This bulletin provides guidance when diagnosing chain slip, judder, shudder, and hesitation concerns on the TR690 model CVT transmissions used in the models listed. (This is an revised version of the original bulletin.)
full bulletin at NHTSA ↗2020 Subaru Ascent powertrain problems
moderate Owners of the 2020 Subaru Ascent have filed 54 NHTSA complaints about the powertrain, typically surfacing around 25,000 miles at roughly $2,500 to repair (U.S. federal records, as of July 2026). Source: NHTSA Office of Defects Investigation. See powertrain across all vehicles →
Failure mileage
Complaints
54
Recalls
0
Avg fix
$2,500
| Model year | powertrain complaints |
|---|---|
| 2019 Ascent | 80 |
| 2020 Ascent (this page) | 54 |
| 2021 Ascent | 16 |
| 2022 Ascent | 13 |
When does it fail?
Of the 54 powertrain complaints filed for the 2020 Subaru Ascent, here's the actual mileage breakdown — failures cluster heaviest at 0-25,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
Owners have filed 54 powertrain complaints with NHTSA against this vehicle, but no formal recall covers the issue — the federal record reflects what manufacturers have admitted, not everything owners are reporting.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering powertrain on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
This Bulletin announces a correction to the diagnostic procedures for certain CVT related DTCs, including P0730, P0746, P0747, P0841, P0846, P0867, P1867, P1894, and P2723.
full bulletin at NHTSA ↗This bulletin announces a design change to the TR690 CVT control valve body which features an enhanced line pressure sensor O-ring, designed to prevent abnormal sensor readings caused by O-ring leakage.
full bulletin at NHTSA ↗In the interest of customer satisfaction, Subaru of America, Inc. (SOA) is extending the New Car Limited Powertrain Warranty coverage for the Continuously Variable Transmission (CVT) on the above listed models and model years from the original five (5) years or sixty thousand (60,000) miles (whichever comes first) to ten (10) years or one-hundred thousand (100,000) miles (whichever comes first).
full bulletin at NHTSA ↗This bulletin provides guidance when diagnosing chain slip, judder, shudder, and hesitation concerns on the TR690 model CVT transmissions used in the models listed.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Owners consistently report CVT transmission shuddering, jerking, and slipping between 20–50 mph—especially at 1500–3000 RPM. The transmission refuses to downshift properly on hills, engine hesitates during acceleration, and power loss creates real hazard when merging. Many failures occur before 20,000 miles; at least one vehicle required three separate transmission replacements within warranty. Dealerships repeatedly claim they cannot replicate the fault during five-minute test drives, yet owners feel it every drive. Subaru issued recall 21V955000 but the remedy parts are unavailable at dealers even six months to a year after notification.
Hydraulic pressure sensor seals fail, dumping transmission fluid into engine and bulkhead wiring harnesses and disabling Eyesight safety systems. Repair bills reach $9,400 when multiple harnesses need replacement. One vehicle failed at 37,000 miles, sat for 52 days at the dealership, got a complete transmission replacement—and the same symptoms came back. Subaru denies warranty coverage once mileage or time creeps past the warranty window, offering only partial goodwill payment.
Additional problems surface: oil leaks from every seal on the engine, driveshaft support bolts backing out (acknowledged in 2019 and 2022 models but not recalled for 2020), differential parts failing in batches, brakes shuddering after multiple replacements, and battery draining for no apparent reason while parked. Lane Assist activates unprompted. No warning lights alert owners until catastrophic failure is imminent—leaving drivers unsafe and unable to plan for repairs.
Same Subaru Ascent powertrain reports on nearby years: 2019 · 2021 · 2022
Failure modes owners describe
CVT Transmission Shuddering, Slipping, and Surging
The CVT transmission exhibits shuddering, lurching, slipping, jerking, and surging—especially at specific RPM ranges (1500–3000 RPM, 20–30 mph, 35–50 mph). The problem often worsens over time and recurs even after dealer attempts at reprogramming or component replacement. Owners report loss of power during acceleration and erratic gear engagement. No warning lights illuminate in many cases despite the vehicle being unsafe to drive.
