flashlight and work the latch free. Once you get it open you can further diagnose if it is alignment or a faulty latch assembly. It's not going to be easy getting the door panel off from inside or working the latch to release. I hope this helps.

Section 501-14A: Handles, Locks, Latches and Mechanisms 1997 F-150, F-250 Workshop Manual REMOVAL AND INSTALLATION Latch, Rear Door — Upper Removal

1. Remove the rear door trim panel; refer to Section 501-05 .

1. Remove the rear door radio speaker.
   1. Remove the four radio speaker screws.
   1. Disconnect the electrical connector.
   1. Remove the rear door radio speaker.

1. Carefully peel off the rear door watershield.

1. Disconnect the upper rear door latch cable.
   1. Lift the clip.
   1. Pull to release the cable from its seated position.

1. Remove the upper rear door latch.
   1. Remove the three screws.
   1. Pull the upper rear door latch and the cable up through the door latch opening.

use small box wrench and remove the catch attached to the window. insert 2 washers over each of the 2 connecting bolts ..4 washers required min 2 per side. re attach window catch. This should move the catch forward ehough to depress the locking mechanism.... it worked perfect on my 02 Liberty.

The easy part is you just need the latch for the liftgate. The hard part is getting to it and opening the liftgate to replace the latch. You should be able to pull the liftgate trim off most of the way with the gate closed and try to manually actuate the latch to open the gate. You may have to go so far as breaking the latch from the inside to open the gate and then replace your latch.