2021 Subaru Outback Problems: 13 Known Issues

On the 2020-2022 Subaru Outback, certain 2020-2022 Outback (and Legacy) vehicles have defective Aisin Occupant Detection System sensors in the front passenger seat. A defect in the ODS sensor printed circuit board can crack a capacitor; moisture entering the capacitor causes a short circuit. This illuminates the SRS airbag warning lamp and the front passenger frontal-airbag OFF indicator, and the front passenger airbag may fail to deploy in certain crashes, increasing injury risk to an occupant. About 103,114 Outbacks were among the 118,723 vehicles recalled.

On the 2020-2026 Subaru Outback, owners report EyeSight Pre-Collision Braking warning and braking hard when there is no real obstacle in the path, for example on a curve with a stopped or parked car off to the side, in rain, when facing low sun, or on a clear road. A sudden stop like this can leave following traffic little room. Dealers have not always found a fault, so the cause on a given car has not been confirmed. Applies to: EyeSight-equipped 2020-2026 Outback. Owner reports cover the 2020-2025 sixth-generation Outback and, so far in two NHTSA complaints, the 2026 seventh-generation Outback, which uses a different EyeSight system with three forward cameras and radar.

On the 2020-2025 Subaru Outback, owners report the DriverFocus driver-monitoring camera repeatedly showing "Driver Monitoring System disabled" and switching itself off, most often in low or side sunlight or with sunglasses, and in some cases at random times; while it is off, the distraction and drowsiness alerts are not working. Separately, Subaru bulletin 07-225-24 covers 2023-24 Outbacks whose EyeSight stereo camera enters a temporary halt mode (halt code E5), stores DTC B28A6, or stops its cooling fans with DTC B28C7 after sitting in high humidity or heat. Applies to: Sixth-generation (2020-2025) Outbacks equipped with DriverFocus. For 2024, Subaru lists DriverFocus as standard on Touring, Limited XT and Touring XT, optional on Limited, and not available on Base, Premium, Onyx Edition, Onyx Edition XT or Wilderness; for 2025 it became standard on Limited. The EyeSight halt part applies to 2023-24 Outbacks covered by bulletin 07-225-24 (software built into production from Outback VIN R3021303). For early 2020 models only, bulletin 07-176-20R adds monitoring-unit software for DTCs B118B, B11E5 and B11E6 appearing together.

On the 2020-2023 Subaru Outback 2.5L FB25 naturally aspirated H4, multiple 2020-2023 Outback owners with the 2.5L FB25 engine report failure of the thermo control valve assembly, which can trigger a check engine light, disable normal coolant flow control, and in some cases lead to overheating or poor heater performance. Subaru issued a warranty extension and service communications because the valve's internal position sensor/motor can fail. Owners commonly see the problem well before 100,000 miles, often with no prior cooling-system symptoms.

On the 2021-2023 Subaru Outback, an insufficient weld between the switch stator and cover of the transmission inhibitor (park/neutral start interlock) switch allows water intrusion over time, causing the switch to become inoperative. When it fails, the reverse lights do not illuminate and the rearview/backup camera image does not display when the vehicle is shifted into reverse, increasing the risk of a backover crash. Subaru recalled certain 2021-2023 Outback (and Legacy, plus 2021 Crosstrek and 2022 Forester) vehicles; roughly 51,470 Outbacks were among the ~95,830 total affected.

On the 2015-2024 Subaru Outback, like many modern automakers, Subaru switched to soy/plant-based wire insulation, and owners widely report that rodents (mice/rats) are attracted to and chew through the harnesses, causing warning lights, no-starts, sensor faults, and blown fuses. Documented Outback repair bills range from ~$1,500 to $3,500+, with damage found in the engine-bay harnesses, MAP/MAF wiring, fuel lines, and even dash harnesses. The soy-insulation issue has spawned class-action litigation against several manufacturers including Subaru. Owners report being unaware of the vulnerability at purchase, and standard warranty typically excludes 'rodent/animal damage,' pushing the cost onto comprehensive insurance or the owner.

