2020 Subaru Forester

While accelerating to merge in the freeway the Thermo Control Valve malfunctioned, causing check engine light to come on which turned off all the safety features (lane assist off, precollision off, RAB and eyesight off) of my Subaru 2020 Forester Sport. I’ve researched the internet and shows it is a common issue. I brought it to a subaru dealership and was told it is not safe to drive the vehicle. Since I just passed 60k powertrain warranty (around 62k), it is not covered and had to pay over $3,000.

The Thermo Control Valve failed at 33,945 miles. Because of this, the heater, Eye Sight, Cruise Control, Lane Assist, and Collision Brake did not work. The engine was then only running at "Sport" mode. It did not regulate the heat to the oil and could've caused sludge. The problem was confirmed by a Subaru Dealer Service Shop. I only noticed this problem when the blue thermometer light came on the dash board. Usually I wait about 5 min and once the car is warmed up the light goes away. This time the blue thermometer warning light did not turn off and stayed on for the remainder of the trip. When the car was restarted on the same day the engine check light came on. Eye Sight, Lane assist and Collision assist lights were on.

Engine check light came on and after running a test it seemed as though the thermo control valve thermostat was not working properly which means the valve that lets coolant into the engine doesn't know what the temp is and when to release coolant. That ended up being the issue and we were barely under the 60k mile warranty for the powertrain so it was covered but I've been reading that it is a common issue and others are surprised it hadn't been recalled yet as it could cause the engine to overheat. The part is so defective that subaru has already designed a better part which means they know its a common issue.

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. The valve was replaced. 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. Through a "Goodwill gesture" Subaru replaced the part in my car at no cost. I believe this should be a recall item for others who experience this issue.

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

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.