2021 Subaru Forester electrical problems

Filed Nov 1, 2026 · Electrical, Engine · TX

When coming to a stop, the auto start/stop system shuts the engine off and it fails to restart. All dashboard warning lights illuminate. The vehicle must be shifted to Park and restarted manually with the start button. The component that failed is the auto start/stop system; the exact cause is UNKNOWN. The vehicle is available for inspection upon request. This put safety at risk because the vehicle was left immobile in live traffic at stops until it could be restarted. There were no warning lamps or symptoms before the failure; the warning lights come on when the failure occurs. The vehicle was inspected by Gillman Subaru Southwest on October 229, 2026, and the dealer stated the battery performance was bad and in critical condition.

Filed Oct 25, 2026 · Electrical, Engine · RI

I was stopped at a red light. When the light changed to green I put my foot on the gas and the car totally stalled out. There were no lights, fans or radio on just total silence. I tried to restart the car putting it is park and depressing the brake while pushing the start button and nothing. It didn't even try to turn over. silent, dead. I tried several times with no luck. I got out of the car to signal to the bus and row of cars behind me to pass me. I got back into the car and tried to start it again and this time it started. I drove immediately to the mechanic near my house. They couldn't see what was going on without me leaving the car next week. The battery had been replaced 6 months ago. This was a busy intersection and I was worried about getting out of the car but I had no choice.

Filed Jul 7, 2026 · Electrical · 22,500 miles · MA

The contact owns a 2021 Subaru Forester. The contact stated that while trying to roll up vehicle windows from driver sits and passenger sit they would roll up to 3/4th all the way up and they would roll back down after. The contact stated this was a recurring event. The dealer was aware of failure and diagnosed issue needing repairs for window regulator and run channels for driver and passengers side. Manufacturer was made aware of failure and let contact know it was outside of warranty. The failure mileage was approximately 22,500.

Filed Jul 2, 2026 · Electrical, Engine · WI

My 2021 Subaru Forester has a recurring, worsening defect in the Idle Stop/Start (ISS) system that creates a stalling hazard. When ISS shuts the engine off at a stop, the engine intermittently fails to restart when I try to move again. It cranks progressively slower, warning lights illuminate, a continuous alert sounds, and the vehicle cannot proceed until I shift to Park and restart manually. This has left me immobile in live traffic at lights, stop signs, and mid-turn. The system also attempts to shut down in unfavorable moments, such as mid-turn, or as I am already releasing the brake (meaning it was depressed only lightly or briefly); it then tries to restart while still mid-shutdown, producing a pronounced shake. This is not a battery-charge problem. It has occurred even when the battery tested above its rated cold-cranking amps, and after each failure the engine restarts smoothly by manual start, indicating the starter, engine, and fuel systems function normally. I raised this before 2024, but it was not recorded until May 2024. At that visit the dealer performed the TCM reprogramming in Service Bulletin 16-147-24 (Forester, auto start/stop engine speed drop on restart) plus an ECM update. A later visit added another ECM update. A dealer has now identified yet another TCM reprogramming, quoted for a fee. The failure has persisted across all of these updates. Dealer staff acknowledge repeated customer complaints with these exact symptoms and say there is no known effective fix. Because ISS cannot be permanently disabled through any factory control, I must remember to disable it manually every drive to avoid a restart failure in traffic. The vehicle is available for inspection. This is an ongoing, unresolved safety defect that repeated manufacturer software remedies have failed to correct, and it can leave the vehicle disabled in live traffic.

Filed Jun 17, 2026 · Electrical · NY

Persistent Battery Drain on a 2021 Subaru Forester Limited. Problems began in year 4 of ownership (~17,000 mileage), after Subaru Starlink Subscription services expired. Red (Error) Starlink SOS indicator light was evident, where a normal light would show green. Battery would fully drain after about 3-4 days of inactivity while parked in a commercial garage. After repeated dead batteries, a jump-starter battery pack was used regularly, as well as a wall-outlet battery charger. The problem has not resolved with a new and appropriately specified AGM battery, replaced in December 2025. The only solution is to pull the engine-bay fuse #5, which disables the Data Communication Module (DCM), as well as other features (hands-free microphones and audio system). By pulling the fuse #5 consistently, the problem has ceased, even after a two-week period of no use. This provides irrefutable evidence that the DCM powered by fuse #5 is the source of the battery drain. The only resolution Subaru would offer was to insist on a dedicated diagnostic visit to a dealership, with the associated costs of hundreds of dollars to be borne by me, the customer, without a clear understanding of the costs or remedies to resolve this problem. I feel unsafe driving my vehicle for more than short trips given the risk of stranding or further electrical malfunctions that would impact critical vehicle functions or safety systems.

