Subaru Ascent adaptive cruise problems

Filed Oct 31, 2026 · Driver assistance · ID · crash · 1 injury

2021 Subaru Ascent was involved in a serious collision with highway maintenance equipment near [XXX]. The vehicle's EyeSight Driver Assist Technology, specifically Adaptive Cruise Control and Pre-Collision Braking, is suspected of failing to respond appropriately to slower-moving equipment directly ahead. At the time of the collision, Adaptive Cruise Control was actively engaged and controlling vehicle speed. Lane Centering, Lane Departure Warning, and Lane Keep Assist were also enabled. The vehicle was traveling within its designated lane when it approached a highway maintenance truck equipped with a rear-mounted crash attenuator. The maintenance truck appeared to be moving slowly in the same lane. Despite Adaptive Cruise Control controlling vehicle speed, the Subaru did not adequately slow to avoid the collision. The driver reported no effective forward collision warning or automatic emergency braking intervention. Whether the system detected the equipment or attempted braking is UNKNOWN. The impact caused extensive front-end damage and airbag deployment. The driver was pregnant, and two children, ages [XXX] and [XXX], were passengers. All occupants and the unborn child were placed at significant risk of serious injury. Whether any EyeSight warnings, fault messages, or diagnostic trouble codes were present before impact is UNKNOWN. The suspected malfunction has not been reproduced or confirmed by a dealership or independent service center. A manufacturer engineering inspection has not been confirmed. Photographs document the accident scene and vehicle damage. The extent of police or insurance technical inspections and the vehicle's current availability for inspection are UNKNOWN. An investigation is requested into Adaptive Cruise Control, forward object detection, and Pre-Collision Braking, including preservation and review of available electronic collision data to establish why the systems did not prevent or effectively mitigate the collision. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (F

Filed Oct 28, 2026 · Driver assistance · IA

This happened three individual times, all traveling at highway speed under similar conditions. The panel began flashing in red claiming that no driver was responsive and threw on the ABS breaks. I was able to regain control after disengaging the adaptive cruise control system. At the time the the daytime road conditions were clear, I was clearly visible to the driver monitoring system infrared camera, and both hands were at 10 and 2 on the steering wheel. The dealer has been made aware of this but have been reluctant to address it, claiming that this happens to everyone. This could easily have resulted in a rear-end collision had there been more traffic on the highway.

Filed Jun 25, 2026 · Driver assistance · TN

Traveling in my 2025 Subaru Ascent with cruise control set at 50mph. Bright sunny day, no shadows on the road and no vehicles in front of me. My vehicle slammed on the brakes out of nowhere. Held deceleration about 5-7 seconds and then resumed cruising speed. The road I was on is generally busy. I got very lucky there was no one behind me or I would have been rear ended.

Filed May 16, 2026 · Acceleration, Steering · SC

While cruising on a 2-lane road or a freeway, the vehicle will cross over the adjacent line, either left or right. This generally happens between 50 to 75 mph. The event happens either when cruise control is on or off. Wind is not necessarily the problem. The solution requires one to take the necessary immediate steering correction. At times, the departure from the lanes may repeat. This may be a temporary correction. This may create a head-on collision if not immediately correctly manually. VERY DISTURBING!

Filed Apr 16, 2026 · Acceleration, Driver assistance · NC

In 2024, 2025, and 2026, I have had 2 incidents in each year where the cruise control is set to 60 to 65 mph and the cruise control then accelerates the car past 100 mph. When this occurs, tapping the break does NOT disengage the cruise control. All 6 times I have had to slam the breaks to a full dead stop while the car tries to accelerate anyway. April 4, 2026 and April 14, 2026 are the most recent occurrences and all occurrences so far for this issue have been during a downhill road incline. The dealer has dismissed the problem every time and has been unable to fix or reproduce the problem on demand. The random frequency of this problem can easily lead to a significant accident for the driver or others in the vicinity. And the lack of resolution from the Subaru dealer has lead me to report the issue here in hopes that if this is occurring for other vehicles that the company takes an actual resolution to solve the issue in their cruise control function.

