2019 Subaru Forester: lane keeping assist jerks the wheel

Filed Mar 7, 2025 · Airbags, Driver assistance · OK

I got in my vehicle after getting gas. I was on my way to Neosho, MO, hundreds of miles from home. Thes lights were all on and I couldn't get them to go off. I figured it was because my windshield was dirty. I turned my wipers on to find out one needed replaced. I paid $30 for 1 since I have an odd type of wipers and I had been to 3 auto stores to find it. The Eye Sight, brake, check engine, air bag, and lane assist lights never went off. Now they come on randomly and go off randomly. This causes all safety features to not work. No adaptive cruise control, nothing. I finally got them to go off somehow the day I came back home. I live nowhere near a Subaru dealer. It had no other effect on my vehicle as far as I could tell. Now when they come on. I pull over until they come back on or have to drive it home to sit.

Filed Apr 2, 2024 · Driver assistance, Electrical · RI

4/2/2024 at 5:30am my Eyesight system flashed a message in orange that the Eyesight system was off - not temporarily disabled. This is NOT due to an obstruction of the cameras by weather/glare/dirt etc. All functions controlled by Eyesight including lane departure, adaptive cruise control, and forward emergency braking, as well as reverse automatic braking are disabled by this malfunction. I removed the negative lead from my battery in an attempt to reset the system which did not clear the error. No check engine light accompanied this error and all other systems seem to be functioning normally.

Filed Mar 24, 2024 · Driver assistance, Engine · CA

Thermo control valve failure, P26A3 code, eyesight safety assistance warning light ,check engine light, pre collision braking light, lane assist light.

Filed Jan 22, 2024 · Transmission · CA

Power Control Valve malfunctioning at 26,000 miles. Causing all safety features (auto braking & lane departure) to be shut off.

Filed Nov 6, 2023 · Electrical, Transmission · WA

Defective/failed thermal control valve. Valve failed while I was driving, resulting in safety systems (e.g., lane keep assist, pre-collision braking). Looking this up, this is a known issue to Subaru.

Filed Nov 3, 2023 · Driver assistance, Engine · NY

The check engine light came on and all of the eyesight components on the car were disabled as I was traveling down the highway at 70 mph (this included the adaptive cruise control, the lane departure warning, forward collision warning, etc). In addition, the engine thermostat light came on and the heater and defroster stopped working. It was cold and rainy and the window started to fog up and I was unable to clear it without a functioning defroster. This was definitely a safety issue and I had to stop driving. The car was taken to a subaru dealer today and diagnosed with faulty thermo control valve. The technician told me the car should NOT be driven in this condition due to the problem being in the engine coolant system. This is a known issue on the 2019 Forester, and other Subaru models as well, and has a TSB originally issued in Sept 2021. (#09-80-21) My car has 70K miles and therefore is just out of the warranty period. I will have to pay over $1500 to replace this part and because it is a safety issue I have no choice but to pay for the repair. It is a part that is known to be defective and I am requesting that a recall should be issued before others are also put in potential danger and/or forced to pay large sums of money to get it fixed.

Filed Oct 25, 2023 · OH

2019 Subaru switched from a thermostat to a "Thermo Control Valve" (TCV). They eventually redesigned it in 2022 due to so many failures. Mine failed rendering the cars "eyesight", lane assist, cruise control and brake assist useless. Check engine light and oil temperature light remain on. Engine code is P26A6 and P26A5. Subaru has known about this issue for years yet charge $600 for the new "Thermo Control Valve" and $1,000 to install it. These "TCV" valves fail indiscriminately with mileage not being a factor, rather the product itself. Any search online and you will find hundreds (if not thousands) of people affected in and outside the warranty. No recall has been given.

Filed Oct 19, 2023 · MI

2019 Subaru Forester with 38,000 miles. Heat stopped working. 30 minutes later, check engine light came on. Warning on dash stating that Eyesight cannot turn on. Lane assist and adaptive cruise control will not turn on. Mechanic found it needs the Thermo Control Valve replaced or the car will have no heat and the engine can overheat. Quoted a $2,000 repair cost and 3 weeks before we can get the part.

Filed Oct 6, 2023 · Driver assistance, Engine · VA

4 days ago my Check Engine light came on. In my car, when this happens, it disables all Eyesight features - collision warning, lane departure warning, etc. Work hours being what they are, I drove home that night and back to work the next day with it on. I managed to get it scanned when it popped a code for the Coolant Bypass Valve. Searching that code online lead me to DOZENS AND DOZENS of forums, posts, stories of the same code popping up on other 2019-2020 Subaru's. They all had to take it in for a hefty repair. It also led me to a Service Bulletin issued last year, which showed that Subaru had rebuilt the TCV so it could withstand corrosion, unlike the previous version. So naturally I took it into my local dealership to have it looked at, and sure enough - the TCV needed to be replaced. WHY HASN"T THIS PART BEEN RECALLED YET??? Given there is no thermostat on my cars dash, I would have no clue whether my car was overheating due to this faulty valve, until its too late. It seems like this is a big potential safety issue that Subaru needs to address, and someone needs to force their hand.

Filed Jul 23, 2023 · Driver assistance · VA

As a result of code P26A3 (engine coolant bypass valve), the cars Eye Sight system is turned off as well as lane departure, reverse automatic braking, and pre-collision braking system. While code P26A3 may in fact refer to a serious problem with then engine, there is no reason why a safety system should be shut off!

Filed Jul 11, 2023 · Driver assistance, Engine · NY

I am writing to report a safety issue with my 2019 Subaru Forester, which I believe may affect many other Subaru vehicles as well. Specifically, I have experienced a problem with the thermo control valve, which has caused the EyeSight safety features to be disabled and potentially poses a safety risk. I first became aware of this issue when the EyeSight safety features on my vehicle were automatically disabled due to a malfunction. I brought my vehicle to a Subaru dealership for an inspection, and they determined that the thermo control valve was faulty and needed to be replaced. It was alarming to learn that many other Subaru owners had experienced the same issue, and some had even experienced engine failure as a result. The EyeSight system is a driver assistance technology developed by Subaru that uses cameras and sensors to monitor the road and surrounding environment, alerting drivers to potential hazards and providing automatic braking support if necessary. This technology has been recognized as one of the most advanced driver assistance technologies available, and is designed to help prevent accidents and reduce the severity of collisions. The EyeSight system includes features such as adaptive cruise control, pre-collision braking, lane departure warning, and sway warning, which work together to provide a comprehensive safety package for drivers and passengers. These features are critical in keeping drivers safe. I am concerned that this issue may be more widespread than initially thought, and that it may pose a safety risk to drivers and passengers of affected Subaru vehicles. The faulty thermo control valve can cause the EyeSight safety features to be disabled, which can lead to reduced safety performance, accidents, and potentially harm to drivers and passengers. Sincerely, Davide Alves

Filed Jul 5, 2023 · Driver assistance, Engine · WA

When I turn the car on it flashes check engine eyesite failure which then turns off the ability to use cruise control, crash detection, lane assist, ext. we called Dick Hannah Subaru and the code came up as P26A5 engine coolant bypass valve A position sensor. They said a thermo valve needs replaced and they’ve seen that happen a lot in 2019/2020 Subarus