Car intermittently will studder and not go into first gear or go into second gear dangerously having car bog down and almost stall and then it violently downshifts having car RMP Hague go very high then slip and have no power to wheels and then a few seconds later go into second gear violently taking off again. Have tried taking issue to dealer but won’t even look unless check engine light comes on. Which it sometimes will for this issue and will shut back off before my short drive to dealership. Very frustrated especially being my first new car paying monthly to have this problem
2021 Subaru Legacy: check engine light
5 of the 32 complaints about the 2021 Subaru Legacy describe check engine light.
- owner complaints
- 5
- of this car's complaints
- 16%
- recalls
- 0
Check engine light by model year
What owners say
The contact owns a 2021 Subaru Legacy. The contact stated that while driving at various speeds during colder weather, the heater failed to operate as intended. Additionally, the Eyesight system was inoperable. The check engine and other unknown warning lights were displayed. In addition, the contact stated that the engine failed to warm up as intended after being started, and the engine temperature was 107°F, which was below the normal engine temperature of 200°F. The vehicle was taken to a local dealer, where it was diagnosed, and determined that the Thermal Control Valve needed to be replaced. The contact related the failure to Technical Service Bulletin: 09-119-24; however, the vehicle was not repaired because the vehicle had a Salvaged Title. The manufacturer was made aware of the failure. The failure mileage was approximately 60,000.
CVT Transmission Failure. Failure occurred at approximately 66,706 miles on 5/16/25. The Check Engine and AT Temp lights appeared in the instrument cluster. The driving conditions when this happened were a safety concern. First, the vehicle would crawl, shutter, and almost stall with high RPMs when attempting to climb a hill. Second, on a level surface at any given time the vehicle would not respond then lunge forward unexpectedly. The vehicle was inspected by a Subaru Dealership and the diagnosis was "Internal failure of transmission". The transmission needs to be replaced. The same driving conditions and error codes were experienced by an AAMCO Transmission repair facility. The diagnosis was codes P0843 and P0867 present prompting the transmission to be replaced. This repair was completed on 6/4/25. The failed transmission is no longer available.
Subaru has released a service bulletin regarding concerns with the Thermo Control Valve in specific vehicles. Unfortunately, individuals with vehicles bearing a rebuilt title, including myself, are required to cover expenses exceeding $2,000 out of their own pockets. Despite evidence indicating that the issue with the engine area is unrelated to the vehicle's rebuilt title, Subaru has chosen not to initiate a recall. This unequal treatment of titled vehicle owners is unjust, especially considering that these vehicles have passed all necessary local inspections and regulations to be deemed roadworthy. All vehicles falling within the designated mileage and age parameters should qualify for assistance. It is my belief that a recall must be issued, as this is a mechanical flaw present since the vehicle's initial manufacturing. In the accompanying service bulletin, Subaru acknowledges fault by stating that they have developed a more reliable and durable component. A P26A3 check engine light code.
Without any reason a random issue came up. Special feature components lit up on dashboard. Everything but “check engine lit up and the car features were disabled. Disabled items were eye sight, lane assist, ABD, electrical parking brake, hill assist, vehicle dynamics control. With all these lights on my power steering was also disabled. Took to dealer a year ago and all they did was “updated computer system. 3 months later the t started happening again but only intermittently but for past 3 days it’s been constant
Service bulletins that may apply
- This bulletin the announces diagnostic procedures and availability of new Engine Control Module (ECM)...
- This bulletin provides a step-by-step diagnostic procedure for resolving Remote Engine Start (RES)...
- This announcement provides information on an outage affecting the Subaru Select Monitor 5 application.
- In the interest of customer satisfaction, Subaru of America, Inc. (SOA) is extending the New Car Limited...
- This service bulletin outlines the diagnostic and repair procedure for white smoke emitted from the...
- This bulletin provides updated parts information and a service procedure to follow for removing...
- This bulletin outlines the diagnostic and repair procedure for white smoke emitted from the exhaust after...
- This bulletin provides a new diagnostic procedure for vehicles equipped with a Denso CP 1, 1.5 and 2.5...
Related recalls
No recalls on record for this model year.
Questions about the 2021 Subaru Legacy check engine light
Is check engine light a common problem on the 2021 Subaru Legacy?
5 of 32 owner complaints about the 2021 Subaru Legacy (16%) mention check engine light. The model year with the most reports is 2006.
Is there a recall or service bulletin for this on the 2021 Subaru Legacy?
There are 0 recalls and 76 service bulletins for the same area of the car. Check them below with your VIN.
Other symptoms on the 2021 Subaru Legacy
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