NHTSA FEDERAL EVIDENCE AUDITAudited: 2026-08-25

2021 Subaru Ascent Common Problems & Defect Telemetry

Authoritative defect intelligence synthesized from 100 verified NHTSA owner complaints, 2 federal safety recalls, and interquartile failure mileage telemetry.

Data Grade: HIGH25 Odometer Verified EntriesMethodology
Executive AI Defect Summary

The 2021 Subaru Ascent receives a 6.2/10 MazicBay Reliability Index based on 100 verified NHTSA federal complaints and 2 safety recalls. The primary reported failure mode is Electric Power Steering Assist & Suspension Noise Reports with a median failure point at 11,668 miles (IQR: 6,11521,301 mi). Out-of-warranty repairs benchmark at $450 – $1,400 .

2021 Subaru AscentNear-Luxury2021
DLC Port: Lower driver kick panel near hood lever

*Representative vehicle platform imagery. Body styling varies across generations.

MazicBay Reliability Index
6.2 / 10

16.7 complaints / 10k sold

NHTSA Owner Complaints
100

Verified US federal records

Safety Severity Grade
Critical Risk

Crash, fire & stall audit

Federal Safety Recalls
2

2 Active / Free Remedies

Switch Ascent Model Year (2014–2025)
Defect Clustering

Top Reported Problem Clusters (7)

Ranked by NHTSA Complaint Frequency
#1 STEERING & SUSPENSIONCritical Severity67% Match Confidence

Electric Power Steering Assist & Suspension Noise Reports

33
Federal Complaints
Failure Mileage (Median):11,668 milesIQR: 6,11521,301 mi
Estimated Repair Cost:$450 – $1,400 MazicBay Repair Intelligence Model
Recall Status:Under Investigation / Recall AuditNHTSA Campaign Audit
Reported Defect Symptoms
  • Sudden loss of electric power steering assist
  • Steering wheel pull or highway wander
  • Clunking / knocking noise over bumps
Potentially Associated OBD-II Codes

Correlated via MazicBay Diagnostic Engine (not NHTSA verified fact).

Sample Verified NHTSA Evidence Records (3)
ODI #11665581 • Filed: 06/08/2025

The lane assist failed by over correcting while I have my hands on the steering wheel. It over corrects to the center lane when you are driving with normal behavior. This can cause a collision if it were to over correct while a car was there, this is also easily reproducible i...

ODI #11665178 • Filed: 06/05/2025

I have a 2021 Subaru Ascent that falls under an extended warranty regarding the windshield due to a faulty windshield. My windshield has cracked, reduce visibility, and does not allow the forward collision warning to work properly. Subaru recognizes the faulty windshield and r...

ODI #11587744 • Filed: 05/08/2024

Second time windshield has cracked, not due to rock or debris chip, but from edge of windshield and either out or up. Crack continues to spread until replaced. It is dangerous to drive 1st Incident - December 2022 , crack in middle of windshield, spreading two directions 2nd I...

#2 TRANSMISSION & DRIVETRAINMedium Severity85% Match Confidence

Transmission Hesitation, Hard Shifting & Slipping Reports

20
Federal Complaints
Failure Mileage (Median):40,000 milesIQR: 6,80046,500 mi
Estimated Repair Cost:$1,400 – $3,800 MazicBay Repair Intelligence Model
Recall Status:Out-of-Pocket / TSB RemedyNHTSA Campaign Audit
Reported Defect Symptoms
  • Hard gear shifts / delayed engagement into Drive/Reverse
  • Transmission shudder / jerking under acceleration
  • Transmission slipping between gears
Potentially Associated OBD-II Codes

Correlated via MazicBay Diagnostic Engine (not NHTSA verified fact).

Sample Verified NHTSA Evidence Records (3)
ODI #11753410 • Filed: 07/29/2026Odometer: 40,000 mi

My 2021 Subaru Ascent (40,000 miles) suffered multiple major mechanical failures that pose ongoing safety concerns: 1. Engine Oil Leak: The vehicle developed an active engine oil leak at 20,000 miles, posing a risk of fluid contacting hot exhaust/engine components under the ho...

