2020 Subaru Forester Powertrain & Transmission Problems

Subaru of America is aware of the problem which impacts several models and model years, see Subaru Service Bulletin 16-132-20R. Transmission slippage and bounce feel during acceleration. Can be strong enough at times to visually see occupants moving with momentum/bounce at times. Could contribute to vehicle not maintaining/reducing/responding to speed control systems, failure of transmission components, stranding occupants, and other similar hazards that come with the mechanical failure of a transmission. Has caused slowing of acceleration which impacted surrounding traffic on a few occasions. Vehicle is scheduled to be inspected by manufacture dealership on morning of 08/27/24.

CHECK ENGINE, FORWARD COLLISION WARNING, FLASHING "S"DRIVE, NO EYESIGHT, AUTOMATIC EMERGENCY BRAKING WARNING LIGHTS, ALL CAME ON AT ONCE AND STAYING ON. POSSIBLE THERMO CONTROL VALVE ISSUE - NEEDS A RECALL!

2020 SUBARU FORESTER JUST HAD A CHECK ENGINE LIGHT APPEAR. THE ENGINE MALFUNCTION CODE IS P26A3, WHICH IS A DEFECTIVE THERMOSTATIC CONTROL VALVE. THIS MALFUNCTION ALSO AFFECTS THE VEHICLE MANUFACTURERS ADVANCED DRIVER ASSITANCE SYSTEMS SUCH AS: "EYESIGHT" BLIND SPOT MONITORING, LANE KEEP ASSIST, ETC. VEHICLE ONLY HAS 51,000 MILES ON IT.

I purchased a 2020 Subaru Forester in 2020. Last week, the Check Engine light came on and it was due to the thermo control valve that need replaced. My car was outside of warranty at 70k miles and Subaru’s customer advocacy office will not reimburse despite this being a faulty defect for many 2018-21 Foresters. There is a class action lawsuit filed but I’m still out $1900. There should be a recall and I should not be paying for this manufacturer defect.

Thermo control sensor failed which will damage the motor if overheating dealer says it's going to cost me $1500 and it isn't covered under drivetrain warranty which is 5 years 60000 miles I have 27000 miles

The thermo control valve failed causing the coolant to run at full and not allowing the engine to reach proper temperature and the heating system to not provide heat, also it caused multiple safety systems to turn off including eye sight, emergency braking, rear auto brake, lane keeping, adaptive cruise control, traction control. the failure of this unit is a known issue to Subaru per their own service bulletin 09-80-21, while mine was not covered by Subaru's own warranty due to the mileage this vehicle is less than 5 years old, the repair costs will be $2000.00+ as quoted by the dealer.

The thermo control valve on vehicle failed on 2020 Subaru Forester which is causing vehicle to loose acceleration, multiple errors codes displaying on the vehicle instrument dash panel and no heat in the vehicle (see attached photo for reference). The failure of this device could cause a vehicle fire depending on what position/ and or state the thermo valve failed in. There needs to be a manufacturer recall on this particular part as there is numerous amounts of complaints and issues. Subaru needs to make it right with the customer. we need to drive safe vehicles on the road.

While driving temperature light, check engine light, all ADAS lights came on as inoperable (cameras, warning, ABS, BSD/RCTA), no heat (including defrost) available to defrost or for cabin. Appointment 3/13 replaced thermo control valve assembly , coolant bypass valve, intake gaskets, fuel line, coolant, total charges $2070. Luckily had extended warranty I bought, that I had to make a claim on. Dangerous to drive (no camera based safety features available, no defrost for the snowy weather, no emergency braking or other collision safety features on, this affected the entire 'eyesight' system). The engine also had no thermo control regulation during this time, affecting not just then, but possible future performance and early aging due to disregulation.

Got warning P2A63 that the Thermo Control Valve is shot around 63k miles. Apparently this is happening very often in Subaru's made between 2019 and 2022.

The thermo control valve (TCV) went bad at 54,000 miles. The result is that none of the safety features work anymore. Collision detection, Eye-Sight, lane change warnings, anti-skid, etc. all go offline when the TCV goes out. We can drive the car but it now has no safety features.

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.

41k miles P26A3 P26A5 ****Eyesight disabled*** ***Forward collision disabled *** Failed TCV and dealer will not cover because warranty period is over.

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.

Our thermo control valve (TCV) assembly failed and caused dangerous loss of speed and control while on the highway. Subaru is fully aware of the defect in their design as they issued a service bulletin to inform their service centers of a new, fixed TCV assembly that is retaining the same part number (a notice only sent to their service centers, NOT to owners). Please see attached. Despite being aware of the defect, Subaru has not voluntarily replaced the defective TCV assemblies or even bothered to notify owners. Instead, they are letting us put our families and other drivers in dangerous situations through sudden loss of control. There are pages and pages of other owners experiencing this dangerous issue and - like me - being surprised to find it's a known issue that Subaru is not proactively fixing (see any of the owner forums like subaruforester.org).

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.

Thermo control valve is bad. Ask subaru to issue recall on 2019-2020 models.

The thermo-valve controller gives out on this vehicle. Through searches and discussions with two separate dealerships, this seems to be an incredibly common issue. It's enough that Subaru has actually completely replaced the design of this piece for whenever it gets replaced. This triggers a check engine light which already removes many features on the Subaru. My understanding is that this part controls and measures the engine temperature which means that drivers have no clue if their engine is overheating or not when it goes out. Subaru has gotten away with covering this part over their Powertrain warranty since the vast majority of their vehicles are having this part break within 3 years. Most drivers are happy with this because the major ($1500-2000) repair is covered. The issue is that people that drive more often, like myself, are stuck footing the bill for a part that Subaru has admitted doesn't work properly just because we've now fallen out of this 60k mileage warranty. From my research, it's not a part that is greatly affected by mileage, so much as time since the dealerships have noted that every replacement they've seen has fallen within 3 years, regardless of the mileage. For that, I'm asking that there be a true recall put in place for this part. This is a major expense for almost anyone and isn't fair for Subaru to hide behind a warranty that won't apply to everyone when they know they created this improperly. Even the reps at the dealership mentioned that they see this far too often for it not to be a recall, but that most people are still under 60k miles, so there aren't normally issues.