Adaptive Cruise Control Problems of Subaru Forester - part 1

Lately, airbag warning light comes on intermittently often. Sierra Subaru would not fix without charging me for inspection for $240 and then cost of rapair. Also cruise control is malfunctioning where it gets disengaged near the vehicle in front where I have to apply brake hard to avoid serious accident. Also the eyesight not working warning has started showing lately. My Forester 2017 at 44k miles showing airbag light at times along with cruise control disengaing near front car and eyesight not available mentioned above. Detail on airbag fix at sierra Subaru in monrovia, California. On August 12, 2025, I want to get this intermittent error fixed under warranty. On August 12, 2025 alexander in service told me that it will be $240 approximately of charge to inspect. Kindly let me know if the airbag warning light at such low milage not going to be covered for warranty. Please note that I bought the Forester at sierra Subaru monrovia CA and had every single service done there. Lately I have been charged in thousands of dollars at such low mileage to own the 2017 Subaru Forester.

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Several months ago, the automatic front collision activated on the freeway doing about 65mph. There was nothing in front of us, but there was a car behind us that almost rear ended us. I thought this was a one-off thing but reading this site I am not the only one. Also, with in the last 2 weeks the eye site has turned off. This I see is also a known problem.

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My Subaru issues, false warnings to “keep hands on steering wheel” while both hands are holding the steering wheel. The warnings are inconsistent and follow varying sequences. In most cases, the warning begins with a yellow outlined warning, on the instrument panel, to keep hands on the steering wheel with the accompanying beep tones. In most cases, with no change in hand position, the light will go out. In other cases, the outline on the warning will change to red and then go out. In still other cases, the warning will proceed to the cid and be displayed in red with audio. In all of these cases there has been no change in hand position. Usually the light will go out in a few seconds with no change in hand position. In the opposite case, if hands are completely removed from the steering wheel, no warning is given for approximately 12 seconds. In all cases, these false warnings are a distraction to my driving. I consider that a safety issue. In only one case so far has automatic breaking been applied with no reason. My previous car was a 2020 Subaru forrester and I experienced none of these false warnings with that car. It is not clear to me if the false warnings I am experiencing in my car are unique to my particular car or if it is a generic defect in all Subaru. It is my understanding that my current car originated in asheville, north carolina which experienced hurricanes, helene and milton. I wonder if exposure to those hurricanes compromised the electrical system in my car.

While using adaptive cruise control, the vehicle will employ emergency braking even though a vehicle/obstruction is not in front of the vehicle, it is usually diagonal while passing. It, also has been giving a forward collision warning when there is nothing in front of me. Since these events, eyesight has been turning on and off numerous times while vehicle is in operation.

I was driving with adapative cruise on a highway around 65 mph. I can only assume it did a sudden and rapid slow down on its own due fairly defined shadows on the road from tall rocks/cliffs on the side of the road. Luckily I was the only one on the road at the time. It was a clear sunny day. This to me is pretty unsafe if there had been other cars. I have made a service appointment about the issue as well a head unit that is very glitchy.

While driving on a highway, one lane in each direction, my lane was going to end. In front of me were painted yellow highway lines directing me to head right to the new lane on the right side of the steel railings. My adaptive cruise control with lane keeping assistance still had me heading straight instead of to the right. I had to strongly turn my steering wheel to the right to avoid hitting the railing. Also I was following a car into a rotary with my adaptive cruise control on. Thankfully I wasn't going fast and the car started to speed up a little as the car in front of me turned around the rotary. I was able to steer it in the right direction. My point is, some of the new technology is showing commercials with drivers with their hands off the steering wheel, relying on the technology. I was glad I had complete control of the car, but these features aren't perfect.

