2020 Subaru Legacy Engine Problems
- Complaints
- 4about this part
- Share
- 3%of 121 total for the year
- Median mileage
- —not reported
- Trend
- Not enough dataFewer than 15 complaints, too few for a reliable trend.
NHTSA recorded 4 complaints about the engine of the 2020 Subaru Legacy, 3% of the 121 complaints for this model year. 1 a fire, according to the filers.
Fewer than 15 complaints name this part, so treat the figures as a rough indication only.
Example complaints
Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.
“Thermo Control Valve has malfunctioned. It disables all driver assistance, like lane assist, blind spot, RAB, collision braking, etc. I have seen on many forums that this is a known issue, across multiple vehicles from Subaru from 2019 to about 2021. The was a TSB put out about a new and improved part to fix this known issue.”
NHTSA complaint #11544993, filed 2023-09“One hour into traveling on the highway smoke began to come from under the hood so we pulled off to the side of the road. Upon opening the hood, after the smoke cleared, a fire was observed. At that point the passengers exited the vehicle and called 911. There was no warning lights or sounds indicating any problems prior to this. The car burned very quickly and the firefighters extinguished the fire but not before the entire car was burned to ashes. The car is wrapped and in the possession of the insurance company pending investigation.”
NHTSA complaint #11674078, filed 2025-07“Check engine light came on at 55,500 miles on exactly the third anniversary of purchase. Local mechanic determined the code related to Thermo Control Valve failure. Apparently an ongoing issue with many Subarus since replacing the thermostat with this in their cars. Lost all eyesight features, including cruise control and high beams, as well as cabin heat in the midst of winter in the northeast. A simple google search reveals MANY instances of this subpar part falling on Subaru cars. $1,066 later, I feel a recall or coverage under powertrain warranty is warranted.”
NHTSA complaint #11509131, filed 2023-02Related service bulletins
- 11036811Aug 20, 2026This service bulletin outlines the diagnostic and repair procedure for white smoke emitted from the exhaust after startup. This is an revised version of the original bulletin.
- 11034269Jun 30, 2026This bulletin provides updated parts information and a service procedure to follow for removing accumulated carbon deposits from fuel injectors and internal engine components…
- 11034264Jun 26, 2026This bulletin provides updated parts information and a service procedure to follow for removing accumulated carbon deposits from fuel injectors and internal engine components…
- 11034257Jun 23, 2026This bulletin outlines the diagnostic and repair procedure for white smoke emitted from the exhaust after startup.
- 11034237Jun 1, 2026"This bulletin provides a new diagnostic procedure for vehicles equipped with a Denso CP 1, 1.5 and 2.5 head units to provide an enhanced version of the troubleshooting steps for…
- 11033065May 13, 2026This bulletin provides updated parts information and a service procedure to follow for removing accumulated carbon deposits from fuel injectors and internal engine components…
- 11033051May 1, 2026This bulletin announces the diagnostic procedures to be used when DTCs B1571(REFERENCE CODE INCOMPATIBILITY IMMOBILIZER CM TO ECM) and B1572(IMM CIRCUIT EXCEPT ANTENNA CIRCUIT)…
- 11027982Jan 12, 2026This Bulletin provides the diagnostic procedure for the STARLINK® Remote Engine Start (RES).
- 11027978Jan 8, 2026This bulletin announces the design change made to the high-pressure fuel pump developed to prevent DTC P0087 (Fuel Rail/System Pressure – Too Low Bank 1).
- 11027103Dec 23, 2025This Service Information Bulletin outlines a new required procedure to follow when performing immobilizer-related repairs on models listed.
Engine: other model years
| Year | Complaints | Share of year |
|---|---|---|
| 2025 | 3 | 50% |
| 2024 | 1 | 6% |
| 2022 | 1 | 3% |
| 2021 | 2 | 6% |
| 2020 | 4 | 3% |
| 2019 | 6 | 5% |
| 2018 | 10 | 9% |
| 2017 | 5 | 4% |
| 2016 | 7 | 5% |
| 2015 | 23 | 14% |
| 2014 | 5 | 9% |
| 2013 | 18 | 27% |
| 2012 | 23 | 26% |
| 2011 | 22 | 13% |
| 2010 | 31 | 21% |
| 2009 | 7 | 11% |
| 2008 | 4 | 6% |
| 2007 | 7 | 21% |
| 2006 | 16 | 18% |
| 2005 | 4 | 2% |
| 2004 | 5 | 10% |
| 2003 | 4 | 7% |
| 2002 | 4 | 7% |
| 2001 | 3 | 4% |
| 2000 | 1 | 1% |
| 1999 | 2 | 2% |
| 1997 | 1 | 1% |
Other parts of the 2020 Subaru Legacy
66 complaintsOther or unknown
26 complaintsElectrical system
15 complaintsForward collision avoidance
7 complaintsTransmission and drivetrain
7 complaintsVehicle speed control
4 complaintsBrakes
2 complaintsLane departure
2 complaintsAir bags
1 complaintsBack-over prevention (rear camera)
1 complaintsExterior lighting
1 complaintsFuel system
1 complaints
← All problems reported for the 2020 Subaru Legacy
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 27, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.
To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology