2022 Subaru Outback: battery drain or dead battery

Filed Sep 15, 2026 · Electrical · NY

In September 2026, after a jump start, my vehicle's battery emitted a strong sulfur/rotten-egg odor, indicating overheating and overcharging. I was advised to shut it off immediately. The vehicle is now undrivable and parked, and I am concerned it presents a fire risk. This is the latest failure of a chronic electrical defect documented in the dealer's own repair orders since early ownership: •⁠⁠March 16, 2023 (4,985 mi): vehicle needed a jump start. Dealer tested the battery, said it passed, and blamed my driving habits. •⁠⁠May 16, 2023 (5,503 mi): vehicle again needed a boost. Battery failed the dealer's test and was replaced under warranty; dealer cited Subaru bulletin 07-213-22R. •⁠⁠August 4-8, 2025 (15,188 mi): vehicle again needed a boost. Battery failed the dealer's DCA8000 test (low CCA) and was replaced a second time. A dark-current draw test found the Telematics Data Communication Module (DCM) causing a parasitic draw (code B2A0C); the DCM was replaced. When I arrived to collect the vehicle after being told it was repaired, it would not start in the dealer's own shop. Subaru paid for the DCM repair as one-time goodwill while stating it was not covered by warranty. These repair orders understate the frequency: throughout ownership the vehicle needed a jump start roughly 80-90% of the times I used it, even the day after being driven, and I used roadside assistance several times. I believe this matches the known parasitic battery drain defect on 2021-2022 Subaru vehicles (control modules, including the DCM, failing to enter low-power sleep mode), the subject of pending class action litigation (Taylor v. Subaru of America, No. 2:26-cv-4935) and Subaru technical service bulletins. My dealer replaced the implicated module, the problem recurred, and the vehicle has now had an overcharging event that left it undrivable.

Filed Jun 5, 2026 · Electrical, Transmission · AZ

Recently, the 2022 Outback my mom drives has been having some strange electrical issues. About a year-or-so ago the battery in her outback died. Not unusual in Arizona. I replaced it with an upgraded AGM (Interstate) version—same group, same cranking power. No issues. Recently, after an oil change at the dealer, she called back to report that a “Check Engine” light had come on. She was told that she probably had not put the gas cap on properly. Gas cap was on properly; light went off the next day. A few days later the Auto Stop/Start (ASS) feature started acting up (not functioning). A few days later the ASS turned the engine off and did not restart automatically—in the middle of heavy traffic during rush hour. The ASS light came on. The engine started manually, and we got it home. Battery was dead the next morning. I charged it up and took the car to the local mechanic for a quick assessment. The battery was fine, charging, but the car threw a Code: P0871 Transmission Fluid Pressure Sensor Switch. This mechanic told us that there was a Technical Service bulletin through Subaru that addressed this issue but was also aware that it could be caused by the ASS killing the battery OR other electronic modules which fail to enter sleep mode—which would also cause random lights to come on. An appointment was made to take the car into Peoria Subaru, thinking it would be something they could diagnose easily. It had previously been in for the routine oil change with the inspection. When we dropped the car off, I provided the Advisor the code and a associated TSB for the code. We got the car back that day and were told the following: The tech found that the car currently has a “Aftermarket” AGM battery. Subarus require a “Enhanced Flooded Battery” which would explain multiple codes found for loss of communications and parasitic battery drain--for systems that don't go to "sleep" when the car is not running.

Filed May 20, 2026 · Electrical · TX

Parasitic drain on battery. Can be available for inspection upon request.

Filed Sep 11, 2023 · Electrical · PA

Repeated dead battery with no known cause

Filed Jun 27, 2023 · Electrical · MI

Multiple occasions of dead battery or stalling in an intersection have occurred since the car was 6 months old, with mileage of only 3,000 miles. Dead battery accompanied by electrical malfunctions such as loss of nav system, climate control system, and driving safety systems. Battery failure in cold weather in Michigan winter resulting in long waits for tow truck. Loss of heat in very cold temps on a road trip.

