2020 Subaru Forester Problems and Top Issues – Is Your Car A Lemon?

Our research shows that windshield cracking, electrical system, and engine issues are among the top issues facing 2020 Forester owners

Updated on Author: Brian Jones | Reviewer: Sergei Lemberg

Considering the rave reviews the 2020 Subaru Forester has received, many owners are shocked to discover that their windshields crack spontaneously, their batteries drain for no apparent reason, and thermo control valves fail.

Click on other model years to view more problems:  2019   2021   2022   2023

Problems Summary

The single most common problem highlighted by complaints lodged with the National Highway Traffic Safety Administration (NHTSA) about the 2020 Subaru Forester relates to spontaneous cracking of windshields. With 520 complaints lodged with the NHTSA by April 1, 2024, 56% were filed as visibility or visibility/wiper problems, most of which concern windshields that have cracked, sometimes multiple times. Many of the complaints listed as being about “unknown or other” issues are also due to windshields that crack.

There are also a substantial number of engine and electrical system problems, some of which are seen as a problem that stems from both components.

The most common electrical system complaints are battery drain and premature battery failure, which is an issue owners of other Subaru models also complain about. Additionally, some owners of the plug-in hybrid report problems related to the battery and charging system.

The primary issue owners report of engines is related to the failure of the thermo control valve (TCV). This failure can cause a variety of problems, including:

  • Check engine light coming on
  • Engine overheating or running too cold
  • Loss of power
  • Stalling
  • Deactivation of safety features like EyeSight, lane departure warning, and automatic emergency braking

Other components and systems that are implicated in NHTSA complaints include airbags (with several complaints reporting injuries because the airbags did not deploy). Others include forward collision avoidance, vehicle speed control, lane departure, parking and service brakes, steering, structure, the fuel/propulsion system, exterior lighting, seats and seat belts, and tires and wheels.

2020 Subaru Forester Complaint Summary

Complaint CategoryNumber of Complaints
Unknown Or Other
Electrical System
Power Train
Forward Collision Avoidance: Automatic Emergency Braking
Forward Collision Avoidance: Warnings
Vehicle Speed Control

Windshield Cracking

While dealers tend to blame Forester owners for windshield chips and cracks, most owners are adamant that it is the glass rather than their negligence that’s to blame. In fact, many NHTSA complaints maintain that the glass is defective. Others have their own theories of why their windshields crack. For example, an owner from Georgia states that the windshield crack seemed to originate “from the inside near the heating coil.” It then spread horizontally across two-thirds of the windshield.

Additionally, there is evidence that there is a shortage of Subaru windshields, clearly because spontaneous cracking is so common. An owner from Texas filed a complaint with the NHTSA while waiting for a fourth damaged windshield to be replaced. “My last windshield replacement was the last windshield that the dealership received. The windshields seem extremely thin and sometimes no rock ding occurred but the windshield was discovered shattered in my garage. My current windshield encountered a small piece of road debris and the windshield completely shattered and glass fragments were on my dashboard. If anything contacts my current windshield I fear it will completely disintegrate and my vehicle will be left with no windshield.”

To add insult to injury, the owner had already paid for the replacement windshield even though “they have no idea when or if it may arrive.” An employee of the dealership told him that “even if they receive the Forester windshields, they may not arrive intact since they shatter and break during transport. This is EXTREMELY concerning and it (is) OBVIOUSLY a safety issue with these vehicles.”

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Recurring Problem

There is no doubt that the problem with 2020 Forester windshield cracking is a recurring one. For many owners, the problem just never goes away.

An owner from California says, “I have had three cracked windshields within 4 years of driving and 30,000 miles.”

Another owner had to replace the windshield every six to seven months because of spontaneous cracking. “In April of 2023, I filed a claim with Subaru of America and was instructed to make an insurance claim and my deductible would be reimbursed. As of December 1, 2023 my windshield has cracked yet again. I have had a windshield inspection done every time it has been replaced, (and) no defects or rock chips were identified. This will be the 6th windshield I have had replaced.”

“For the 2nd time in 5 months, my windshield has cracked (crack in excess of 6 inches) for no apparent reason,” says an owner from North Carolina

“My Subaru Forester’s windshield cracked within the first year. I now have 3 cracks in my windshield and I haven’t even had it for 2 years. I even spoke with my local Subaru dealership and they even say the windshields crack more than they should,” says an owner from Texas.

An owner from Illinois states, “I have had four cracked windshields since I took possession of the car in October 2020.”