When: Occurs from early ownership (600 miles, 2,800 miles) through later mileage (50,000+ miles); some failures at under 20,000 miles
Symptoms owners cite: Shuddering or vibration resembling rumble strips; Jerking and lurching during acceleration; Transmission slipping with RPM surges; Loss of power or hesitation when accelerating; Grinding or squealing noises; Inability to reach higher RPMs for highway merging; Intermittent stuttering at highway speeds; Vehicle stalling or losing motive power
Codes mentioned: P0137, P0700, P2096, P1867, P0867, P2723, P0841
Repairs/costs cited: Dealerships have attempted reprogramming, firmware updates, software reflashing, recalibration of torque converter, and replacement of transfer cases and transmissions. Multiple owners report the problem persists or recurs after repair. Transmission replacement costs range from full warranty coverage to $9,400+. Some vehicles have required transmission replacement three times within warranty period.
Recalls/TSBs owners mention: Service bulletins WRK-21 and related TSBs issued (16-103-16R, 02-170-17R). NHTSA Recall 21V955000 issued but remedy parts remain unavailable at many dealerships months after recall notification. Subaru has offered partial coverage under powertrain warranty but has refused full coverage once vehicles exceed warranty limits. Some repairs labeled 'complete' despite symptoms persisting.
Hydraulic Pressure Sensor Failure and Wiring Contamination
The transmission hydraulic pressure sensor seal fails, allowing transmission fluid to leak into electrical wiring harnesses. The fluid migrates through transmission, bulkhead, and engine harnesses, contaminating multiple electrical systems including the Engine Control Module (ECM), disabling safety features and causing erratic transmission control.
When: Early in ownership; documented at 54,000 miles and 37,000 miles
Symptoms owners cite: Flashing 'Transmission Service' warning light; Check engine light illumination; All Eyesight safety systems disabled; Erratic transmission operation; Loss of propulsion or hesitation; Multiple warning lights ('Christmas tree' dashboard)
Codes mentioned: P0137, P0700, P2096, P1867, P0867, P2723, P0841
Repairs/costs cited: Requires replacement of transmission harness, bulkhead harness, and engine harness due to extent of fluid contamination. Repair estimate approximately $8,933 to $9,400. In one case, transmission was replaced at 37,000 miles and entered dealership for 52 days; symptoms continued even after replacement.
Recalls/TSBs owners mention: Subaru has issued TSBs (16-103-16R, 02-170-17R) related to hydraulic pressure sensor failures in earlier Ascent vehicles. Recall WUV-07 addresses similar issues. Subaru has declined to fully cover repairs even for vehicles just outside warranty, offering only partial coverage on a goodwill basis.
Driveshaft Support Bracket Bolt Loosening
Bolts securing the driveshaft support bracket gradually back out due to manufacturing defect, causing the driveshaft to partially or completely disengage from the vehicle. This is a known issue affecting 2019 and 2022 model years with active Subaru service advisories, but the 2020 model year is not included in the recall despite the same failure occurring.
When: Timing unknown; failure risk increases over time and mileage
Symptoms owners cite: Driveshaft coming loose or completely disengaging; Unusual noises from undercarriage; Loss of propulsion or drivability
Repairs/costs cited: Bolt tightening or replacement required. Subaru offers 50% goodwill payment on repair costs, not recognizing it as a warranty issue for 2020 models. Repair cost varies; dealership did not check bolt torque during routine oil changes due to lack of service advisories.
Recalls/TSBs owners mention: Subaru has issued service advisories for 2019 and 2022 models but not for 2020 Ascents, despite the failure occurring in 2020 vehicles. Repair not covered under warranty; owners offered partial reimbursement only.
