2020 Subaru Ascent: check engine light

Filed Aug 20, 2026 · Transmission · CO

1. The vehicle is experiencing a transmission malfunction/failure. The dealership was able to replicate the issue and confirm the malfunction, which caused the check engine light to illuminate. The vehicle is currently being evaluated by the dealership, and any failed components should be available for inspection upon request while the vehicle remains in their possession. 2.The transmission malfunction is affecting the vehicle's ability to accelerate, maintain speed, and operate predictably. This creates a potential safety risk when the vehicle loses power or experiences unexpected changes in operation while driving, particularly in traffic or at highway speeds. The concern is heightened because transmission failure can leave the vehicle unable to safely continue operating and can cause collisions with other vehicles on the road. 3.Yes. The dealership was able to reproduce the issue, which caused the check engine light to illuminate and confirmed that there is an active problem requiring further diagnosis/repair. 4.The vehicle has been inspected and evaluated by the Subaru dealership/service center. To my knowledge, it has not been inspected by police or insurance representatives. Subaru of America has reviewed my case and the repair history but has declined assistance with the repair or to open a case. 5.Yes. The dealership was able to reproduce the issue, which caused the check engine light to illuminate. The transmission problem was also associated with operation that prompted me to have the vehicle inspected. The check engine light illuminated when the dealership replicated the condition. This current transmission is a replacement transmission done by Subaru do to a previous recall of the same issue. The current transmission only has 83,000 miles on it.

Filed Apr 20, 2026 · Fuel system, Transmission · DC

My 2020 Subaru Ascent struggles to retain power when accelerating, especially from stopping and especially when the fuel is low. The vehicle stalls or loses some power when trying to accelerate. The check engine light is not on and there is no other indication that there is a problem with the vehicle. I have discussed it thoroughly with my mechanic and we both think it sounds like a fuel pump issue. He looked at the other Subaru recalls and thinks my vehicle should be included in the other Subaru fuel pump recall (the federal safety agency ID Number: 21V587000). Does my vehicle qualify for this fuel pump recall? Thank you.

Filed Mar 25, 2026 · Driver assistance, Engine · MN

I was driving and I got check engine light and all safety features disabled while I was in the freeway, luckily I was able to drive to nearby Subaru dealer for inspection and I found out that there was a recall on the engine for this vehicle and when I contacted the manufacturer they asked me to take it for diagnostics and I did that at a Subaru retailer, but the case manager told me that this recall is being completed for the previous owner of the vehicle and cannot help me with anything, which was never disclosed when I was buying the vehicle.

Filed Mar 10, 2026 · Transmission · NV

Vehicle: 2020 Subaru Ascent (Build Date: March 2020) Component: Power Train – Automatic Transmission – Hydraulic Pressure Sensor / Wiring Harness The vehicle developed a flashing "Transmission Service" warning and check engine light. It was inspected by a certified technician at Lithia Reno Subaru. Diagnostic scan identified multiple transmission-related codes including P0137, P0700, P2096, P1867, P0867, P2723, and P0841. The technician documented the root cause as: "Found pressure sensor leaking oil through all harnesses." According to the dealership diagnosis, the transmission hydraulic pressure sensor failed and allowed transmission fluid to migrate into the vehicle's electrical wiring harness system. Fluid traveled through the transmission harness and continued into the bulkhead and engine harnesses, contaminating multiple electrical systems. Due to the extent of contamination, the dealership determined that all three harnesses must be replaced. The repair estimate is approximately $8,933. Transmission fluid entering the wiring harness can disrupt communication between the transmission control system and other powertrain components. This electrical contamination can cause erratic transmission operation or sudden loss of propulsion while the vehicle is in motion, increasing crash risk. Subaru has issued recalls and service bulletins involving CVT transmission and hydraulic pressure sensor failures in earlier Ascent vehicles using the same drivetrain. My March 2020 vehicle appears to have experienced the same failure pattern. Despite the documented component failure and extensive wiring contamination, the manufacturer declined to fully cover the repair. I request that the federal safety agency review this failure mode to determine whether hydraulic pressure sensor seal failures allowing transmission fluid to migrate into wiring harness systems represent a broader defect affecting Subaru Ascent vehicles.