On the 2020-2024 Subaru Outback, owners of 2020-2024 Outbacks frequently report power rear gate problems including failure to open or close, repeated beeping, stopping mid-travel, or reversing unexpectedly. Subaru issued service information for rear gate control module logic and initialization issues, and owner complaints commonly describe the hatch becoming unusable until reset or repair. In some cases the problem is tied to low system voltage, latch alignment, or module/software faults.

On the 2010-2022 Subaru Outback, outbacks with a sunroof/moonroof commonly develop interior water leaks caused by clogged, kinked, or (on some 2020 Touring XT builds) factory-blocked sunroof drain tubes. Rather than draining out, water backs up in the sunroof frame and overflows into the headliner and down the A-pillars, soaking the front and rear footwells, wetting carpet/underlay, and in some cases flooding audio/electrical components under the seats — which can then cause secondary electrical faults and musty odors/mold. Subaru has issued service bulletins for water intrusion (e.g., leaks appearing at the map-light/overhead area on 2010-2013 Legacy/Outback). Complaints span many model years and generations.

On the 2015-2022 Subaru Outback, the forward-mounted A/C condenser and its connecting refrigerant lines are vulnerable to leaks - sometimes from road-debris/stone damage to the thin condenser, sometimes from a damaged line or failed O-ring at a hose connection. The system slowly loses refrigerant and cooling fades, with reports on low-mileage cars including a 2022 Onyx at ~5,800 miles found with a damaged condenser line. Because the condenser sits at the front, it isn't economically repairable and must be replaced.

On the 2020-2024 Subaru Outback, owners have reported front seat heaters that stop working, heat unevenly, or become excessively hot in localized areas. Complaints and forum reports point to failures in the seat heater element, thermostat/control logic, or seat cushion wiring within this generation. The issue is more than comfort-related when overheating occurs, as some owners describe burning sensations or needing to shut the heater off immediately.

On the 2015-2022 Subaru Outback, owners report a speed-dependent whine/howl or turbine-like noise from the rear/undercarriage that turns out to be the rear differential or a driveline carrier bearing rather than a wheel bearing. The tell-tale difference: differential and driveshaft-related noise rises in pitch about 4x as fast as road speed (and often changes on accel vs coast/decel), while wheel-bearing noise scales ~2x with speed and shifts with cornering load. Causes include premature rear-diff gear-surface wear under severe use (steep grades, extreme weather, towing) and worn carrier/center-support bearings. Subaru issued a service bulletin (03-87-21) addressing rear differential noise and introduced a higher-viscosity gear oil to better protect gear surfaces under demanding conditions.

On the 2010-2024 Subaru Outback, owners across multiple Outback generations report premature wheel hub bearing failure, most commonly showing up between roughly 80,000 and 120,000 miles. The classic symptom is a low-pitched droning/humming or 'beehive' noise that begins around 45-55 mph and gets louder with speed, and that changes pitch when the car is loaded up in a curve (louder turning one direction, quieter the other). Subaru hubs frequently fail WITHOUT the traditional 'play' you can feel by rocking the wheel, which leads to misdiagnosis as tire noise. Some owners report replacing three separate bearings on a single car. A useful field test is an infrared thermometer after a highway drive: a failing bearing runs noticeably hotter (~150F+) than its healthy siblings (~120F).

On the 2013-2024 Subaru Outback, a very common owner complaint is that the Outback's rear brake pads and rotors wear out dramatically faster than the fronts — often gone by 20,000-40,000 miles while the fronts still have most of their life. Multiple owners report metal-on-metal rear pads and scored rotors at low mileage, sometimes replaced twice before the fronts need service (the reverse of most cars). The cause is design/software: the Outback uses the ABS/VDC system as an electronic brake-force distributor and biases braking rearward for straight-line stability, while the rear pads/rotors are physically smaller than the fronts. Stability control and hill-holder also drag the rears. It rarely leaves owners stranded but is a recurring, unexpected maintenance expense.