ODI #11752723 • Filed: 07/24/2026

The contact owns a 2021 Subaru Ascent. The contact stated that while driving at an undisclosed speed, the vehicle started to stall, and the transmission failed to properly operate. The vehicle was pulled over to a nearby shop and was advised to take the vehicle back to the fac...

ODI #11731955 • Filed: 04/17/2026

I am submitting this complaint regarding a 2021 Subaru Ascent that I purchased new from Herb Gordon Subaru in Maryland. The incident occurred while driving on I-95 at approximately 75 mph with my family, including children, in the vehicle. The vehicle experienced a sudden and ...

#3 ELECTRICAL SYSTEM & BATTERYCritical Severity86% Match Confidence

Electrical Parasitic Drain, Infotainment & Harness Reports

19
Federal Complaints
Failure Mileage (Median):15,000 milesIQR: 5,00017,250 mi
Estimated Repair Cost:$280 – $850 MazicBay Repair Intelligence Model
Recall Status:Out-of-Pocket / TSB RemedyNHTSA Campaign Audit
Reported Defect Symptoms
  • Unexplained battery drain after sitting overnight
  • Infotainment display / instrument cluster blackouts
  • Accessory malfunction / alternator fault warnings
Potentially Associated OBD-II Codes

Correlated via MazicBay Diagnostic Engine (not NHTSA verified fact).

Sample Verified NHTSA Evidence Records (3)
ODI #11731955 • Filed: 04/17/2026

I am submitting this complaint regarding a 2021 Subaru Ascent that I purchased new from Herb Gordon Subaru in Maryland. The incident occurred while driving on I-95 at approximately 75 mph with my family, including children, in the vehicle. The vehicle experienced a sudden and ...

ODI #11712180 • Filed: 01/20/2026

While driving my Subaru Ascent, a check engine warning light appeared on the dashboard. Shortly afterward, I noticed smoke coming from the engine compartment. I immediately pulled over and turned the vehicle off. Within moments, flames began coming from under the hood. The fir...

ODI #11710776 • Filed: 01/13/2026

The transmission on our 2021 Subaru Ascent is slipping and failing to accelerate, RPMs reving, and every issue indicator notification light is on. We took the car to our mechanic, then to the Subaru dealership service dept for diagnosis. A full transmission replacement is requ...

#4 ENGINE & COOLINGCritical Severity83% Match Confidence

Engine Stalling, Oil Consumption & Cooling Defect Reports

15
Federal Complaints
Failure Mileage (Median):67,146 milesIQR: 53,57380,718 mi
Estimated Repair Cost:$950 – $3,200 MazicBay Repair Intelligence Model
Recall Status:Out-of-Pocket / TSB RemedyNHTSA Campaign Audit
Reported Defect Symptoms
  • Engine sudden stall / hesitation while driving
  • Abnormal oil burning / consumption
  • Check Engine Light (MIL) flashing
  • Engine overheating / coolant loss
Potentially Associated OBD-II Codes

Correlated via MazicBay Diagnostic Engine (not NHTSA verified fact).

Sample Verified NHTSA Evidence Records (3)
ODI #11753410 • Filed: 07/29/2026Odometer: 40,000 mi

My 2021 Subaru Ascent (40,000 miles) suffered multiple major mechanical failures that pose ongoing safety concerns: 1. Engine Oil Leak: The vehicle developed an active engine oil leak at 20,000 miles, posing a risk of fluid contacting hot exhaust/engine components under the ho...

ODI #11752723 • Filed: 07/24/2026

The contact owns a 2021 Subaru Ascent. The contact stated that while driving at an undisclosed speed, the vehicle started to stall, and the transmission failed to properly operate. The vehicle was pulled over to a nearby shop and was advised to take the vehicle back to the fac...

ODI #11749720 • Filed: 07/11/2026

Oil leaking from upper and lower oil pan. Oil seeping from head gasket and CVT chain pump cover. RTV sealant failure. $4800 to repair. Subaru needs to solve these oil leak issues. Leaking oil is bad for the environment and engine failure could cause accidents and injury.

