2023 model year · 0+ owner reports · Updated April 2026
According to Au7o's analysis of 0+ owner reports, the 2023 Subaru Legacy has 5 documented known issues, with 1 rated critical. The most serious is Thermo Control Valve Failure Causing Check Engine Light, Poor Heater Performance, and Possible Overheating ($1,200-$2,200 repair). Across all issues, repair costs range from $0 to $2,200. DIY maintenance guides at au7o.io.
On the 2021-2024 Subaru Legacy 2.5L FB25, multiple owners of 7th-generation Legacy models have reported failure of the electronically controlled thermo control valve used in the FB25 cooling system. When the valve sticks or its internal position sensor fails, the car may illuminate the check engine light, lose cabin heat, run the radiator fans excessively, and in some cases overheat or enter a reduced-power mode. Subaru issued service information and the problem is widely documented across Subaru owner communities and complaint databases for this platform.
Diagnosis typically starts with scanning for cooling-system related DTCs and confirming abnormal coolant temperature behavior or heater output. The standard repair is replacement of the thermo control valve assembly, followed by coolant refill/bleed and verification of proper warm-up and fan operation. If overheating occurred, the cooling system should also be checked for secondary damage and trapped air.
Parts and tips from 0+ owners who fixed this issue
On the 2021-2024 Subaru Legacy, a well-documented issue on late-model Subaru vehicles including the Legacy involves parasitic battery drain tied to the Data Communication Module (DCM), telematics hardware, or related control modules not going to sleep properly. Owners report dead batteries after the vehicle sits overnight or for a few days, repeated jump-starts, and battery replacements that do not permanently solve the problem. This issue is reflected in Subaru service communications, owner forum threads, and NHTSA complaints.
Diagnosis requires a proper parasitic draw test after all modules should be asleep, with attention to the DCM/telematics circuit and battery condition. Repairs may include DCM replacement, software updates, battery replacement if damaged by repeated deep discharge, and verification that quiescent current drops to specification. Some vehicles also need charging-system and ground checks to rule out secondary causes.
Parts and tips from 0+ owners who fixed this issue
On the 2021-2024 Subaru Legacy, the large center touchscreen used in the current Legacy has generated many owner complaints for lagging, freezing, random reboots, black screens, and unstable Apple CarPlay/Android Auto connections. In some cases climate and vehicle settings become difficult to access because many functions are integrated into the display. Subaru has released software updates and service information addressing infotainment bugs on this platform.
First verify the head unit software version and apply the latest Subaru update if available. If problems persist, technicians typically inspect USB ports/cables, perform a factory reset, and in recurring cases replace the head unit or related hardware. Intermittent failures should be documented with photos or video because some units fail sporadically.
Parts and tips from 0+ owners who fixed this issue
On the 2021-2024 Subaru Legacy, owners of 2021-2024 Legacy models frequently report windshields that crack from small stone impacts or develop long cracks quickly, often near the camera area. Because the windshield is integrated with the EyeSight driver-assistance system, replacement is more expensive than conventional glass and may require camera aiming/calibration. The issue is widely discussed in owner communities and appears in numerous NHTSA complaints for this generation.
Inspect the crack origin and determine whether repair is possible before it spreads; many cracks near the camera zone require full windshield replacement. Use OEM-quality glass when possible and ensure EyeSight static/dynamic calibration is completed after installation. If repeated breakage occurs, owners often document impact points carefully for warranty or insurance claims.
Parts and tips from 0+ owners who fixed this issue
On the 2021-2024 Subaru Legacy, owners of current-generation Legacy models have reported brake pulsation, steering wheel shake, or vibration during moderate braking, sometimes at relatively low mileage. The condition is commonly attributed to front rotor thickness variation or uneven pad deposits rather than a hydraulic failure, but it can reduce braking smoothness and owner confidence. Reports appear in owner forums and complaint databases for this generation.
