2020 Subaru Forester

The thermo control valve malfunctioned causing the check engine light to come on which shut down all the safety features in the vehicle including the front eye sight camera, blind spot warning, the rear automatic braking, lane departure warning, adaptive cruise control, and lane keeping assistance. The check engine computer readout diagnostic trouble code was P26A5 "Engine Coolant Bypass Valve "A" Position Sensor Circuit Range/Performance". The vehicle was taken to a Subaru dealer who found the thermo valve performance was out of spec. This vehicle has not been recalled although the manufacturer replaced the part in 2021 vehicles acknowledging the valve was faulty. Because of the mileage on my vehicle, it was not covered under the warranty although many have been replaced under the manufacturer's warranty due to the failure of this valve under the 60,000 mile warranty. I believe this should be a recall item for others who experience this issue.

While I was traveling I stopped at a rest area and when I restarted my car, my panel lit up like a Christmas tree. All my safety assist systems were disabled and my check engine light came on. When I got home I had my mechanic run the codes and it came back to the thermo control valve. This happened on 8-29-2023. I researched the problem and Subaru put out a service bulletin in February 2022 but never notified me. My car is out of warranty now and am forced to drive without my safety systems because, 1- they don’t carry the part in stock and 2- the cost to repair is over $1400.00. Subaru was aware of the problem but kept it quiet. I feel this is a scam and Subaru should recall this part. I was warned that my car could die at any time. I bought it for those very safety systems as I am a senior citizen and rely on them now.

While driving, the 2020 Forester, the check engine light, collision light, eyesight function lights all went on at the same time. I brought vehicle to check diagnostics and it is showing Engine Coolant Bypass Valve "A" Control Circuit low in Power Train System. Their were no messages prior to all the lights turning on and I was able to bring into the dealer for oil change but not able to make an appointment for repair for a few days from now

Error code (P26A3?)for - Engine Coolant Bypass Valve. Causes the "Check Engine" light to come on and automatically disables ALL of the safety and collision mitigation systems. The Engine Coolant Bypass Valve failure is common and a known issue and Subaru has already updated the part on newer vehicle models. The common failure of the coolant bypass valve should not be disabling the safety features and the collision avoidance systems.

I was driving on a paved two lane rural route and hit a small bump in the road. Immediately, my check engine light came on and all the safety features turned off. Control panel showed multiple safety features off and the Sport mode indicator light blinking. My car only has 17K miles on it and I have had it just over a month. I was able to drive it safely home and when I called the dealership the next morning I was told I could continue to drive it until the service appointment six days later. When I got home, my husband checked it with his CEL reader and got the code for the temperature control valve (an issue known by Subaru). This was confirmed by the dealership and I was told after having driven it for several days that it should not be driven. The repair is being covered under the power train warranty.

The thermo control valve on my 2020 Subaru Forester is broken and needs to be replaced. I have owned the car for 2 years, am the first owner, and it has less than 19,000 miles. 90 minutes into a drive the "coolant temp low" indicator light came on. After I pulled over, turned off the engine, and turned it back on the check engine light and sport mode indicator light came on, and all ADAS were disabled. The coolant level was low so I refilled it and took it to the manufacturer the next morning. They inspected my car and confirmed it the thermo control valve was broken. It is still broken as I cannot afford the repair and it is available for inspection upon request. My safety was put at risk by not having access to the ADAS forward collision warning, emergency breaking, and lane departure.

The check engine light illuminated and the thermo control valve failed at 3 years old. The defrost and heater stopped working immediately making visibility extremely difficult . The eyesight and automatic braking system were also disabled due to the TCV issue. My Forester mpg dropped to under 20 mpg. The Subaru dealer inspected and confirmed code P26A3 and stated the thermo control valve needs to be replaced.

Was slowly pulling into a parking spot when the "Automatic Emergency Braking" and "Collision Avoidance Systems" engaged. The systems said that there was an "object detected" and slammed the car to a stop. Shut off the car and got out, there was no object. Had to disable the AEB system to pull into the parking space. Vehicle and component have not been inspected for this issue. Vehicle received regular maintenance at a shop (oil change) about 1 month ago and new tires about 1 week ago. Problem has not been confirmed.

When I was driving this car one night, every dash light was suddenly activated and remained on -- and as a result all safety features were deactivated. When I was able to do so, I touched the battery cables together to reboot the system. I had to do this 3 times over the course of 4 days. Realizing the problem was chronic, I took the car to the dealership (a 2 hour drive), where a service tech explained the problem 'was caused by a low battery.' This car is only 2 years old. A new car battery should last longer than 2 years. It thus seems to me the battery was defective or the car improperly drained it somehow. More important, there is no warning that a 'low battery' -- one which can easily start a car -- could still deactivate safety features while driving.