Whether an open hatch drains the battery depends on the vehicle's design, its condition, and how long the hatch stays open. There's no single setting that solves this across every make and model. Here's what to actually do before you're standing at the tailgate lot with a cooler in one hand and a carabiner in the other:

• Check your owner's manual for a cargo mode, liftgate setting, or interior-light timeout specific to your vehicle. Some vehicles have one; plenty don't.
• Don't defeat the latch with a carabiner, wedge, or any other workaround unless the manufacturer explicitly documents that exact procedure for your vehicle. Nothing in the research for this article shows a manufacturer endorsing this hack.
• If the manual offers no approved method for extended hatch-open use, treat that as your answer: keep the hatch open only while someone's around to notice a problem, or get the current draw tested by a shop before leaving it open for hours unattended.
• A manual-approved configuration explains how the feature is supposed to work. It doesn't guarantee low battery draw on its own, especially over several hours.

A carabiner jammed into the latch changes what one sensor reports. It doesn't necessarily change what the rest of the system is doing. In the Forester case, the dashboard displayed "locked" after the trick, and the battery still drained overnight (SubaruForester.org).

The thread doesn't pin down exactly which circuit caused the draw, which is exactly why that result shouldn't be treated as gospel for every vehicle running a similar hack. What it does support is a broader point: power liftgates aren't single-sensor systems. They're built from separate switches, sensors, motors, and control modules, and a technician can use a scan tool to isolate which one is misbehaving (CarParts.com, more than two years ago). A trick that spoofs one sensor reading has no way of accounting for what else in that system is still pulling current.

Multiple posts in the same thread describe this as a known issue on some 2019 and early-2020 Foresters, tied to the power rear-gate (PRG) module. Owners say it mainly shows up when the hatch sits open for extended stretches rather than during a quick loading job (SubaruForester.org).

One participant said the relevant service bulletin was issued in July 2019 and revised three times since, most recently in February 2021. That same owner had the earliest fix, tied to PRG module revision J004, installed on their 2019 Forester under warranty, and it didn't stop the draw. Revision J006 was reportedly the first update to address what the bulletin calls "dark current," but a further revision, J007, followed, suggesting the fix wasn't complete even then (SubaruForester.org).

Outcomes varied by owner. One dealer replaced the module under warranty using the earlier revision, and it didn't help. Another owner had the module replaced in 2021 and said they'd since left the rear hatch open constantly for tailgating and camping with no further issues (SubaruForester.org). Same underlying issue, different results, and the thread never explains why the revision alone accounts for the gap.

One owner also mentioned the repair had been classified as a customer satisfaction recall, which might mean a dealer would cover the work outside the standard warranty window. That's the owner's own reading of the situation, not confirmed policy, so anyone in that spot should check eligibility directly with the dealer or Subaru rather than lean on a forum post.

None of this is verified against Subaru's internal service records; it's owner testimony on a public forum. Taken together, though, it's a reasonable warning that even a manufacturer's repeated attempts at a fix didn't land the same way for every owner.

Liftgate systems vary enough between brands that a workaround suited to one vehicle can be irrelevant, or actively risky, on another. Buick's AutoSense Power Liftgate, for example, only operates with the vehicle in park, and it mutes the key fob if the fob lingers within 10 feet of the liftgate for more than two minutes (Buick). That's a set of conditions specific to that platform and useless as a guide for anything else.

Your owner's manual documents how your own system operates, something a borrowed forum trick from a different make, model, or year simply can't account for. On the 2019 Forester, the manual describes a manual latch release for the rear hatch on page 429, a detail one forum participant flagged specifically so other owners wouldn't resort to cutting the latch mechanism open (SubaruForester.org). Many vehicles include some kind of manual emergency release for a power liftgate, but the location and procedure are model-specific (CarParts.com). Follow the manual rather than prying into the trim panel on your own guesswork.

If the hatch has already caused an unexplained dead battery, or your vehicle turns out to share a known issue like the Forester's, stop testing workarounds and get it looked at. The path from there is straightforward:

• Before the trip: confirm your owner's manual has no approved extended-hatch-open setting. If it doesn't, plan to keep the vehicle attended or get the draw tested in advance.
• After one unexplained dead battery: don't repeat the setup hoping for a different outcome. Book a diagnostic appointment before the next trip.
• At the shop: bring the VIN and a plain description of the symptom, something like "battery drains when the hatch is left open overnight," rather than naming a specific part or bulletin yourself.

An OBD scan tool connected to the liftgate module can point a technician toward the likely fault and where to look next (CarParts.com). The Forester bulletin history is a good argument for letting the shop drive that process: owners reported multiple revisions with different outcomes, so having a technician check the current bulletin against your VIN beats guessing which fix applies (SubaruForester.org).

For a genuine stopgap while waiting on a repair, one Forester owner disconnected the battery entirely between trips, but was clear he didn't want that to become a permanent routine (SubaruForester.org). It's a reasonable short-term measure, not a fix, and disconnecting a battery can reset other vehicle settings in the process.

The carabiner trick spread because it sounds plausible: fool the sensor, save the battery. What the Forester case shows is that the sensor was never the whole system in the first place. Skip the workaround, read the manual for your specific vehicle, and if a dead battery has already happened once, get the VIN and symptom in front of a technician before the next tailgate rather than after.