Filed Jan 28, 2026 · CO

Although the federal safety agency 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.

Filed May 2, 2025 · Transmission · UT

My 2020 Subaru Ascent experienced a sudden failure of critical safety systems due to CVT fluid leaking through the transmission pressure switch into multiple electrical components. This fluid leak damaged several wire harnesses and the Engine Control Module (ECM). The check engine light came on and all Eyesight safety features disabled. Subaru has confirmed this will cost over $9,400 to repair. This issue appears to be related to known Subaru Technical Service Bulletins, including TSB 16-103-16R and TSB 02-170-17R, and matches the description in the federal safety agency Campaign WUV-07. Subaru of America has refused to fully cover the repair, even though my car is well maintained, has only 54,000 miles, and is just 4 months outside the powertrain warranty. This is not normal wear—it’s a serious defect that causes electronic failure and disables safety systems while driving.

Filed Aug 14, 2024 · Brakes, Driver assistance · TX

Transmission failure, chugging while driving on the road then slowed down in middle of the intersection, won’t accelerate which is a unsafe situation. It says “check engine”, “break, “eyesight disabled”, “at oil temp” and “transmission”. The speed was stuck to 20mph and engine eas loud. Smelled like something was burning too

Filed Dec 15, 2023 · Transmission · NY

For the past month, the engine revs up higher than normal at slow and highway speeds. It had the feeling of the engine skipping gears and staying at to high of an RPM even with the accelerator being eased off. Initially it was brought to Subaru service dealer in November and they could not replicate the issue. On 12/13/23, it began to constantly go into very high RPMS, much more frequently then it had been, and the check engine light came on as well as a warning light for the automatic transmission oil temperature light. We brought it into the dealer and the evaluated and said the transmission is failing and said it is not safe to drive. We were given a loaner and they are in the process of submitting paperwork for a new transmission under their powertrain warranty.

Filed Aug 20, 2021 · Transmission · PA

I was crossing a four lane road going 20mph when there was a loud noise, which sounded like my transmission, then I could not accelerate my car. Thankfully I was able to coast across the road without being hit by another car to a safe parking spot. My check engine light, check transmission, and check eyesight lights all went on. (Later MySubaru only sent me an email saying my engine and eye sight lights were on). I was unable to put my car in reverse but could put it into park. My lights, radio and AC stayed on until I turned my car off. A tow truck came and towed my car to the nearest Subaru dealership (which was not my dealership since I was away on vacation). There are less than 20,000 miles on my car, my transmission failing is unacceptable and thankfully did not happen on a highway which I drive on a lot. The dealership confirmed it is indeed a transmission issue and Subaru agreed to tow it to my dealership near my house.

Filed Apr 26, 2020 · Electrical · 6,633 miles · CA

My car failed to start after it had been sitting in my garage for 3 days. Hooked battery up to a portable jumper which read battery amps at 6.7. Battery jumped without issue. Took car to dealer who kept the car for 4+days and the dealer could not recreate the problem. Dealer advised me to lock my car doors as that could help turn computers off and not drain battery. Another 2 months went by and my battery needed to be jumped at least 4 more times if it sat and wasn't driven for more then 3 days or if I forgot to lock it. Finally on the morning of 4/20/20 I went out to start the car and the battery was dead yet again. The car had been locked but not driven for 3 days. When hooked up to the portable charger, the amps read 3.6. The check engine light came on and the eye sight system was turned off per instrument panel. Jumped car and took it to dealership. Dealership kept car for 4+ days and informed me that the battery was replaced as it bad. Current mileage on car is 6633.