This is a link into my album with all the pictures re the repair of the upper hatch release latch located in the lower portion of the rear hatch.

DISCO3.CO.UK Photo Gallery - Liftgate release mod

 

I have the same issue. I tried holding lock/unlock buttons and I can hear the trigger sound but it still does not open. I am assuming it is a cable broken. I will take this thing apart but i am still hesitant of the fix. Thanks for all providing this info. I will keep you updated and will take some pics and post when it is all said and done.
2006 HSE LR3 - 107k and counting.

 

I fooled myself a couple of years back and also guessed that the cable L had broken when the real problem was the gear motor that sucks the cable back was growing weak. Note it is a gear motor and not a solenoid as I had also thought it might be.

With the engine running, the voltage at the rear going to the motor is closer to 14 volts than 12 volts and can give the motor the extra strength to pull on the cable and hence release the upper hatch door. With the engine off, all you get is clicking as the gear motor tries to pull the cable but is not strong enough due to the weaker voltage.

If you find the upper hatch door does release with the engine running, then the cable L is probably OK and the problem is the gear motor located inside the metal box is failing. The gear motor is the black flat sort of bit in the jpg below. The Land Rover part number is FUG500010.

Looking for updated ideas for solving lift gate and CEL problems

 

So this just went on mine, tried the reset nogo, started the engine and i was able to mess with the button enough to get it open once apart it was obvious the solonoids weak so left it apart till a new one comes, adding this to the tech section, i will also be adding an emergency release cable

 

New genuine rover latch solonoid and the glass works again

I did notice new one is 2016 dated and the plunger moves very easy and smooth , old one was much harder to compress

Thanks lucky8

 

I had to crawl into the back & open my 06 LR3 up a few months back. I was able to remove the tailgate flap, then pry back the carpet to gain access to the internals. It's not a fun job but it is something you can tackle vs having the dealership do it. I replaced the latch and the cable does seem to be made out of something different at the tip vs the OEM one that appeared to be pot metal. I didn't replace the solenoid as I tested it and mine was still very smooth and fast.