Filed Dec 12, 2025 · AK

Vehicle: 2020 Subaru Ascent Issue: Cold weather software glitch If you are operating an Ascent or possibly other Subarus with the CVT in temperatures below -20F be certain to have either a small wrench or the appropriate size socket to loosen the ground clamp on the battery ground cable with you so you can employ what I call the magic Windows fix wherin one completely de-powers the system and reboots it. With all the ridiculous interconnections, if the CVT temperature sensor thinks the tranny is too cold the cars operating system looses it mind and goes completely bonkers. Subaru obviously did no cold weather testing. We have had 2 failures in cold weather. It only happens at temperatures well below the-20F range. The first case happened last year while driving after being stopped for a couple of hours. Everything seemed normal and then suddenly several warning lights came on and all of the safety systems and the eyesight system shut down. The car ran and drove, but none of the associated systems would work. No traction control. No cruise control. Several other systems. The only solution was to disconnect the battery and get this rolling computer to reboot. This was a temporary fix as the condition repeated itself although the car was driveable but with none of the safety systems operational. This year we were out in cold weather, -25 to -32. We went to a place to have lunch and when I went to restart the car the app failed to do so. So I put on all my gear and went out to start it manually. It would not start and all the warning lights were on and the radiator fan was running full tilt at -25F with the car off. I tried twice to get it going by pulling the battery cable to get it to reboot. Evidently when this happens you must leave the battery disconnected long enough (about 5 minutes) for all the capacitors in the electronics to drain. Once restarted, the car drove normally but we did not shut it down for any reason for the rest of the day.

Filed Sep 16, 2025 · Driver assistance · IN

When crossing a bridge at 40 mph with wide open lanes and shoulders the vehicle on cruise control suddenly braked aggressively and came to a full stop in the middle of a state highway bridge. Conditions were daylight, headed towards sun, no shadows on bridge. The road surface was smooth asphalt. There were shoulders as wide as the active lanes. There was no warning and very little time for a driver reaction. This type of vehicle behavior will most certainly cause rear end collisions.

Filed Sep 8, 2025 · Engine, Steering · VA

My vehicle has lost eyesight too many times while am driving on high way so steering wheel locked, adater,cruise control sign appears together .just a second my family had almost died due to vacation time in august,2025.I cant believe that is brand new subaru ascent touring 2024 I purchased from march ,2024. We found subaru dealership at las vegas ,na but technician of there responded to me that : they dont know exhaust button number and they are not sure my car still safe or not safety when I am driving on the highway, (my family has 7 peoples from [xxx] old to [xxx] old ,we had to sleep at gas station over 2 nights with out electronic,..) they answered to me that : they can not fix it. Their answer made me scared because we need to a car go back home .we can not drive it anymore ,I decided trade it to chevrolet to purchase other brand new car on aughust 9,2025 to back home. I wanted to subaru manufacture must be responsible to my new expenses vehicle like insurance higher, loan interest higher. The car only 14,823 miles, I spoke to salesmanager at my dealership and requested refund but he did not have resolve to me and keeping quiet until now.if my whole family die from subaru corporation from their technology error,who will return our life? Information redacted pursuant to the freedom of information act (foia), 5 u.s.c. 552(b)(6)

Filed Feb 19, 2025 · Transmission · OR

Ever since our car went in for re-programing CVT drive chain it progressively has been having a problem of something slipping in drive and in cruise control. feels like a loss of power and a feeling chatter from transmission. Now when you put it in drive it makes a jerking noise. the thing is that we never had this problem until it went in for this recall. it's been back twice and they claim they can't find any problem but continues to get worse. it happens every time we drive it . just returned a 700 mile trip and it's very annoying. Also we do have an extended warranty.

Filed Jan 17, 2025 · Brakes, Driver assistance · WV

Started the vehicle to drive 30 miles for an appointment. While driving, all of the intrument cluster lights illuminated. The eye sight turned off, cruise control no longer worked, parking brake light was illuminated, ABS light was illuminated. Tpms light was illuminated. This has occured 2 times before. The fix for the previous issues was to clean the battery terminals.