Subaru Forester start-stop 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 16, 2026 · Brakes, Electrical · TX

On [XXX], my [XXX] son was driving our Forester on [XXX] at [XXX]. At red light, Auto Start-Stop shut off engine as designed. On green, releasing brake triggered restart attempt. Dash lights cycled continuously, engine failed to restart. Brake pedal pushed back firmly and would not depress. Simultaneously, Electronic Parking Brake auto-engaged and would NOT disengage, preventing shift to neutral or pushing to safety. We were stranded in active lane off high-speed artery until flatbed tow arrived. Because EPB had no manual override, tow operator had to drag vehicle onto flatbed with brakes locked. Towed Sunday night to selling dealer, diagnosed Monday 7:30 AM as dead/failing 12V battery, which was replaced. CRITICAL SAFETY QUESTIONS: Why no Battery State-of-Health warning before failure? Vehicle should alert when cranking capacity degrades below safe Auto Start-Stop restart threshold. A voltage/health indicator would have prevented this. Why no emergency EPB manual override? No accessible mechanical backup to release EPB during electrical/start fault. Locking wheels in live roadway creates severe collision hazard for occupants and traffic. REQUEST: Formally document as Product Safety Concern, assign corporate case number, and escalate to engineering/product safety team for review of battery monitoring logic and EPB override design. This created unacceptable hazard for my son. We request written response. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Oct 3, 2026 · Engine, Fuel system · CA

On two separate occasions, less than one year apart after Subaru Service replaced my battery with a “larger” battery without my knowledge my vehicle suffered sudden, catastrophic electrical failure while moving in active highway traffic, causing an immediate loss of propulsion and creating a life-threatening safety hazard. This has happened two times the second time less than a year after the “larger” battery replacement. This car has less than 50,000 miles on it and has a perfect service record all done at AutoNation Subaru Carlsbad. We refuse to drive this car, even though it has been serviced and a new battery has, yet again, been installed. We have no faith in this car and are not willing to put ourselves in a life-threatening situation again. We also do not feel comfortable selling this car, even though we have received many above market offers. We do not feel that we can sell this car in good conscience to an unknowing next victim. It is unsafe to drive and can lose power at any moment while driving without any explanation given from Subaru. The first battery failure occurred prematurely in August 2025. Asked repeatedly why a car battery would fail while driving? Could not get a straight answer except that someone finally said it could possibly be from the auto stop start system The new larger battery failed less than one year later in August 2026, so it didn’t even last a year and it was larger. The service department at AutoNation Carlsbad told me my car passed all the test and I have nothing to worry about. This goes against any common sense. How could this happen 2 times where no issue has been disclosed. Both situations were extremely traumatic and dangerous and I feel lucky that I was able to come out of it. I’m not sure the next time would be the same. We are not able to drive this car because common sense tells us there is a bigger issue going on. So far we’ve communicated with Subaru of America and were denied California Lemon law without reason.

Filed Sep 13, 2026 · Driver assistance · CT

On two occasions now, one on XXX and another in XXX our vehicle initiated a pre collision breaking sequence with no visible object in our path. On XXX this occurred while turning off of a main road into a shopping center located on route XXX in [XXX]. I was traveling at about 15-20mph with no cars in front of me. The vehicle displayed a pre- collision warning and the vehicles breaks locked up. No injuries but I had both my children with me in the car and we were all quite shaken up. The event in XXX happened while my husband was traveling on climax rd in [XXX]. On a sunny day with no one ahead of him traveling at about 45mph the same pre collision warning happened and the breaks locked up on him causing his tires to scratch and the car to come to a Hault. no injuries as a result. Additionally we have had multiple failures of the auto start/stop system while in active traffic. At this point it is about 5 times. Each failure resulted in the car having to be turned off and back on while in active traffic. The vehicle is scheduled to be brought into the suburu dealer of Purchase for inspection for these issues. An issues has also been filed with Suburu of America. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Aug 27, 2026 · Electrical, Engine · IL

