2020 Subaru Forester transmission & drivetrain problems

Related recalls

No recalls on file.

What owners say

1. Filed Sep 10, 2026MIEngineTransmission & Drivetrain

   Component/System Defect: Failed Thermo Control Valve (TCV) leading to sudden vehicle power loss / limp mode. Description of Safety Incident: While operating my vehicle at highway speeds late at night, the Thermo Control Valve (TCV) failed catastrophically without warning. The vehicle instantly experienced a massive loss of engine power and entered an aggressive "limp mode," causing a drastic, uncommanded deceleration in active traffic lanes.Due to the sudden reduction in…

   NHTSA complaint #11763453 · source
2. Filed Aug 19, 2026CAElectrical SystemEngineTransmission & Drivetrain

   This 2020 Subaru Forester has experienced repeated failures involving the Auto Start/Stop system. When stopped in traffic, the system shuts the engine off as designed, but on multiple occasions the engine has failed to restart normally when the driver needed to proceed. This has left the vehicle unable to move in active traffic and created a serious risk of collision. The failures have occurred in highly dangerous situations, including a busy [XXX], a major [XXX]…

   NHTSA complaint #11758094 · source
3. Filed Aug 26, 2024NCAcceleration & Cruise ControlTransmission & Drivetrain

   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…

   NHTSA complaint #11610988 · source
4. Filed Jun 13, 2024NCOther / UnknownAcceleration & Cruise ControlTransmission & Drivetrain

   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!

   NHTSA complaint #11594248 · source
5. Filed May 19, 2024OHDriver Assistance & Safety TechEngineTransmission & Drivetrain

   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.

   NHTSA complaint #11589544 · source
6. Filed Apr 26, 2024OHDriver Assistance & Safety TechAcceleration & Cruise ControlTransmission & Drivetrain

   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…

   NHTSA complaint #11585356 · source
7. Filed Apr 1, 2024CATransmission & Drivetrain

   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.

   NHTSA complaint #11580521 · source
8. Filed Mar 22, 2024ILElectrical SystemAcceleration & Cruise ControlTransmission & Drivetrain

   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…

   NHTSA complaint #11578808 · source
9. Filed Mar 20, 2024WATransmission & Drivetrain

   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…

   NHTSA complaint #11578588 · source
10. Filed Mar 20, 2024NYTransmission & Drivetrain

    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

    NHTSA complaint #11578566 · source
11. Filed Jan 18, 2024CAEngineTransmission & Drivetrain

    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.

    NHTSA complaint #11566342 · source
12. Filed Jan 15, 2024CADriver Assistance & Safety TechTransmission & Drivetrain

    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…

    NHTSA complaint #11565531 · source

Source: U.S. National Highway Traffic Safety Administration (NHTSA) Office of Defects Investigation public data. Complaints are submitted by owners and are not verified by NHTSA or by us; a complaint does not prove a defect exists. View this vehicle on NHTSA.gov Methodology