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Within one month the same thing happened. I turn on the car and the eyesight warning light is on (eyesight feature disabled), flashing "s" drive is on, "break" light is on, and check engine light is on. Due to this cruise control isn't working. My plan was to take it to a mechanic/dealership that Monday. By Monday morning, after about 15 minutes of driving, all warning signs disappeared. This exact thing happened a few weeks later (this morning). I started googling issues and seems like this is an issue for many customers and is just a malfunctioning thermo control valve, no actual problem. What do I do about this? this is much less important - but also seems like a quality issue, at drivers side, the seat cover is starting to crack, looking like this is car is over 10 years old, we've had it for less than 4 years and this shouldn't be happening on a car of this caliber. Photos attached.

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We were traveling on a limited access highway at approximately 65 miles an hour. Both the adaptive cruise control and the driver assist were engaged. A car approximately four car lengths ahead of us exited the highway into the breakdown lane. My car slammed on its brakes and reduced speed to less than 40 miles an hour with no warning. Had there been a vehicle behind us we certainly would have been hit. This is not the first time we have had difficulty with the adaptive cruise control braking unpredictably , but it’s the first time it endangered our lives.

4/2/2024 at 5:30am my eyesight system flashed a message in orange that the eyesight system was off - not temporarily disabled. This is not due to an obstruction of the cameras by weather/glare/dirt etc. All functions controlled by eyesight including lane departure, adaptive cruise control, and forward emergency braking, as well as reverse automatic braking are disabled by this malfunction. I removed the negative lead from my battery in an attempt to reset the system which did not clear the error. No check engine light accompanied this error and all other systems seem to be functioning normally.

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If you have the adaptive cruise control (or regular cruise if you disable adaptive) and accelerate to pass another vehicle, as soon as you take your foot off the gas to coast back down to the cruise setting the car slams on the brakes to bring the vehicle back to the set speed. I have almost been rear ended several times when this happens. This has occurred since I purchased the vehicle. The dealership says this is a design feature and not a defect. It doesn't matter what speed the cruise is set at. If you are exceeding the set speed, the brakes apply when the accelerator is released.

Started engine after parking and check engine light came on, eyesight disabled, and flashing “s”. Stopped driving and took vehicle to dealer. Diagnosed as thermo control unit. Told they didn’t have a loaner and was safe to drive for a few days. Has no heat and engine would not warm up. No safety systems. Retained 3 days later to dealer when loaner was available. Repaired under powertrain warranty.

The thermal control valve stopped working. The car has <50k miles on it. The error also results in many/all of the safety systems being deactivated (no adaptive cruise control, no lane centering, no rear braking, etc. ).

The check engine light came on and all of the eyesight components on the car were disabled as I was traveling down the highway at 70 mph (this included the adaptive cruise control, the lane departure warning, forward collision warning, etc). In addition, the engine thermostat light came on and the heater and defroster stopped working. It was cold and rainy and the window started to fog up and I was unable to clear it without a functioning defroster. This was definitely a safety issue and I had to stop driving. The car was taken to a Subaru dealer today and diagnosed with faulty thermo control valve. The technician told me the car should not be driven in this condition due to the problem being in the engine coolant system. This is a known issue on the 2019 Forester, and other Subaru models as well, and has a TSB originally issued in sept 2021. (#09-80-21) my car has 70k miles and therefore is just out of the warranty period. I will have to pay over $1500 to replace this part and because it is a safety issue I have no choice but to pay for the repair. It is a part that is known to be defective and I am requesting that a recall should be issued before others are also put in potential danger and/or forced to pay large sums of money to get it fixed.

Check engine light is on and the heater control valve needs to be replaced. This part is on back order because so many vehicles need to have this replaced and it turns off all the safety features of the vehicle. This is unsafe, faulty and putting loyal Subaru drivers in a vulnerable position. This part needs to be a manufacturing recall as to replace out of pocket is close to $2,000 and only effects the ac but impairs the safety of the driver.