Is the Glass Defective

An owner from Georgia, whose windshield has cracked several times, was told by a Subaru dealer that “the windshields are thinner to reduce weight for improved fuel efficiency.” Additionally, the dealer said they are “not as durable as older windshields.” After receiving a quotation to replace the cracked windshield with another original windshield, the owner states: “Why would I want an original windshield if it is not durable and prone to breaking? This is a defective product and I would think it would be replaced by the dealer at no charge with a more durable product.”

An owner from New Jersey has had three windshields crack in three years. “Either Subaru is making very thin windshield glass, or the material used is not sufficient to suppress small pebbles and causes the windshield to crack, often.” The complaint states that the most recent crack was ¼-inch long, but by the next day, “it had grown to over 2 feet. It seems to me there is a design flaw here.”

Another complaint states the windshield cracked “while driving on a one-way private road that leads to my home. I heard a loud pop and a foot-long crack instantly appeared on my driver’s side windshield. I saw no rocks, no projectiles, nothing. This was a spontaneous crack on the windshield. This car is only a year-and-a-half old with very little mileage.” The owner bought the car because of Subaru’s safety record. “Now I find out that Subaru knew they had defective windshields and did not issue recalls and/or inform their customers of this problem.”

An owner from Colorado, who has replaced the windshield once, states that it “keeps cracking as if unable to withstand regular road conditions that other vehicles/windshields for vehicles with the same capabilities.”

Warranty Claims Refused

Most owners realize that Subaru isn’t going to agree to warranty claims for cracked windshields. However, some are shocked to find out that this is the case.

My windshield cracked overnight, in my driveway, with no possibility of a person or animal being the cause. The nearest neighbor is 2 miles away. Subaru warranty denied my claim and said they saw a rock chip in the pics. The glass repair shop that submitted the claim said there was no sign of force (rock) to the windshield being the cause of the crack.

An owner from Oklahoma states that the front windshield started cracking on the passenger side in the middle of the glass. At the time the car was in a parking lot. “Subaru said they won’t pay for it even though the original warranty is still current. I had to replace (the) windshield, (for) $1,750.00.

Battery Problems

Battery drain and premature battery failure are the most common electrical system problems aired in complaints. Some owners experience the battery dying unexpectedly or needing replacement sooner than expected. Others experience chronic issues when the electrical system drains the battery much faster than it should.


An owner from Kansas states that his 2020 Forester had to be repeatedly jump-started after sitting for a period of time. Recently it has become a safety issue because the engine is designed to turn off at times to improve fuel efficiency. After research, Subaru has a known issue with the DCM (data communication module) system used to power the optional, subscription-based, Starlink system. This system uses 3G signals to provide emergency assistance. However, (the) 3G signal has been decommissioned and the system is unable to connect to a tower and never stops trying. This creates a parasitic drain on the battery that can, and has, prevented the car from being able to restart from a stopped position.

Another owner reports that the electrical system failed when the Forester had approximately 45,000 miles. “We have replaced the battery and tested all components” and they operate fine. “However, overnight the battery fully drains, leaving us with no vehicle again.” The owner’s husband is a mechanic, and he noticed that the last time they replaced the battery, “the dashboard was flashing and going haywire” until he removed the battery. His belief is that if he hadn’t removed the battery this would have resulted in an electrical fire.

An owner from Iowa had a chronic problem with the battery, which deactivated all the Forester’s safety features. He had to “touch the battery cables together to reboot the system. I had to do this 3 times over the course of 4 days.” The service technician explained the problem was caused by a low battery. But, says the owner, “This car is only 2 years old. A new car battery should last longer than 2 years. It thus seems to me the battery was defective or the car improperly drained it somehow.”

Thermo Control Valve Issues

Many owners complain about problems related to the thermo control valve (TCV). A faulty TCV can cause the engine to run rough, hesitate during acceleration, or illuminate the check engine light. Many complaints mention that the TCV failures happen at a relatively low mileage (under 50,000 miles) and can be expensive to repair. Some owners report that Subaru is aware of this issue and has redesigned the TCV, but hasn’t issued a recall.

An owner from Minnesota was traveling on a cross-country trip when they found themselves stranded on the side of the highway because the TCV was defective. “The check engine light was on, and other safety features were lit up on the dash as disabled (EyeSight technology, Lane Assist, automatic vehicle collision braking). The heat would not work after this incident.”

They managed to get to an auto parts store and had the vehicle scanned to determine the error code. “Checking online, we discovered that a thermo control valve replacement was needed ASAP and to continue driving the vehicle could risk severe engine damage. Since it was a Sunday, we were essentially stranded if we couldn’t use the vehicle. “ So, they kept on driving. The next Monday, they had the TCV replaced at a cost of $1,961.51. “We were told that this wasn’t under warranty due to the mileage on the vehicle (76,358 miles).”

