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.
2020 Subaru Legacy
Owner reports · Recalls · Investigations
Similar to other model years
Owner complaints for the 2020 Subaru Legacy do not stand out strongly from the model-year median of 77.
About this comparison →How this year compares
Owner complaints by model year
Compare all Legacy years →Counts vary with age, sales and reporting. They are not failure rates.
What owners reported most
All reported categories
Tap a category to read its complaints. One report may name several components.
When problems were reported
Mileage at the reported incident
52 reports with mileage · 69 unknown
NHTSA’s mileage field refers to the reported incident, not necessarily the filing date. This shows report counts, not the likelihood of a failure.
What to inspect
Issues worth paying extra attention to based on owner reports.
- Visibility/wiper. Review the 57 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
- Electrical System. Review the 15 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
- Visibility. Review the 9 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
NHTSA owner reports · September 18, 2026 snapshot.
What owners actually said
121 reportsThe contact owns a 2020 Subaru Legacy. The contact stated that there was a crack on the front windshield that was not caused by an impact. The vehicle was taken to a dealer and the front windshield was replaced; however, the failure reoccurred. The manufacturer was contacted and stated that the contact would receive a callback. …
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The contact owns a 2020 Subaru Legacy. The contact stated that there was a crack on the front windshield that was not caused by an impact. The vehicle was taken to a dealer and the front windshield was replaced; however, the failure reoccurred. The manufacturer was contacted and stated that the contact would receive a callback. The failure mileage was 8,000.
The contact owns a 2020 Subaru Legacy. The contact stated while driving at an undisclosed speed, the contact stated that several unknown warning lights illuminated, and the gear shifter was inoperable. The contact stated that the transmission failed to shift as needed. The vehicle was towed to the dealer but was not diagnosed or…
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The contact owns a 2020 Subaru Legacy. The contact stated while driving at an undisclosed speed, the contact stated that several unknown warning lights illuminated, and the gear shifter was inoperable. The contact stated that the transmission failed to shift as needed. The vehicle was towed to the dealer but was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 69,738.
Windshield spontaneously cracked at top. I came outside in the morning after a temperature fluctuation and there was a crack at the top with one piece of the glass sitting lower… it has since grown. I have been forced to drive with the crack as Subaru will do anything to not honor a warranty, ever. The eyesight I am learning i…
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Windshield spontaneously cracked at top. I came outside in the morning after a temperature fluctuation and there was a crack at the top with one piece of the glass sitting lower… it has since grown. I have been forced to drive with the crack as Subaru will do anything to not honor a warranty, ever. The eyesight I am learning is necessary for the vehicle to avoid front end collisions and to properly deploy the airbag. The crack started in November, it’s almost August, and I cannot get it replaced under the warranty I paid. I see many people have the same problem. You can even see where the windshield cracked where an iPass was mounted from a temperature change. The wipers also cannot keep up with moderate rain, causing rain blindness in moderate precipitation and the lightest rain will turn off the eyesight causing a malfunction that will not assist in avoiding a collision. In addition, I will be complaining with the CFTC for the warranty issues. I cannot even get records of my warranty or service. Example: window regulator was a problem off the log, and salesman used it as an example, service won’t repair. I regret buying a Subaru, they claim to be safe and reliable with great service, I am only having problems that affect the safe operation of the vehicle and I paid all this extra for full bumper to bumper and they tell me that it doesn’t exist. In addition, that vehicle claims to get close to 30mpg, I am being completely honest when I say I had about the same mileage in a 1995 Cadillac Deville, and the mileage I got in a 2009 BMW twin-turbo far exceeded the mpg. I tried to get it repaired today under warranty. I was yelled at that it was an impact, and I wish I knew… would have said, “is it more likely that I’m lying or the company that’s been successfully sued 4 times for this exact problem is at fault?” Perhaps there was a light impact in the months AFTER it broke parked in a unheated garage.
Center console/head unit will regularly lock up and eventually reboot when Apple CarPlay is in use, cruise control, lane keep will turn off, and car will warn that ADAS is not available, backup camera does not work during this time. HVAC controls are not accessible during this time as well
2020 Subaru Legacy Touring XT - Windshield cracked for no apparent reason. No stone or rock chips visible. Had same issue on previously owned 2015 Subaru Legacy. The crack starts at the base of the passenger side where heat strips are located to keep the wiper blades from freezing. The cracked windshield may cause the Subar…
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2020 Subaru Legacy Touring XT - Windshield cracked for no apparent reason. No stone or rock chips visible. Had same issue on previously owned 2015 Subaru Legacy. The crack starts at the base of the passenger side where heat strips are located to keep the wiper blades from freezing. The cracked windshield may cause the Subaru EyeSight safety system to malfunction, putting all passengers at risk for a potential accident. I had it inspected at a Subaru dealership. The service technician confirmed that this was a know problem. He suggested I call Subaru of America for assistance. I'm still within the 3 year warranty period but windshields are not covered. He said Subaru dealerships do not repair windshields. They will engage a 3rd party repair shop if needed. My vehicle is included in a pending class action lawsuit against Subaru for this issue. Safelite Autoglass estimated my windshield replacement at $1,035.00 (without insurance).
windshield crack in lower part on passenger side for no apparent reason.