Filed Aug 25, 2022 · Electrical · WI

The car was not used for two weeks (parked at home garage). When we came back from our trip, the battery died. Everything (lights etc.) had been turned off. The tow service came to jump started my car, and I drove to the dealership. I took it to the dealership, they inspected the car, recharged the battery, sent me home. The service person suggested I put in a battery tender to keep car outback charged while being away for a while. The car was purchased in late May 2022. If we had driven the car to park at airport while we were on vacation, we would have been stranded at the parking lot. A safety hazard! Apparently the dead battery issue with Subaru Outback is an known issue.

Filed Aug 4, 2022 · Electrical · NJ

Battery drained, car would not start. First occurrence with new car at 831 miles, battery diagnosed as defective and replaced by manufacturer. Second occurrence at 4620 miles after sitting unused 8 days at airport parking, battery drained and most "check engine" lights on after jump-starting. EyeSight and most safety features disabled until checked and reset by manufacturer. Manufacturer quote "CAUSE: Problem due to vehicle sitting for more than a week low battery voltage concern. Recharged battery and it passes test. 100009 No problem found." Maintenance rep said car is working to specs. However a periodic dead battery to seniors who do not drive daily but desperately need a reliable car in case of sudden emergencies is cause for a safety concern.

Filed Aug 1, 2022 · Electrical · NV

Battery dies or runs so low the vehicle won’t start, if a door/hatchback is left open just a short time with the engine turned off. Or if the key fob is in the cab more than a few minutes with the engine off, or the accessory function is used more than a few minutes with the engine off. I bought the car on July 21st 2022. On July 26st 2022 I was driving it on a Jeep road and pulled over and stopped for 10-15 minutes, car/engine turned off. When I returned the car wouldn’t start. I tried to start it repeatedly. It appeared to be a low battery. I may have left the door ajar but don’t believe so. I did sit in the car a few minutes with the engine off. My phone was plugged in to the car and I used it for a few minutes. I possibly could have left the key fob in the car but don’t think so. About 15 minutes later, after exiting the vehicle, I got back in and it started. I researched online and found this has been a problem with Subaru Outbacks. Lawsuits have been filed. I called the dealership and talked to the salesman and he said he had no idea why my car hadn’t started. Which I find hard to believe. If this had happened a few miles further out in the desert and I was gone from the car longer and the battery completely failed it would have been a life threatening situation. It was a 100 degree day and phone reception was spotty. I’m 67 and had water but a 6 mile walk back to civilization wouldn’t have been easy. I’ve read that many Outback owners carry a jump-start device-battery. I’ll get one, they’re cheap. But still the dealerships and Subaru should inform/warn customers of this issue BEFORE they buy or leave the premises. I wouldn’t have bought the car if I knew. Subaru’s are marketed as outdoor friendly and this model, the Wilderness, supposedly designed just fit that. How many people are being stranded in dangerous situations? Leaving the hatchback open while camping as they unload the car engine off-dead battery. I’ve heardrumors online of a software fix

Filed Feb 24, 2022 · Electrical · CO

Battery completely died on a nearly brand new car overnight, after being parked for less than 48h at temperatures around 5°F. Took it to a dealer who claims that the LED dome light was left on, draining the battery. However, the dome light is an LED light rated at about 100mA @ 13V, and the battery is rated over 100 Amp-hours (de-rated to 45% at ~0°F, so a single dome light by itself should take around ~450 hours to drain a fully-charged battery. It seems like even brand new Subaru Outback 2022s are affected by major parasitic drain battery issues.

Filed Jan 3, 2022 · GA

After 2 week of new car ownership--battery dead. Only 359 miles on the car

Filed Dec 8, 2021 · Electrical · NY

Car is suffering from "Parasitic Drain". Car is brand new with only a little over 200miles on it. Dealer has had to tow in the car twice already. Battery has been replaced. Car has so far been DOA 3 times in Driveway with a weeks' time.