The thermo control valve malfunctioned causing the check engine light to come on which shut down all the safety features in the vehicle including the front eye sight camera, blind spot warning, the rear automatic braking, lane departure warning, adaptive cruise control, and lane keeping assistance. The check engine computer readout diagnostic trouble code was p26a5 "engine coolant bypass valve "a" position sensor circuit range/performance". The vehicle was taken to a Subaru dealer who found the thermo valve performance was out of spec. This vehicle has not been recalled although the manufacturer replaced the part in 2021 vehicles acknowledging the valve was faulty. Because of the mileage on my vehicle, it was not covered under the warranty although many have been replaced under the manufacturer's warranty due to the failure of this valve under the 60,000 mile warranty. I believe this should be a recall item for others who experience this issue.

Thermo control valve malfuncitoned, causing check engine light to come on. Car only has 72k miles on it, so dealership (mcdaniels Subaru, columbia. Sc) said they couldn't repair under warranty. Even though car has 100k powertrain. To get to this part you have to remove intake manifold, so I don't see how it's not considered part of the powertrain. While check engine light is on, none of the safety features of this car function. From internet research, this part is going to fail, (part has been redesigned due to this), it's just a matter of whether it fails within your warranty period or not. Mine was not.

While I was traveling I stopped at a rest area and when I restarted my car, my panel lit up like a christmas tree. All my safety assist systems were disabled and my check engine light came on. When I got home I had my mechanic run the codes and it came back to the thermo control valve. This happened on 8-29-2023. I researched the problem and Subaru put out a service bulletin in February 2022 but never notified me. My car is out of warranty now and am forced to drive without my safety systems because, 1- they don’t carry the part in stock and 2- the cost to repair is over $1400. 00. Subaru was aware of the problem but kept it quiet. I feel this is a scam and Subaru should recall this part. I was warned that my car could die at any time. I bought it for those very safety systems as I am a senior citizen and rely on them now.

When I turn the car on it flashes check engine eyesite failure which then turns off the ability to use cruise control, crash detection, lane assist, ext. We called dick hannah Subaru and the code came up as p26a5 engine coolant bypass valve a position sensor. They said a thermo valve needs replaced and they’ve seen that happen a lot in 2019/2020 Subarus.

In April 2022 after owning the car for 4 weeks the eyesight went out. I was told it was due to the thermal control module. That was replaced. I’m n June 2023 the ac went out. They said it was the blower motor. That was replaced. In September 2023 the ac went out again. At that point they found the cause was actually a fully melted fuse box and fuses. They replaced the fusebox and the entire ac system. I have had 3 batteries in the vehicle since March 2022. In December 2024 they found that my car needed an update and the update friend the transmission controls module. Then the starter went out at the same time. After that was fixed a week later all the lights in my dash came on and there were no safety features running in the vehicle. I reach out to Subaru and I was told this was all normal wear and tear in the vehicle and it just happens. A melted fuse box and safely features just randomly dying on a 4. 5 year old car goes deeper than that. There has been almost $12000 in repaired performed on this car and the ones remaining are undiagnosed as they have never seen the codes before. This is a mush larger issue and Subaru refuses to do anything.

Was driving in the right-hand lane on the interstate with the cruise control set, went to change lanes as I was approaching a slower moving semi truck going up an incline. Cruise control deactivated with no inputs from myself. Vehicle began to decelerate. Looked at instrument cluster, the check engine light was on along with eye sight off symbol. Additional symbols for forward collision avoidance and rear active braking were also on. No warning signs were present prior to the cruise control turning off. The unexpected loss of power increases the risk of collision while traveling on the highway. Vehicle was taken a Subaru dealer, diagnosed with code p2682, coolant bypass valve performance, with a recommendation to replace the coolant bypass valve.

While accelerating to merge in the freeway the thermo control valve malfunctioned, causing check engine light to come on which turned off all the safety features (lane assist off, precollision off, rab and eyesight off) of my Subaru 2020 Forester sport. I’ve researched the internet and shows it is a common issue. I brought it to a Subaru dealership and was told it is not safe to drive the vehicle. Since I just passed 60k powertrain warranty (around 62k), it is not covered and had to pay over $3,000.

Thermo control valve (tcv) is suspected. I am a member of 2019 Forester group on facebook and reports are quit common for these model year. The check engine light is on and rab system/eyesight is disabled.