#5 BRAKING SYSTEM & ABSMedium Severity78% Match Confidence

Service Brakes, ABS Actuator & Master Cylinder Reports

13
Federal Complaints
Failure Mileage (Median):7,600 milesIQR: 7,20029,273 mi
Estimated Repair Cost:$350 – $1,100 MazicBay Repair Intelligence Model
Recall Status:Out-of-Pocket / TSB RemedyNHTSA Campaign Audit
Reported Defect Symptoms
  • Spongy or hard brake pedal travel
  • ABS / Brake warning light illuminated
  • Extended stopping distance / pedal vibration
Potentially Associated OBD-II Codes

Correlated via MazicBay Diagnostic Engine (not NHTSA verified fact).

Sample Verified NHTSA Evidence Records (3)
ODI #11746580 • Filed: 06/25/2026Odometer: 94,291 mi

On May 14, 2026, while driving a 2021 Subaru Ascent (approx. 94,291 miles) on a Texas expressway at highway speed during rush hour, I experienced a sudden and significant loss of engine power. There were no warning lights, no safety system activation, and no advance indication...

ODI #11689564 • Filed: 09/24/2025

Oil leak from engine constantly from FRONT DIFFERENTIAL, rec cvt pump reseal with new trans seal, pump is leaking causing drips ; drain plug is also leaking. Need to Replace Front and rear Pads & Rotors at 35k miles which is unheard of. Accessed by suberu dealership.

ODI #11658723 • Filed: 05/03/2025

Every time I go out of park there is a massive clubking noise from under the car. It's actually a super common item with these cars I am seeing as well in other forums. I believe this could lead to sheared parking brakes in the future.

#6 AIRBAGS & SAFETY RESTRAINTSCritical Severity66% Match Confidence

Airbag Occupant Detection & Inflator Defect Reports

3
Federal Complaints
Failure Mileage (Median):30,083 milesIQR: 22,62537,542 mi
Estimated Repair Cost:$400 – $1,200 MazicBay Repair Intelligence Model
Recall Status:Under Investigation / Recall AuditNHTSA Campaign Audit
Reported Defect Symptoms
  • SRS Airbag warning lamp illuminated
  • Passenger occupant classification sensor failure
  • Seat belt retractor lockup
Potentially Associated OBD-II Codes

Correlated via MazicBay Diagnostic Engine (not NHTSA verified fact).

Sample Verified NHTSA Evidence Records (3)
ODI #11729610 • Filed: 04/07/2026Odometer: 45,000 mi

Issue 1: Complete transmission failure was diagnosed by Subaru dealer March 24, 2026 at 5 years and 6 months after purchase with an odometer reading of 45,000 miles (drive train warranty 5 yrs/60,000 miles). Had to purchase and have installed a rebuilt Subaru transmission. Fir...

ODI #11714272 • Filed: 01/29/2026Odometer: 15,166 mi

2021 Subaru Ascent (VIN#***). Water found dripping down both second row seatbelts on multiple occasions during or following heavy rain, accumulated into mold growth on the carpet in front of second row seats to the front of the 3rd row seats (cargo area dry, front footwells dr...

ODI #11580921 • Filed: 04/03/2024

The contact owns a 2021 Subaru Ascent. The contact stated that while making a left turn at approximately 5-10 MPH, another vehicle ran a red light and crashed into the front passenger's side bumper. The air bags did not deploy. The contact's chest struck the steering wheel, re...

#7 FUEL SYSTEM & INJECTIONLow Severity65% Match Confidence

Fuel Pump Pressure Loss & Fuel Delivery Defect Reports

1
Federal Complaints
Failure Mileage (Median):55,000 milesIQR: 35,00075,000 mi
Estimated Repair Cost:$650 – $1,250 MazicBay Repair Intelligence Model
Recall Status:Out-of-Pocket / TSB RemedyNHTSA Campaign Audit
Reported Defect Symptoms
  • Sudden loss of propulsion power at highway speeds
  • Extended engine cranking / failure to restart
  • Fuel odor near fuel tank / engine bay
Potentially Associated OBD-II Codes

Correlated via MazicBay Diagnostic Engine (not NHTSA verified fact).

