Subaru has a reputation for building vehicles that are both sporty and capable. Their all-wheel-drive models are a staple in snow-prone areas and owners are fiercely loyal to the brand. Powered by various boxer engines over the years, the Subaru Legacy was a mix of sporty and sensible transportation. In its 7th and final generation, the 2020-2025 Subaru Legacy was a North America exclusive built in the United States. While the Legacy may have bowed out, some nagging issues were left behind.
The information presented below was collected from NHTSA.gov complaints, recall information, various Facebook groups and online forums plus experience from covering the industry for the last 15 years.
Defective Airbag Sensors
Airbag systems are fairly complex. In order to make sure an airbag is only deployed when needed, manufacturers use special sensors in the seats to detect if someone is sitting in it. Dubbed the Occupant Detection System (ODS) these sensors determine not only if someone is in the seat, but some can even detect their weight to help decide how the airbags are deployed. Unfortunately a run of 2020-2022 Subaru Legacy vehicles may have a defective ODS sensor. According to NHTSA recall #24V-227 an issue with a capacitor on the ODS sensor circuit board could lead to a short circuit. If that happens the passenger side airbag may not deploy when needed. Subaru is swapping out all four ODS sensors on affected vehicles at no charge to remedy the problem.
Fuel Pump Failure
Many modern vehicles have two fuel pumps: a lower pressure pump (usually located in the fuel tank) and a high pressure pump (usually on or inside the engine itself). The low pressure fuel pump feeds the high pressure pump. But if the low pressure pump can’t get fuel to the high pressure pump, things go wrong. In the case of NHTSA recall #21V-587 for 2018-2020 Subaru Legacy models an issue with the low pressure fuel pump impeller is the main problem. The impeller is what actually moves the fuel. When the low pressure fuel pump fails the engine may stall or fail to start. Subaru has an improved fuel pump design and is swapping out units on affected vehicles for free.
Bad Transmission Switch
There are so many interconnected systems on a modern vehicle. A failure in one component can cascade across multiple areas. In this case a bad park/neutral interlock switch could cause a few problems. When the transmission is put into reverse the backup lights may not turn on and the backup camera view may not display on the dash screen. In some cases the engine may not start due to the onboard computer not knowing if the transmission is in Park. Per NHTSA recall #23V-755 the culprit is a bad weld that may allow water to enter the switch causing it to fail. Anyone with an affected 2021-2023 Subaru Legacy can have a new transmission switch installed for free at their Subaru dealership.
Snapped Transmission Drive Chain
Nearly 200,000 2019-2020 Subaru vehicles were hit with a unique problem: the transmission drive chain could break. These Subarus used a continuously variable transmission (CVT) that uses a special chain to give an infinite range of gear ratios. A batch of 2020 Subaru Legacy vehicles were caught up in NHTSA recall #21V-955 along with their fellow Subaru Outback and Subaru Ascent stable mates. An issue with how the transmission control unit (TCU) was programmed could allow for the drive chain to slip under certain conditions. If the drive chain slipped enough over time it could fail, leading to a loss of power. Dealers were instructed to inspect the physical drive chain and stored TCU data to determine if the drive chain was damaged. If the drive chain was indeed damaged, then the entire transmission is to be replaced at no cost.
Leaky Thermo Control Valve
“The Thermo control valve is faulty and my friends is too. There is a class action lawsuit concerning this part. I replacement part was designed in 2021 and Subaru is aware of this issue, but refuses to do a recall. So far 2019, 2020 and 2021 models are affected.“ NHTSA ID #11578035
“The engine thermo control valve has been defective and Subaru has known this issue since 2022 and has tried to do some software update but it is defective [XXX] ) despite multiple tries. This can overheat an engine, result in the front collision warning system (eyesight) and rear auto-braking not working.” NHTSA ID# 11565945
“Thermo Control Valve failed. Caused a short which affected all electrical components on its circuit. The car became inoperable in traffic.” – NHTSA ID# 11549397
Instead of using a mechanical thermostat to control engine coolant flow, Subura chose an electronic valve. Unfortunately there was a problem with coolant vapor seeping into the valve itself and causing damage. For 2020-2022 Subaru Outback owners the problem may show up as a check engine light or in rare situations the vehicles may shut down while driving. A 15 year / 150,000 mile extended warranty for the affected vehicles was issued along with technical service bulletin #09-119-24 detailing the situation.
Dead Factory Battery
This isn’t a recall but a technical service bulletin (TSB #07-213-22R) for 2020-2023 Subaru Legacy models. It seems that the original battery (SOA821B700) wasn’t quite up to the demands of the vehicle’s electrical system and was prone to dying. Subaru addressed the problem by fitting a larger capacity battery (SOA821B900) under warranty. The new battery is slightly larger, so a few modifications have to be made to make it fit. While the warranty period is likely over for most of the affected vehicles, anyone looking to buy one of these vehicles should be aware of the problem.
Conclusion
Subaru discontinued the Legacy at the end of 2025 after a 36 year run. The head gasket issues that plagued earlier Subaru boxer engines are largely a thing of the past. As are Subaru CVT issues for the most part, with issues being more of an exception than the rule. If you are in the market for a 2020-2025 Subaru Legacy your best bet is to drop the vehicle’s VIN into the NHTSA recall tool. If the VIN checks out, make sure to get a pre-purchase inspection by an independent local shop before completing the purchase.
