Subaru Legacy lane assist problems

Filed Apr 23, 2026 · Brakes, Driver assistance · NE

All Safety features stopped working while driving multiple times and loading feature pops up on the display screen. Speakers will go mute randomly, no sound will emit including phone calls. Automatic stop feature has engaged on the interstate multiple times, locking breaks (This is extremely dangerous) and lane assist does not recognize the difference between a lane or tar strips road patches. Will Automatically move the car into the next lane, even when a vehicle is in the lane. I have reported the issues to the dealership I bought my vehicle from. Also have cam footage of electrical issues.

Filed Jan 23, 2026 · Driver assistance, Electrical · GA

The infotainment touchscreen in my 2018 Subaru Legacy experiences “ghost touch,” where the screen registers inputs without driver interaction and becomes unresponsive. While driving, the screen changes settings on its own and distracts the driver. As a result of the touchscreen malfunction, critical safety features including Blind Spot Warning and Lane Keeping Assistance became disabled. This directly impacted safe vehicle operation. The issue was diagnosed by an authorized Subaru dealership, which confirmed the head unit is defective and requires replacement. Subaru previously issued a warranty extension for this known defect. Subaru of America denied goodwill assistance despite the safety-related nature of the defect.

Filed Jul 29, 2024 · NC

Without any reason a random issue came up. Special feature components lit up on dashboard. Everything but “check engine lit up and the car features were disabled. Disabled items were eye sight, lane assist, ABD, electrical parking brake, hill assist, vehicle dynamics control. With all these lights on my power steering was also disabled. Took to dealer a year ago and all they did was “updated computer system. 3 months later the t started happening again but only intermittently but for past 3 days it’s been constant

Filed Jan 17, 2024 · Engine · TX

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. Specific to my case, the front and rear collision warning systems are off, auto lane departure avoidance system is off, the engine can overheat and has had reduced performance, and the check engine lights are also on. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Dec 20, 2023 · MN

We recently purchased a used 2020 Subaru Legacy sedan with ~33,000 miles on it. It has a salvage title due to previous owner hitting a deer, (no air bag deployed, just minor body work) and it was professionally repaired to "like-new" condition. Last weekend, when starting the car, the check engine light and a bunch of other warning lights came on. An OBDI scan showed a code of "P263A" indicating a problem with the Thermo Control Valve. As a result of the defective TCV, several major functions of the vehicle were automatically disabled: adaptive cruise control, eyesight system with lane keeping, automatic braking, as well as all cabin heating, windshield defrost function, and the engine temperature gauge. Without these systems properly working, the drivability of the vehicle is greatly impaired, especially in a Minnesota winter without a functional windshield defrost and engine temperature monitoring gauge. When taking the car into the local Subaru dealership for full diagnostics, they confirmed that indeed the TCV was bad, and quoted me a cost of $1135 to replace it. They claimed that since the car has a salvage title, Subaru's warranty will not cover any part of this repair. However, there is a known wide-spread failure of this Thermo Control Valve in the 2019-2021 cars as listed in Subaru Technical Bulletin [XXX] which clearly states that there is a redesigned TCV that replaces the defective earlier part and fixes the earlier design flaws of the one installed in 2019-2021 vehicles. I spoke with the Subaru of America Client Advocacy representative, and he was adamant that the salvage title negates any responsibility for Subaru to fix this know defectively designed Thermo Control Valve. My thinking is that the defective TCV is both a drivability and a safety issue, and due to the wide-spread early life failure of this part, Subaru should be compelled by a recall to replace the defective car in all customer cars. All ADAS is affected by a bad TCV. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORM

Filed Sep 17, 2023 · Electrical, Engine · WV

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.

Filed May 10, 2023 · MA

While at a red light, and with foot firmly on brake pedal, the car suddenly began to rev and lurched forward. All the dash indicator lights (Brake, Engine, Lane Departure, etc.) lit up. I was able to keep the car from hitting the vehicle in front of me and managed to put the car in "park" until the light turned green, at which point I put the car back in "drive," pulled into USPS parking lot, collected myself, then drove to my local mechanic (~.25 miles). Braking to turn into mechanic's location the vehicle again revved and was difficult to slow, but I managed to do so, park, and left for them to examine. Later, and on local mechanic's advice, drove (without incident) to Subaru dealer in Milford, NH to drop off for them to investigate amid recent trend in unanticipated acceleration problem and pending class action lawsuit.

Filed May 6, 2023 · Driver assistance · WI

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

Filed Jun 1, 2022 · Driver assistance · NV

The lane assistance feature almost made me hit a semi truck that had drifted over its lane. I moved to the left to allow for space, the lane assist function tried to turn me back into the semi truck I was driving over the lane to avoid. It failed to recognize a major hazard and in fact created a more dangerous situation for me. I had to jerk the wheel back to the left, fortunately it shut off and I was able to maintain control.

Filed Apr 27, 2022 · Driver assistance · IN

On average about twice per month, the touch screen will lock up. This causes the entire system to crash turning off cruise control, emergency braking, lane departure, lane keep assist, and almost every other "smart" function of the vehicle. There is no specific action that causes this, it is purely random. The "lock-up" can last anywhere from 30 seconds to several minutes. The dash notifications telling you that all of the assistance features have turned off don't come on until the system has rebooted, even though they stopped functioning at the same time the "lock-up" started. On a typical day, there is a significant delay in controlling these features via the touch screen. Minor issues where the assistance features are delayed by several seconds have happened often, but this does not result in a complete system reboot. The best way I can describe it is as if the vehicle is controlled by a computer running Windows Vista with so many viruses it can barely function. Even just adjusting the electric seats or stereo volume can have up to a 30-second delay from user input to the system response. I have noticed that during these delays, the assistance features (like lane keep and collision warning) are also delayed.