Subaru Ascent won't start problems

Filed Oct 14, 2026 · Visibility · NJ

I purchased a new 2021 Subaru Ascent in XXX. In XXX, at about 36,000 miles, I discovered water leaking into the cabin through the panoramic moonroof during rain and brought it to Lynnes Subaru ([XXX]) immediately. Through repeat visits and recurrences, Lynnes failed to diagnose it, blaming clogged drains. In fall 2025 they identified it, with help from a Subaru corporate regional engineer, and performed a moonroof replacement. Because I acted quickly EACH TIME water entered, there was no odor or upholstery damage at that time. Water intrusion continued in areas not visible inside the cabin (seatbelt recess). [XXX] and SOA knew right away water was still entering the vehicle. SOA told me to work with [XXX], and [XXX] had me wait for a loaner before re-examining it, because the water was not in the main cabin, headliner, etc. For over two months they set no start date, then stopped contacting me altogether. When warm weather arrived in spring 2026, a strong mold and mildew odor developed. I brought the vehicle in, loaner or not. [XXX] cleaned the drains and returned it in under two hours with the odor and mold unchanged. I was shocked they would allow, let alone instruct me to take possession of a vehicle that was a rolling biohazard! I fought with SOA to relocate the vehicle to [XXX] Subaru, a second Subaru dealer. [XXX] confirmed the water damage, mold, and improper prior work, including rear drain hoses pinched during [XXX]' reassembly. SOA authorized a goodwill repair: a second full moonroof replacement, completed around XXX, replacing moonroof, drains, headliner and carpet. On XXX, roughly five weeks after pickup, water intrusion recurred following ordinary rain, leaking into the driver-side A-pillar, and the vehicle went back to [XXX] immediately. The mold and mildew odor has never left the vehicle. Children regularly ride in this vehicle, which is currently at the dealer. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Sep 8, 2026 · Electrical, Lights · NC

2024 Subaru Ascent – Intermittent Electrical / Ignition-Control Malfunction Vehicle: 2024 Subaru Ascent Mileage: Approximately 29,000 miles Chronology of Events August 19 Vehicle had been operating normally. First occurrence – grocery store •Returned to vehicle after shopping. •Opened rear hatch, loaded groceries and closed hatch. •Driver's door would not unlock using the key fob or by touching the keyless-access door handle. •Reopened and closed rear hatch to determine whether this would reset the condition. Driver's door still would not unlock. •Passenger door could be opened. •Used the interior passenger-door lock/unlock switch, which successfully unlocked the driver's door and the rest of the vehicle. •Entered vehicle, started it normally, drove home and parked it in the garage. Second occurrence – later the same day •Opened rear hatch, loaded items and closed hatch. •Driver's door was already unlocked; entered vehicle. •Vehicle would not start. •Pressing START/STOP produced no dashboard lights and no apparent electrical activity. •Left vehicle and went inside house for several minutes. •Upon returning, the vehicle had spontaneously entered an energized accessory/ignition state without anyone operating the START/STOP button. •Lights, ventilation fan and other accessories were operating. Engine was not running. •Vehicle would not start. •START/STOP button would not turn the electrical/accessory systems off. •Approximately 40 minutes later, the vehicle remained electrically powered and still could neither be started nor shut down. •The negative 12-volt battery terminal was disconnected as the only available means of shutting the vehicle down. The dealer been unable to assess the cause of the issue and suggested driving the vehicle until the problem reoccurs

Filed Apr 23, 2026 · Brakes, Electrical · NY

2023 Subaru Ascent, under manufacturer basic warranty. Factory OEM battery has repeatedly failed. Voltage drops below 11.5V in normal use. Three documented failures in six weeks. SAFETY INCIDENT: Vehicle died on a public street and became completely immobilized. Brake warning light activated. Vehicle would not move even after a jump start. Passengers had to exit in a live traffic lane. A second vehicle was used to transport a replacement battery. The original battery is in my possession and available for inspection. A subsequent failure occurred when the original battery was reinstalled for a manufacturer-required diagnostic. Vehicle again would not start. KNOWN DEFECT: Subaru TSB 07-213-22R (revised 03/28/24) covers the 2023-24 Ascent battery and acknowledges the factory specification as inadequate, directing dealers to replace the battery, tray, cover, and holding rod with higher-capacity parts. This TSB was not proactively applied to my vehicle. The dealer did not identify or disclose it at earlier service visits where the battery concern was reported and "could not be reproduced." No recall or proactive owner notification has been issued. Dealers are not applying the TSB preventively. A complaint is open with Subaru of America Customer Advocacy. The manufacturer has declined to reimburse the out-of-pocket emergency replacement and has required a dealer diagnostic that has been repeatedly blocked by manufacturer/dealer procedural requirements.

Filed Dec 12, 2025 · AK

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.

Filed Aug 16, 2025 · Electrical · CA

The battery is draining so quick that the car doesnt start at all. The battery drained completely in 3 days and it’s happening more often.

Filed Dec 31, 2024 · Visibility · WY

The windshield cracked with no obvious damage. The crack did not start at a chip. Cracked while not driving and no recent rock hits.

Filed Nov 30, 2023 · Electrical · IA

We purchased a used 2020 Subaru Accent from a dealership on 11/16/23. Twice since that date the car would not start due to the battery not having enough charge to start it. The dealership that we bought it from stated that prior to the sale date they had a new battery installed.

Filed Aug 10, 2023 · Electrical · WI

Rear lift gate drains battery to the point where the vehicle won't start. The tailgate will beep three times, but will not open. Within 24 hours, the battery is insufficient to start it. You have to do a manual override to open the lift gate. The battery, starter and alternator were all tested and had no issues. I have to keep a jump pack in the car as the issue has become more frequent. The local Subaru dealership in Mequon, WI said they would replace the battery, but won't replace the module identified in a technical service bulletin for no charge: This seems to be a very common problem with the MY19 Ascents.

Filed May 12, 2023 · Electrical · CA

Car was unresponsive and would not start. It was just purchased certified used on 5/8/2023. On 5/10/2023 AAA replaced the battery and on 5/12/2023 the battery died again as a result the car did not start and was unresponsive. Tailgate was beeping in both situations.

Filed Mar 14, 2023 · Electrical · NC

I parked my Ascent rear facing inside of my garage to unload my groceries. When i opened my hatch at the front button, the hatch only opened halfway. The hatch would not close with the push of the button and had to be closed manually. Once I returned to my Ascent to go somewhere, the hatch sensor beeped repeatedly, while driving, until coming to a complete stop. Once driving continued, the sensor continued beeping. This occurred with two straight vehicle drives. The entire course of the drive. I parked the Ascent in my garage and returned to the car the next morning and the Ascent would not start. AAA came to do a jumpstart with no remedy. We replaced the battery with a new, borrowed battery and the car started immediately with no beeping. We charged the old battery and replaced the new battery and the Ascent had no other issues, including easy startup and no beeping. There were no warning lights for any of the issues including the hatch or the battery.