Filed Jun 13, 2026 · Electrical · MI

Driving along and various system warnings came on, then started losing power, then the engine died and the car was completely dead. Got a jump start and the car ran for a couple of minutes and died again. Had it towed to a repair shop and when they checked it the next morning, they couldn't find a problem and it ran great for them. I replaced the battery and alternator just to be safe because we were about to leave on a trip.

Filed Jun 3, 2026 · Electrical · FL

2021 Subaru Forester The vehicle has experienced recurring electrical and battery-related issues for several years. The original battery was replaced by the Subaru dealer with a larger-capacity battery because of repeated starting concerns. The replacement provided only temporary improvement. The vehicle continues to experience rough starting on a regular basis, even after installation of a newer aftermarket battery with a higher cold-cranking-amp rating. The current battery is approximately five months old. The most significant safety concern occurs during Auto Start-Stop operation. On multiple occasions, the engine has shut off at a stop as intended, but then failed to restart when attempting to move again. When this occurs, multiple warning lights illuminate on the dashboard and the vehicle is unable to proceed until it is shifted into Park and restarted manually. Because of this issue, I now disable the Auto Start-Stop feature on every drive to avoid a potential failure to restart while in traffic. The issue has been ongoing for years and has occurred with multiple batteries, including the dealer-installed replacement battery and a newer aftermarket battery. The dealer suggested that an aftermarket dash camera could be contributing to battery drain. The dash camera was disconnected, but the problem continued. I am concerned that failure of the vehicle to restart after Auto Start-Stop operation could leave the vehicle disabled in traffic and create a safety hazard. The condition appears to involve the vehicle’s electrical system, battery management system, charging system, Auto Start-Stop system, or a combination of those components. The vehicle is available for inspection upon request.

Filed Apr 1, 2026 · Electrical, Engine · TN

Automatic start/stop fails to turn car on - intermittent. Taken it to Subaru detailer miltiple times and paid for services to correct the issue, but the issue persists. Fist time - replaced the battery in July 2025. 2nd time, went on a ride along for 1 hour, issue did not happen, replaced spark plugs, issue persists. 3rd time, updated TCM software, issue still persists. Subaru of America is aware of the issue and have not gotten a resolution either.

Filed Feb 1, 2026 · Electrical, Engine · TX

Car drains battery. 45,000 miles and has had 3 batteries and have been told it needs another. Dealer says start stop switch, requires a battery of 750 CCA and not the Subaru recommend battery. Car will die in traffic and driver seat adjusts to different positions by itself. Told that these problems will never stop unless I get a higher rated battery than required.

Filed Nov 10, 2025 · Acceleration, Electrical · MD

My Subaru has an auto start/stop. I was at a complete stop, making a left-hand turn, and my car completely shuts off with the following message: For safety, auto restart disabled; eyesight with a \ through the words, put car in park and restart vehicle. In the time it took me to put the car in park and restart, I was almost T-bone. This was terrifying. This had happened on previous occasion in stop and go traffic which is dangerous because my car has come to a complete stop without any warning to me where the driver behind me There are no warning symbols, warning lights, or any type of signal or symptoms to notify me that my car was going to stop completely.. Typically I remove my foot from the break, the car starts and then I put my foot on the gas pedal and the car moves forward. In the situations described above the car just stopped.It just flat out stopped. There’s never been any indication or signal to indicate the car is not going to restart The retailer replaced my battery and said it should help. I called the Subaru factory rep who was of no help. She said she is not a trained technician and all that she could offer to do was to contact the retailer. The dealer was not able to reproduce the problem. The retailer replaced the battery without any response about the safety issue. I asked if Subaru had a safety board I could report this too and the factory rep said no, but she will document it and they’ll do an internal review to see if we have any other similar issues reported, however, they will not contact me because they don’t talk to the public about these issues. I told her there are hundreds of these if not, thousands concerns online stating the same issue. The rep said she would document my concern. Documentation is good if there’s a fix but I’m concerned about the unnecessary death of a driver.The retailer also advised I could do the auto start override, I’m trying to make a point of how serious of a safety issue this problem can be. Thank you!