Road-test the vehicle to confirm pulsation, then measure rotor runout and thickness variation. Repair usually involves resurfacing or replacing front rotors and pads, cleaning hub mating surfaces, and properly torquing wheel fasteners to prevent recurrence. If the vehicle is driven gently or sits often, a bedding procedure after repair can help reduce uneven deposits.
Parts and tips from 0+ owners who fixed this issue
POWER TRAIN:AUTOMATIC TRANSMISSION:PARK/NEUTRAL START INTERLOCK SWITCH
Subaru of America, Inc. is recalling certain model year 2021 Crosstrek, 2022 Forester, 2021-2023 Legacy, and Outback vehicles. An insufficient weld may allow water to enter the inhibitor switch, causing it to fail.
AIR BAGS:SENSOR:OCCUPANT CLASSIFICATION:FRONT PASSENGER
Subaru of America, Inc. (Subaru) is recalling certain 2020-2022 Outback and Legacy vehicles. A capacitor in the sensors for the Occupant Detection System (ODS) may crack and short circuit, which can prevent the front passenger air bag from deploying in a crash.
POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM)
Subaru of America, Inc. (Subaru) is recalling certain 2020-2021 Outback and Legacy vehicles. A programming error in the Transmission Control Unit (TCU) may allow the clutch to engage before the drive chain is completely clamped.
POWER TRAIN:DRIVELINE:DRIVESHAFT
Subaru of America, Inc. (Subaru) is recalling certain 2023 Outback, Legacy, Ascent, and Impreza vehicles. The center support bolts for the driveshaft may loosen, resulting in the disconnection of the front end of the driveshaft.
Enter your VIN at NHTSA.gov to check recalls specific to your vehicle.
Don't see your problem? Describe your symptoms to get a diagnosis, or get a full repair guide.
According to Au7o's analysis of 0+ owner reports, the 2023-2023 Subaru Legacy has 5 documented issues. The most frequently reported are: Thermo Control Valve Failure Causing Check Engine Light, Poor Heater Performance, and Possible Overheating, Battery Drain and No-Start from DCM/Telematics Module Staying Awake, Infotainment Head Unit Freezing, Black Screen, and CarPlay/Android Auto Connectivity Problems. Of these, 1 is rated critical and should be addressed promptly.
The 2023-2023 Subaru Legacy has 5 known issues documented across 0+ owner reports. 1 issue is rated critical: Thermo Control Valve Failure Causing Check Engine Light, Poor Heater Performance, and Possible Overheating. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.
Repair costs for known Subaru Legacy issues range from $0 to $2,200, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, Thermo Control Valve Failure Causing Check Engine Light, Poor Heater Performance, and Possible Overheating, typically costs $1,200-$2,200 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.
Multiple owners of 7th-generation Legacy models have reported failure of the electronically controlled thermo control valve used in the FB25 cooling system. When the valve sticks or its internal position sensor fails, the car may illuminate the check engine light, lose cabin heat… Repairs typically run $1,200-$2,200. Severity: high.
A well-documented issue on late-model Subaru vehicles including the Legacy involves parasitic battery drain tied to the Data Communication Module (DCM), telematics hardware, or related control modules not going to sleep properly. Owners report dead batteries after the vehicle sit… Repairs typically run $250-$1,200. Severity: medium.
The large center touchscreen used in the current Legacy has generated many owner complaints for lagging, freezing, random reboots, black screens, and unstable Apple CarPlay/Android Auto connections. In some cases climate and vehicle settings become difficult to access because man… Repairs typically run $0-$1,800. Severity: medium.
Owners of 2021-2024 Legacy models frequently report windshields that crack from small stone impacts or develop long cracks quickly, often near the camera area. Because the windshield is integrated with the EyeSight driver-assistance system, replacement is more expensive than conv… Repairs typically run $900-$1,800. Severity: medium.
Owners of current-generation Legacy models have reported brake pulsation, steering wheel shake, or vibration during moderate braking, sometimes at relatively low mileage. The condition is commonly attributed to front rotor thickness variation or uneven pad deposits rather than a… Repairs typically run $350-$900. Severity: medium.
Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.
