2020 Subaru Ascent

I am submitting this complaint regarding a known exhaust manifold/flex pipe failure affecting my 2020 Subaru Ascent Touring (VIN: [XXX] ). My vehicle was diagnosed by a Subaru dealership with a “broken flex pipe on the header” causing excessive exhaust noise and exhaust leak concerns. Repair estimate was slightly over $2,000. After researching the issue, I discovered numerous reports from other Subaru Ascent owners describing identical failures involving cracked exhaust manifold welds and failed flex pipe sections. Subaru has also issued TSB 09-106-23 involving exhaust manifold weld cracking and redesigned replacement components for this issue. Symptoms began in the low 70,000-mile range and progressively worsened before formal diagnosis at approximately 83,000 miles. This appears to be a widespread defect involving emissions/exhaust components. Many owners online report loud cold-start exhaust noise, cracked manifold welds, failed flex pipe sections, exhaust fumes/smells, and expensive manifold replacement repairs. My concern is both the widespread nature of the defect and Subaru’s handling of complaints regarding the issue. Initially, Subaru denied assistance because the vehicle has a branded title. After documentation was provided showing federally mandated emissions-related coverage/extensions were active for this VIN regardless of title status, the denial basis changed to mileage. After explaining symptoms began prior to the mileage threshold, Subaru then cited lack of dealership service history after my ownership despite the vehicle being regularly maintained by a local mechanic. I am requesting NHTSA review whether this exhaust manifold/flex pipe defect represents a broader reliability and emissions-related defect trend affecting Subaru Ascent vehicles. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Water intrusion occurred inside the vehicle, resulting in extensive mold contamination throughout the interior, including the seats, front and rear carpets, and a child’s car seat. The source of the water intrusion has not been identified. The vehicle was taken to an authorized Subaru retailer, which confirmed in writing that water was present inside the vehicle and that mold was covering interior surfaces, including the child’s car seat. The only diagnostic test performed was a car wash to check for a sunroof leak, which did not replicate the issue. The retailer indicated that further diagnostic work would require significant interior disassembly and cleaning at the owner’s expense before the source of the leak can be determined. The manufacturer was contacted regarding this issue and declined assistance, citing “lack of required maintenance.” The specific maintenance and its relationship to the water intrusion have not been identified, and the source of the leak has not yet been diagnosed. The retailer also stated that technicians would not enter the vehicle due to the extent of the mold contamination. As a result, standard recall repairs have not been performed while the vehicle remains in this condition. A dealership technician also documented in a recorded inspection that water was present beneath the carpet, that the source of the leak could not be identified without further disassembly, and that the extent of mold contamination created an unsafe working environment. This condition creates a potential health and safety concern due to mold exposure inside the passenger cabin, particularly for a child occupant. In addition, excessive interior moisture has caused window fogging, which may impair visibility while driving. No warning lights or prior indicators were observed before the issue was discovered. The problem has been confirmed by a Subaru retailer. The vehicle remains available for inspection.

Although the NHTSA form does not include a transmission category, this complaint concerns a critical transmission-related defect in my 2020 Subaru Ascent, which caused oil migration into the wiring harness and contamination of the Engine Control Module (ECM). This complaint concerns a critical transmission-related defect in my 2020 Subaru Ascent. The vehicle has been inoperable since June 2025 due to a failure of the transmission secondary pressure sensor. This failure caused oil to migrate into the wiring harness and ultimately contaminated the Engine Control Module (ECM), rendering the vehicle undrivable. Authorized Subaru dealership Huberger Subaru in Colorado Springs documented the following: - Replacement of the transmission secondary pressure sensor - Replacement of the engine wiring harness - Check engine light returned after repair - Confirmed oil contamination of the ECM Despite repeated repairs and part replacements, the vehicle remains out of service for over seven months, with no confirmed timeline for resolution. Subaru of America has not provided meaningful updates or a clear repair plan, and corporate representatives have failed to respond to emails and phone calls. The extended downtime and lack of repair constitute a safety concern, as the vehicle could fail while in use under certain conditions. Additionally, $400 was improperly withdrawn from my account in July 2025 for rental reimbursement during the warranty repair period and has not been refunded. I am seeking prompt resolution, including repair or replacement of the vehicle, reimbursement for the rental charge, and any appropriate actions from Subaru to address this safety-related defect.

Vehicle: 2020 Subaru Ascent Issue: Cold weather software glitch If you are operating an Ascent or possibly other Subarus with the CVT in temperatures below -20F be certain to have either a small wrench or the appropriate size socket to loosen the ground clamp on the battery ground cable with you so you can employ what I call the magic Windows fix wherin one completely de-powers the system and reboots it. With all the ridiculous interconnections, if the CVT temperature sensor thinks the tranny is too cold the cars operating system looses it mind and goes completely bonkers. Subaru obviously did no cold weather testing. We have had 2 failures in cold weather. It only happens at temperatures well below the-20F range. The first case happened last year while driving after being stopped for a couple of hours. Everything seemed normal and then suddenly several warning lights came on and all of the safety systems and the eyesight system shut down. The car ran and drove, but none of the associated systems would work. No traction control. No cruise control. Several other systems. The only solution was to disconnect the battery and get this rolling computer to reboot. This was a temporary fix as the condition repeated itself although the car was driveable but with none of the safety systems operational. This year we were out in cold weather, -25 to -32. We went to a place to have lunch and when I went to restart the car the app failed to do so. So I put on all my gear and went out to start it manually. It would not start and all the warning lights were on and the radiator fan was running full tilt at -25F with the car off. I tried twice to get it going by pulling the battery cable to get it to reboot. Evidently when this happens you must leave the battery disconnected long enough (about 5 minutes) for all the capacitors in the electronics to drain. Once restarted, the car drove normally but we did not shut it down for any reason for the rest of the day.

There is a significant crack in the inside rear panel of my panoramic sunroof, and no apparent or visible point of impact. The crack is spreading and needs to be replaced or I fear the glass will shatter. There is no evidence of the crack on the exterior, only on the interior. Car is out of warranty but only has 23K miles and is 4 years old. Took the car to the dealership, and they wanted to charge $4000 to fix. Contacted Subaru of America and they refused to fix. Have been on many Ascent/Subaru forums online and it appears there are multiple complaints about these cracks.

Possible Transmission issue. The transmission was replaced in February by University Subaru in Columbia, Missouri. I have made a second appointment as the vehicle is still having the same issue shifting gears or going uphill. During a drive where there was a small incline of 10 degrees when the vehicle somewhat jumped or as if it skipped a beat. I had stopped in traffic and when the other cars started to move, I started to drive forward, and the car jumped. A gap in the acceleration. I am scheduled to take it in on the [XXX] of April. I will follow-up with you. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)