NHTSA complaint #11451108

Owner complaint summary

Over the weekend, the check engine light came on and I lost heat in my vehicle instantly (like flipping a light switch) after already driving with full heat for about 30 minutes. In addition to losing heat on a zero degree day, the vehicle also lost the capability to circulate and redirect coolant to the engine properly, causing a significant reduction in engine temperature causing it to run nearly 100 degrees Fahrenheit less than optimal running temperature. Upon research, the only logical explanation was the failure of the "thermo control valve" which was added to the Subaru lineup starting in 2019, and this was just confirmed as the cause of this incident by the dealer. While coolant issues previously were managed easily in other vehicles, or a slow reduction in the ability of the heating system, having an electronic component control the diversion of coolant in the car for cabin heat and engine heat control seems to be harmful, not only potentially to the engine, but causing the heat to instantly stop to someone that may not be dressed to deal with it while driving in zero degree weather can cause potential significant health problems. This part should not be the sole source of control, let alone be failing without warning after a mere 3 years. In addition, a quick search online provides no information on the product, but many threads of individuals experiencing similar issues, as well as comments that Subaru has recognized it was originally inadequately built and have since produced a more Hardy product to replace them with. The other issue with this part, is that it is below the intake which needs to be removed to replace it. While the intake and other coolant system items are mentioned under warranty, this part is never mentioned. For this being a new addition starting in 2019, it is deeply concerning that there are many accounts for this, with no official messaging from Subaru, for such a critical part.