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 hig…
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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.
Windshield cracked for no apparent reason. May cause the Subaru EyeSight safety system to malfunction. Crack started at the bottom of passenger side windshield where the heat strips are located for wiper blades not to freeze.
A crack appeared in the windshield overnight while parked in the driveway with no sign of impact or other causes. This seems to be an ongoing problem with Subaru since they changed to acoustic glass for their windshields.
Official recalls
624V227000 · Air Bags:sensor:occupant Classification:front Passenger
Mar 22, 2024
Subaru of America, Inc. (Subaru) is recalling certain 2020-2022 Outback and Legacy vehicles. A capacitor in the sensors for the Occupant Detection System (ODS) may crack and short circuit, which can prevent the front passenger air bag from deploying in a crash.
Consequence & remedy
Consequence: An air bag that does not deploy during a crash can increase the risk of injury.
Remedy: Dealers will replace the ODS sensors on the front passenger seat, free of charge. Owner notifications were mailed February 3, 2025. Owners may contact Subaru customer service at 1-844-373-6614. Subaru's number for this recall is WRA-24.
22V485000 · Power Train:automatic Transmission:control Module (tcm/pcm/tecm); Power Train:driveline:chain/belt
Jul 8, 2022
Subaru of America, Inc. (Subaru) is recalling certain 2020-2021 Outback and Legacy vehicles. A programming error in the Transmission Control Unit (TCU) may allow the clutch to engage before the drive chain is completely clamped.
Consequence & remedy
Consequence: An improperly secured drive chain may slip and break, causing a loss of drive power and increasing the risk of a crash.
Remedy: Dealers will reprogram the TCU, inspect TCU data for chain slip, and visually inspect the chain guide. If evidence of chain slippage or damage is found, the transmission will be replaced. Repairs will be performed free of charge. Owner notification letters are expected to be mailed August 24, 2022. Owners may contact Subaru's customer service at 1-844-373-6614. Subaru's number for this recall is WRK-22. This recall is an expansion of previous recall number 21V-955.
Additional source detail variants (2)
Power Train:driveline:chain/belt
Subaru of America, Inc. (Subaru) is recalling certain 2020-2021 Outback and Legacy vehicles. A programming error in the Transmission Control Unit (TCU) may allow the clutch to engage before the drive chain is completely clamped.
Consequence: An improperly secured drive chain may slip and break, causing a loss of drive power and increasing the risk of a crash.
Remedy: Dealers will reprogram the TCU, inspect TCU data for chain slip, and visually inspect the chain guide. If evidence of chain slippage or damage is found, the transmission will be replaced. Repairs will be performed free of charge. Owner notification letters are expected to be mailed August 24, 2022. Owners may contact Subaru's customer service at 1-844-373-6614. Subaru's number for this recall is WRK-22. This recall is an expansion of previous recall number 21V-955.
Power Train:automatic Transmission:control Module (tcm/pcm/tecm)
Subaru of America, Inc. (Subaru) is recalling certain 2020-2021 Outback and Legacy vehicles. A programming error in the Transmission Control Unit (TCU) may allow the clutch to engage before the drive chain is completely clamped.
Consequence: An improperly secured drive chain may slip and break, causing a loss of drive power and increasing the risk of a crash.
Remedy: Dealers will reprogram the TCU, inspect TCU data for chain slip, and visually inspect the chain guide. If evidence of chain slippage or damage is found, the transmission will be replaced. Repairs will be performed free of charge. Owner notification letters are expected to be mailed August 24, 2022. Owners may contact Subaru's customer service at 1-844-373-6614. Subaru's number for this recall is WRK-22. This recall is an expansion of previous recall number 21V-955.
21V955000 · Power Train:automatic Transmission:control Module (tcm/pcm/tecm); Power Train:driveline:chain/belt
Dec 9, 2021
Subaru of America, Inc. (Subaru) is recalling certain 2019-2020 Ascent, 2020 Legacy and Outback vehicles. A programming error in the Transmission Control Unit (TCU) may allow the clutch to engage before the drive chain is completely clamped.
Consequence & remedy
Consequence: An improperly secured drive chain may slip and break, causing a loss of drive power and increasing the risk of a crash.