Engine Seal Leaks (Oil Pan, Timing Cover, Cam Carriers, Oil Cooler)
Multiple oil seals fail due to Subaru's use of RTV silicone sealant (formed-in-place gaskets) instead of traditional rubber gaskets. Leaks occur from cam carrier-to-head seals, front timing cover, upper and lower oil pans, and oil cooler. Owners report oil leaking from 'every orifice of engine,' requiring engine reseal.
When: Early in ownership; one case documented at 37,000 miles
Symptoms owners cite: Visible oil leaks from multiple sealing surfaces; Low oil levels requiring frequent top-offs; Oil odor or dripping onto driveway
Repairs/costs cited: Dealership recommended complete engine reseal due to extent of RTV sealant failure. One owner with transmission failure also documented extensive oil leaks requiring seal replacement.
Recalls/TSBs owners mention: No recall issued. No manufacturer response documented in narratives.
Recall Remedy Parts Unavailability (21V955000)
Owners received NHTSA recall notification 21V955000 (Powertrain) but the required parts for the repair were not available at dealerships. Multiple owners report being notified of the recall over 6 months to 1 year prior without any remedy being performed. Subaru has not adequately distributed parts to dealerships to support the recall.
When: Recalls issued but parts unavailable for 6 months to 1+ year after notification
Symptoms owners cite: No failures may have occurred yet, but owners unable to have recall performed; Continued vehicle use with known defect risk
Repairs/costs cited: No repair performed; parts not available. Owners continue to operate vehicles under recall notice without remedy.
Recalls/TSBs owners mention: NHTSA Campaign Number 21V955000 issued but Subaru has not supplied remedy parts to dealerships in a timely manner. No timeline provided for parts availability.
Front Strut Mount and Wheel Bearing Failure
Front wheel bearing and strut mount failure causing noise during turns and braking. Dealership initially misdiagnosed and failed to identify the bearing failure on first visit. Failure occurred at low mileage.
When: Within first 3 years of ownership; at approximately 3 years old per owner report
Symptoms owners cite: Noise when turning or slowing down; Grinding sounds from front wheel area
Repairs/costs cited: Front strut mount and bearing replacement required. Dealership did not properly diagnose on first visit; parts were repaired on second visit.
Recalls/TSBs owners mention: No manufacturer response documented.
Differential Chirping and Synchronization Loss
Primary differential produces chirping or squeaking noise indicating defective batch of parts. More critically, wheels lose synchronization during turns despite vehicle having traction control systems designed to prevent this condition.
When: Began November 2021; diagnosis and repair took approximately 3 months for parts acquisition
Symptoms owners cite: Chirping or squeaking sound from underside of vehicle; Wheels not synchronizing when turning (vehicle loses traction control function); Wobbly or unstable handling during turns
Repairs/costs cited: Primary differential requires rebuild with replacement of 21 parts total. Parts acquisition took 3 months.
Recalls/TSBs owners mention: Service department identified defective batch of parts; no recall or broader response documented.
Battery Drain (Parasitic Draw)
Battery drains rapidly when the vehicle is off and parked, without any lights left on. No warning lights or messages alert the owner. Dealership refuses to acknowledge or diagnose the problem.
When: Intermittent; battery dies after vehicle sits for several hours
Symptoms owners cite: Dead battery after short parking periods with no electrical loads; No warning messages or lights
Repairs/costs cited: Not repaired; dealership refused to acknowledge the problem.
Recalls/TSBs owners mention: Dealership denial of issue.
Automatic Braking System Malfunction (EyeSight Backup Brake)
Automatic backup braking system engages unexpectedly when backing up a trailer on an incline. The system can only be disabled through the infotainment system and re-engages immediately when the vehicle is shifted to Drive, making trailer parking impossible.
When: When towing or backing up trailers on slopes
Symptoms owners cite: Automatic braking engages when backing up on inclined surfaces; System repeatedly re-engages after being disabled; Prevents safe trailer maneuvering
Repairs/costs cited: No repair documented; system design issue with how disable feature operates.
Recalls/TSBs owners mention: No response documented.