Sample Verified NHTSA Evidence Records (1)
ODI #11442758 • Filed: 12/05/2021

Unknown. I am smelling gasoline in the cabin of the car. A LOT of fumes fill my garage when I start the car. The car sometimes accelerates when I put it in park, resulting in more fumes. Fuel efficiency is lower than expected as well.

Safety Enforcement

Official NHTSA Safety Recalls (2)

100% Free Dealer Repair
NHTSA Campaign #22V907000Reported: 08/12/2022

ELECTRICAL SYSTEM:WIRING:INTERIOR/UNDER DASH

Summary: Subaru of America, Inc. (Subaru) is recalling certain 2019-2022 Ascent vehicles. The ground bolt that secures the ground terminal of the Positive Temperature Coefficient (PTC) heater may have been improperly fastened, which could result in melting of the ground terminal and surrounding components.

Safety Consequence: A melting ground terminal increases the risk of a fire.
Manufacturer Remedy: Owners are advised to park their vehicle away from structures and to avoid leaving the vehicle unattended while the engine is running. An owner who notices or smells smoke coming from the dash or driver's footwell area should immediately stop operating the vehicle and turn the ignition switch to the "Off" position. Dealers will replace the PTC heater ground bolts and if necessary, replace the ground wire and the connector holder, free of charge. Owner notification letters are expected to be mailed February 6, 2023. Owners may contact Subaru's customer service at 1-844-373-6614. Subaru's number for this recall is WRL-22.
NHTSA Campaign #26V436000Reported: 07/07/2026

EQUIPMENT:OTHER:LABELS

Summary: Subaru of America, Inc. (Subaru) is recalling certain 2026 Crosstrek Hybrid, 2025-2026 Forester Hybrid, Forester, and 2019-2026 Ascent vehicles. These vehicles were manufactured with an incorrect Gross Axle Weight Rating (GAWR) on the certification label. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) 110, "Tire selection and rims."

Safety Consequence: An incorrect GAWR label may lead to an overloaded vehicle, increasing the risk of a crash.
Manufacturer Remedy: Subaru will mail a new certification label to owners, free of charge. Owners may also choose to have a dealer install the new label, free of charge. Letters informing owners of the safety risk are expected to be mailed August 25, 2026. Additional letters will be mailed once the remedy is available. Owners may contact Subaru customer service at 1-844-373-6614. Subaru's number for this recall is WRH-26.

Pre-Purchase Inspection Checklist for 2021 Subaru Ascent

Before purchasing a used 2021 Subaru Ascent, perform the following targeted inspections based on reported federal defect patterns:

1. Cold Start & Idle Diagnostics

Scan the OBD-II port under the dash for pending freeze-frame codes (e.g. P0300 misfires, P0087 fuel rail pressure, P0420 catalytic efficiency).

2. Transmission Shift Quality Audit

Test vehicle at low-speed stop-and-go and highway merges. Check for delayed reverse engagement or gear shift shudder between 2nd and 3rd gears.

3. Federal Recall Completion Check

Verify that all 2 NHTSA safety recall campaigns have been performed by an authorized dealership using the VIN.

4. Electrical & Infotainment Drain Check

Ensure the instrument cluster, center screen, and auxiliary charging ports operate with stable 12.0V–14.4V alternator voltage.

Frequently Answered Questions

Defect & Reliability Q&A: 2021 Subaru Ascent

Is the 2021 Subaru Ascent a reliable used car?

The 2021 Subaru Ascent earns a 6.2/10 MazicBay Reliability Index based on 100 federal owner reports. Vehicles maintained under factory service schedules exhibit strong longevity past 150,000 miles.

What is the most frequent defect reported on the 2021 Subaru Ascent?

The leading complaint category is Electric Power Steering Assist & Suspension Noise Reports, with a median failure point around 11,668 miles (IQR: 6,11521,301 mi).

Are there free recall repairs available for the 2021 Subaru Ascent?

Yes, the NHTSA records 2 safety recall campaign(s) for this model year. All safety recalls are performed 100% free of charge by authorized franchise dealerships regardless of vehicle warranty status.