Remedy: Dealers will reprogram the TCU, inspect TCU data for chain slip, and visually inspect the chain guide. If evidence of chain slippage or damage is found, the transmission will be replaced. Repairs will be performed free of charge. Owner notification letters were mailed August 19, 2022. This recall includes all vehicles previously recalled under 19V-855. Vehicles previously recalled under 19V-855 will need to have the new remedy performed for this recall once available. Owners may contact Subaru customer service at 1-844-373-6614. Subaru's number for this recall is WRK-21.
Additional source detail variants (2)
Power Train:driveline:chain/belt
Subaru of America, Inc. (Subaru) is recalling certain 2019-2020 Ascent, 2020 Legacy and Outback vehicles. A programming error in the Transmission Control Unit (TCU) may allow the clutch to engage before the drive chain is completely clamped.
Consequence: An improperly secured drive chain may slip and break, causing a loss of drive power and increasing the risk of a crash.
Remedy: Dealers will reprogram the TCU, inspect TCU data for chain slip, and visually inspect the chain guide. If evidence of chain slippage or damage is found, the transmission will be replaced. Repairs will be performed free of charge. Owner notification letters were mailed August 19, 2022. This recall includes all vehicles previously recalled under 19V-855. Vehicles previously recalled under 19V-855 will need to have the new remedy performed for this recall once available. Owners may contact Subaru customer service at 1-844-373-6614. Subaru's number for this recall is WRK-21.
Power Train:automatic Transmission:control Module (tcm/pcm/tecm)
Subaru of America, Inc. (Subaru) is recalling certain 2019-2020 Ascent, 2020 Legacy and Outback vehicles. A programming error in the Transmission Control Unit (TCU) may allow the clutch to engage before the drive chain is completely clamped.
Consequence: An improperly secured drive chain may slip and break, causing a loss of drive power and increasing the risk of a crash.
Remedy: Dealers will reprogram the TCU, inspect TCU data for chain slip, and visually inspect the chain guide. If evidence of chain slippage or damage is found, the transmission will be replaced. Repairs will be performed free of charge. Owner notification letters were mailed August 19, 2022. This recall includes all vehicles previously recalled under 19V-855. Vehicles previously recalled under 19V-855 will need to have the new remedy performed for this recall once available. Owners may contact Subaru customer service at 1-844-373-6614. Subaru's number for this recall is WRK-21.
21V587000 · Fuel System, Gasoline:delivery:fuel Pump
Jul 29, 2021
Subaru of America, Inc. (Subaru) is recalling certain 2019-2020 Ascent, 2018 Forester, 2018-2020 Impreza, Legacy, Outback, 2018-2019 BRZ, WRX, and Toyota 86 vehicles. The low-pressure fuel pump inside the fuel tank may fail.
Consequence & remedy
Consequence: Fuel pump failure can cause an engine stall while driving, increasing the risk of a crash.
Remedy: Dealers will replace the low-pressure fuel pump, free of charge. Owner notification letters were mailed September 24, 2021. Subaru and Toyota owners may call customer service at 1-844-373-6614. Subaru's number for this recall is WRG-21.
20V766000 · Back Over Prevention:display Function
Dec 10, 2020
Subaru of America, Inc. (Subaru) is recalling certain 2020 Legacy and Outback vehicles equipped with "high" grade and "mid" grade multimedia navigation. The August 2020 over-the-air software update may have timed out without completing the installation, corrupting the data, and causing the rearview display to shutoff intermittently. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 111, "Rear Visibility."
Consequence & remedy
Consequence: The intermittent loss of the rearview image reduces the driver's visibility and increases the risk of crash.
Remedy: Subaru will notify owners, and dealers will reprogram the software and, if necessary, replace the Cockpit Control Module, free of charge. The recall began January 22, 2021. Owners may contact Subaru customer service at 1-844-373-6614. Subaru's number for this recall is WRH-20.
19V664000 · Service Brakes, Hydraulic:pedals And Linkages
Sep 18, 2019
Subaru of America, Inc. (Subaru) is recalling certain 2020 Outback and Legacy vehicles. The brake pedal mounting bracket may have a missing or insufficiently tightened bolt.
Consequence & remedy
Consequence: A missing or loose bolt may cause the brake pedal mounting area to deform over time, which can reduce braking performance and increase the risk of a crash.
Remedy: Subaru will notify owners, and dealers will inspect the brake pedal mounting bracket hardware and replace the hardware or brake pedal assembly, as necessary, free of charge. The recall began October 1, 2019. Owners may contact Subaru customer service at 1-844-373-6614. Subaru's number for this recall is WUL-97.
Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗
NHTSA investigations
0No exact-year investigations in this snapshot.
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