Lane Assist System Malfunction
Lane Assist system activates unprompted while driving, pulling on the steering wheel without driver input. This creates a safety hazard by taking control of the steering.
When: Occurs intermittently during normal driving
Symptoms owners cite: Lane Assist activates without warning; Automatic steering wheel movement; Loss of driver steering control
Repairs/costs cited: Not repaired; dealership unable to diagnose.
Recalls/TSBs owners mention: No response documented.
Brake Shuddering and Squealing
Brakes shudder and produce loud squealing noises despite multiple replacements. One owner required brake service at 0 miles (before delivery), at 3,000 miles, and at 5,000 miles, yet the problem persists.
When: From very early ownership; documented at 600 miles and recurring through 5,000+ miles
Symptoms owners cite: Brake shuddering during stops; Loud squealing noise from brakes; Vibration through brake pedal
Repairs/costs cited: Brake pad and rotor replacement performed multiple times with no resolution.
Recalls/TSBs owners mention: No manufacturer response documented; dealership continued attempting repairs.
Engine Stalling (Transmission-Related)
Vehicle stalls while driving due to transmission malfunction. In one case, vehicle stalled at 55 mph with no warning lights. In another, vehicle lost all power while attempting to merge onto a highway.
When: Documented at 62,000 miles and at approximately 20,000 miles
Symptoms owners cite: Complete loss of motive power; Engine stalling without warning; No warning lights in most cases
Repairs/costs cited: Transmission repair or replacement required. One case documented transmission need to be repaired; another required transmission replacement.
Recalls/TSBs owners mention: No assistance offered in case where manufacturer was notified.
Accelerator Control Loss (Stuck Throttle)
Engine continued revving at high RPM (4500 RPM) with foot off the accelerator pedal during highway driving. Driver had to slam accelerator multiple times to regain control before toll plaza.
When: Occurred May 2022 on highway
Symptoms owners cite: Engine holding high RPM (4500) without throttle input; Loss of throttle responsiveness; Difficulty slowing vehicle
Repairs/costs cited: Field technician reset torque converter programming; issue could not be replicated by dealership for further diagnosis.
Recalls/TSBs owners mention: Subaru field technician performed torque converter programming reset. Open recall exists for transmission issue with no fix yet available.
Synthesized from 54 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 4 most recent
The contact owns a 2020 Subaru Ascent. The contact stated that while operating the vehicle, the transmission malfunctioned, and the vehicle would not properly accelerate. The vehicle was taken to the local dealer who serviced the rear differential but later the failure reoccurred. The vehicle was taken back to the local dealer to be diagnosed, and it was determined that the transmission was…
Transmission is lurching and surging when driving. Pressing gas pedal from a stop the belt continues to slip. Took it to Paul Moak Subaru they claimed to do the inspection told me they don’t do test drives for malfunction checks. They said they completed the inspection for transmission recall. The Ascent continues lurch and slip with grinding noise and loss of speed. I told them about the issues…
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…
2800 miles on vehicle. Today lost power twice going up steep hill (electrical functions still intact, was accelerating uphill and was similar to shifting into neutral then re-accelerated after 10-15 seconds, driving approx 30mph). Narrowly avoided collision due to slippery road, did briefly roll backwards before braking. Not sure I will ever be willing to put my kids back in this nearly-new…
Had powertrain trouble with your 2020 Subaru Ascent?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the powertrain problem on the 2020 Subaru Ascent?
It's a documented issue but not catastrophic. 54 complaints have been filed. Repairs average $2,500 and most owners catch it before it causes a breakdown.
At what mileage does the powertrain typically fail?
Across the 12 complaints that reported odometer mileage, most powertrain failures cluster between 5,074 and 61,900 miles, with the median around 25,000. A quarter of owners report trouble before 5,074; a quarter make it past 61,900. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
What does it cost to fix?
Independent shops typically charge around $2,500 for powertrain repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to powertrain?
No active recalls currently cover powertrain issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2020/Subaru/Ascent.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.