A complaint from an owner in South Carolina describes a 2020 Forester catching alight, engulfed in flames, and destroyed within three minutes, soon after the TCV had been replaced under warranty. His daughter was driving at the time, and was “completely traumatized.” Subaru was unable to say why the car caught on fire. However, it is well known that failure of the TCV can cause a fire.

Airbag Malfunctions

While the volume of airbag complaints isn’t great (just nine out of 52), the severity of experiences warrants us looking at them. Here are five examples of complaints.

An owner from Virginia had a head-on collision with another vehicle that ran a stoplight. No airbags were deployed, and she sustained lacerations. Her husband was taken to a hospital for his injuries.

The driver of a 2020 Forester from North Carolina choked while drinking a cold beverage, became disorientated, and lost consciousness for a moment. The vehicle veered off the street and struck a tree causing extensive front-end damage. None of the airbags deployed. The driver’s injuries included a possible fractured wrist, contusions, and much pain in the neck, chest, and back areas. She was transported by EMS to the hospital.

The driver of a 2020 Forester “was pressing the brake pedal and attempting to park the vehicle suddenly experienced unintended acceleration and crashed into a brick building. During the crash, the front end of the vehicle sustained severe damage but the airbags did not deploy.” She suffered head and body injuries and required medical treatment.

Accidents with deer are not uncommon. But just like any crash with another vehicle or a structure of some kind, we need airbags to help protect us. An owner from New York had a head-on collision with a deer. “My airbags deployed but the main windshield airbag didn’t go off.” Luckily no one was injured.

Filed as an unknown or other issue, another complaint tells how the Forester caught alight after they hit a deer head on. The airbags didn’t deploy and the car was destroyed by the fire. Fortunately, the occupants weren’t injured in this accident either.

What Can You Do?

Whether your 2020 Subaru Forester has similar issues or others that are completely different, if you think you might have a lemon on your hands, call the Lemberg Law Helpline or fill out a contact form. Auto manufacturers are frequently forced to pay cash settlements, buy back, or replace vehicles that are deemed to be lemons. And the law makes them — in this case, Subaru — pay the legal bills.

Brian Jones

About the Author:

Brian Jones spent more than 30 years working as an ASE Certified Master Tech and Parts Specialist at multiple dealerships. Brian has become an authority in the industry, traveling across the country to consult for car dealerships and contributing his expertise as a writer for several major automotive publications. In his spare time, Brian enjoys working on pickup trucks, muscle cars, Jeeps and anything related to motorsports.

See more posts from Brian Jones
  • D. S

    A couple months ago I read an article about the breaking windshields in the Foresters and Outbacks. It said that Subaru has 3-4 grades of glass available and use the cheapest, thinnest glass in the new models. I’ve had 2 windshields replaced in my 2020 Foresters which has cost me $1000 (2 $500 insurance deductibles). The article also said that the heavier glass can be requested, but Subaru says with the heavier glass the mileage is affected…fewer MPGs. Personally, I’d rather have fewer broken windshields. My previous Subaru Forester was a 2007 LL Bean addition I had for 13 years. I never had to replace a windshield even though I’d had enough small pebbles hitting the glass. I sure hope they get this problem solved soon.

  • Teri A

    I bought a new 2020 Subaru Forester in may 2020. August, 2022..check engine light came on, couldn’t drive it over 10 mph. Limped it to the dealer. It’s now almost November. Still not fixed. Like previous comments, waiting on Thermal valve and gaskets.

  • Margie C

    To Tom L. Maybe this is a huge problem with the 2020 Subaru. Our Forester has the same issue. It’s been sine July 10, 2022 and our car broke down 3 hours away from where we live. Same thing- gaskets on back order. It’s frustrating but we live in the North East and winter is coming soon. We bought this car for safety but I won’t ever feel safe in it again.

  • Tom L

    I bought a 2020 Subaru sport brand new, this year 2022 on July 2oth my check engine light came on and scared me.
    Subaru called me within 10 minutes to report the issue, they said to bring the car in when they had an opening which was July 26th. After testing all day Subaru suggested to me that they keep the car since they felt is wasn’t safe to drive, they said it was a Thermal valve issue and that the gaskets for this repair were on back order. It is now September 26th (2 months) later and Subaru still has my car and only updates me sporadically, I think Subaru of Temecula is hiding a much more serious problem
    What should I do? continue to be patient?
    They did give me a courtesy car after I waited 17 days from the day I took my Sport into the repair shop, I will continue to drive it until my car is fixed

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