24th February 2020 - Bought the car from Subaru dealer. Couple of service records prior to May 24, 2022. - May 24, 2022 (9,037 miles) | RO# 806326: The lower oil pan leaked prematurely and had to be completely replaced under warranty. During the same visit, explained LONG BRAKE PEDAL issue, and was given an estimate. - - June 1, 2022 (9,039 miles) | RO# 806767: Just 2 miles after that repair, the oil pan had to be torn apart again because the internal oil level sensor failed and got stuck. - January 19, 2024 (18,854 miles) | RO# 838995: The vehicle suffered a dangerous engine shutdown in the middle of traffic due to the factory Thermo Control Valve defect (TSB 09-80-21). While resolving this safety defect under warranty, the dealer used scare tactics to upsell me $794.23 out of pocket for unrelated maintenance. - July 3rd, 2025 - You can see from invoice records that indicate, customer requesting a quote on repairing the windshield chips, as I learned on 26th August 2026 (during call with Subaru corporate) that it was under extended warranty, dealership offered me a quote and did not volunteer to repair at no cost nor conveyed information on extended warranty. This damage happened twice due to poor quality of Windshield in my car. - 23rd August, 2026 - This 2020 Subaru Forester has experienced repeated failures involving the Auto Start/Stop system. When stopped in traffic, the system shuts the engine off as designed, but on multiple occasions the engine has failed to restart normally when the driver needed to proceed. This has left the vehicle unable to move in active traffic and created a serious risk of collision. The failures have occurred in highly dangerous situations. - 24th August, 2026 - Similar incident happened the next day. - 25th August 2026 (39,000 miles) | Present Day: The lower oil pan seal has failed yet again. Dealership is suggesting a battery replacement. Shared inspection video shows, rusts on bolts, very unusual for a car driven only 39000.

Filed Aug 19, 2026 · Electrical, Engine · CA

This 2020 Subaru Forester has experienced repeated failures involving the Auto Start/Stop system. When stopped in traffic, the system shuts the engine off as designed, but on multiple occasions the engine has failed to restart normally when the driver needed to proceed. This has left the vehicle unable to move in active traffic and created a serious risk of collision. The failures have occurred in highly dangerous situations, including a busy [XXX], a major [XXX] intersection, and most recently while entering a freeway. In these incidents, surrounding drivers had to brake hard to avoid striking the disabled vehicle. The occupants reasonably feared a serious collision, and the events were potentially life-threatening. The battery was replaced, but the Auto Start/Stop no-restart condition later occurred again, so battery replacement did not resolve the problem. Subaru issued Technical Service Bulletin 16-147-24 on XXX for 2019-2021 Foresters. The bulletin addresses TCM reprogramming related to engine behavior during Auto Start/Stop restart and instructs technicians to reprogram the TCM when the described symptom is reported. However, the bulletin’s warranty section provides reimbursement under the Basic New Car Limited Warranty. For a 2020 vehicle, the original 3-year/36,000-mile basic warranty would ordinarily have expired before this 2024 bulletin was issued. The vehicle is now being evaluated by an authorized Subaru dealer. The condition is intermittent and dangerous because the driver cannot know whether the engine will restart when movement is required. The vehicle is available for inspection. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

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 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 May 3, 2026 · WA

I am filing this complaint regarding a recurring and dangerous safety issue with my 2021 Subaru Forester. The auto stop/start feature intermittently fails to restart the engine after it shuts off when stopped. When this occurs, multiple dashboard warning lights come on, an alarm sounds, and the vehicle requires putting the transmission into "Park" and shutting it down completely before it will start again. This has happened multiple times at intersections, traffic lights, and freeways during rush hour (stopping and starting frequently), leaving me temporarily stranded in live traffic. The local Subaru dealership service department was unable to replicate the issue, however upon inspecting the vehicle's charging system, the battery was found unable to hold charge from the alternator and was replaced on June 9th, 2025. Now after less than 1 year of replacing the battery, the problem persists. I have been made aware of TSB 16-118-24R (TCM reprogramming for auto start/stop restart failure) and TSB 09-80-21 (Thermostatic Control Valve failure) which appear directly related to this issue. This is a serious safety hazard. A vehicle that cannot restart in live traffic puts the driver and other motorists at significant risk of a crash. I am requesting that the federal safety agency investigate this issue and consider a formal recall.

Filed May 3, 2026 · Electrical, Fuel system · MT

Vehicle stopped at light,auto start stop engine off,stepped on gas to go engine didn’t restart,my passenger and I jumped out and grabbed a Noco GB40 jump box I carry and jump started car,we were on a road trip out of town and could not wait for the dealership so finished our trip with the auto start stop turned off and if we had a problem starting used the jump box.