The problem is solved.
Solution: While the liftgate was pushed to the down position (but not closed). I grabbed the power release latch above the license plate and held it for 5-10 seconds. It beeped during that time.
I then tapped it again briefly as I would normally to open the lid. Voila — the engine engaged and opened. Then I pressed the shut off button over my head inside the bottom of the hood and the engine shut it off, as it should.
I shut off the car and the hood closed for the first time all week. No more warnings about opening the door.
(Tip: Before doing this, first remove the spider web of bungee cords stretched across the back of the car to keep the gate closed.)
I came across this solution elsewhere on the forum and online after I started searching for “backgate” instead of switch or backdoor as I originally did before creating this thread. Turns out there were a few others who reported me before Correctly problem.
As best as I can tell, the engine shut itself off the other day because it felt resistance while in motion or because I accidentally tripped or because a piece of ice slipped on the roofline hinge.
Since it stopped working I have gotten a constant distant beep from the rear while driving, the key has been unlocked 24 hours a day and on a short trip the gate lifted about a foot while driving. The dome and hatch lights will stay on — while driving — but by design turn themselves off 20 minutes after the car is parked. Oh, and the white LED courtesy lights on the mirrors were shining in my eyes during the night drive, like I’d just pulled up to the car.
I had fixed an app. at my dealership tomorrow morning which I can now cancel. That would have involved almost half a day of driving/service time, so I’m happy to avoid that waste.
The service manager — and one at another dealership that couldn’t get to me until next week — suggested disconnecting the negative battery terminal to reset the port. (The second also suggested disconnecting the positive, then touching the two together to discharge the capacitor, which apparently holds the 1.21 gigawatts that make time travel possible.)
I wasn’t even able to do that, as a crescent wrench wouldn’t reach the battery terminal nut, and all three socket sets I owned lacked the magic 10mm socket it apparently requires.
Elsewhere, people said they just started carrying such a plug to disconnect the battery on the road in case of such a case. However, I take the position that topping up the wiper fluid is the only thing under the hood that an owner should reasonably be expected to do. It’s like waiting for someone’s grandmother with a laptop problem to loosen 15 hex screws in 4 sizes and disconnect the power supply to reset the computer. Unreasonable.
I love the ride I get in my 3-month-old 2021 Outback, but I’m appalled that I had to waste several hours of research and troubleshooting time to fix yet another weird thing with over-features. (Oh, and in response to another answer, I read the f’ing manual, as IT users will; I had previously stripped it down to learn about the machine. And I searched the entire PDF by keyword searching for the rear The solution was not there, nor is it well known in service departments, where the recipe seems to be to unplug and restart the car.
Shut the shutters thinking that this is what is expected of modern vehicle owners and that I am doomed for the next decade with this or any other vehicle I may have chosen.
At least now I can go back to scratching my head over the low mpg Outback that would cause concern for a Hummer owner.