* eyesight disabled and thermal control valve-p26a3 diagnostic code. Vehicle is available upon request. * eyesight immediately disabled and maintaining that all safety features are disabled. Safety features that are relied upon, disengaged, and aborted for literally a Subaru known engine issue (TSB #09-80-21) - that is safety at risk to everyone that owns a Subaru with this issue. * 2 independent services confirmed diagnostic- p26a3 *Subaru was requested to review when the vehicle was in for recall inspection. * no warning lamps, messages or any other symptoms of the problem prior to the failure. The warning lights and safety features disengaged all appeared at one time.

My Forester needed new tires at 13,250 miles. I had my tires rotated and that is when Subaru noticed the worn tires. I called Subaru corporate and they informed me that do not replace tires. I bought new tires and then went to have a wheel alignment. The technician told me he could do the alignment but he couldn't adjust the lane assist diagnostic or the vdc and other safety features. Now I am unsure what to do. I have tried to resolve this with Subaru of America without resolution. Hopefully, you will be able to help me. Why are Subaru dealers not doing these adjustments? thanks for your help with this serious situation. Bobette turner.

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When I was driving this car one night, every dash light was suddenly activated and remained on -- and as a result all safety features were deactivated. When I was able to do so, I touched the battery cables together to reboot the system. I had to do this 3 times over the course of 4 days. Realizing the problem was chronic, I took the car to the dealership (a 2 hour drive), where a service tech explained the problem 'was caused by a low battery. ' 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. More important, there is no warning that a 'low battery' -- one which can easily start a car -- could still deactivate safety features while driving.

The thermo control valve has failed and threw a check engine light. This disables the eye sight system and causes no heat or defrosters. There seems to be a huge backorder with no eta in sight for the replacement part. When this part fails there is no defrosters, no crash warning, no emergency braking. . . .

While on freeway at night on 9/28/22 about 8pm several dashboard lights activated including check engine, eyesight assisted safety light, steering and safety controls disabled, all at once! I pulled over and called Subaru for assistance. Called aaa. Aaa suggested I drive vehicle off freeway. I went to brothers and he noted car not overheated and drive short distance home. Car manuals did not explain so many warning lights. Drove car to roseville Subaru next day and determined that engine part had failed to leave for repair. Dealer service agent raj would not provide any details, strange? went online and found Subaru service bulletin #09-80-21 dated 2/28/22 indicating thermo valve defective causing warning lights, and to replace. I felt unsafe as on freeway at risk at night and am elderly. Subaru bulletin shows part faulty as of june7,21 per s. Bulletin. Why not recalled by now? unsafe to drive this car as steering, braking, and driver assistance systems all fail to operate at once and I was not sure if I could control car. Virtually every safety system shut down as simultaneously the speed control, collision monitoring and lane control all stopped working. Furthermore, dealer can't estimate when part is available or provide me a lender car. I am a cancer patient at risk! this car only has 17,000 miles and is not safe or reliable and the dealer won't help. Please help ASAP!.

About a year ago all warning lights came on. Subaru fixed the "rodent" issue for $4000. Today, 8/5/2022 same issue happened, I was driving home and forward braking, cruise control, check engine light, atc temp and dynamic traction control lights came on. This vehicle has some issues.

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Dtc p26a3 thermo control valve ? all my safety features are disabled until the part becomes available- it is apparently on back order and/ or not part of an active recall or both ? having difficulty getting information from my dealer/service dept.

I took our 2018 Subaru Forester through a car wash. The usual washing procedure went just fine with me in the car idling in neutral as it went through. When it came to the end of the wash cycle, I coasted out and then shifted into drive. Instantly the car surged forward at an alarming speed and I could not stop it. The car crossed a busy street. I fortunately did not collide with cars. The car continued into a field next to a Ford dealer’s lot at a high speed and I was unable to stop it. I managed to swerve right to avoid crashing into the cars parked on the Ford lot. This sent the car back toward the road. Fortunately I hit a lone fire hydrant along the road, shearing the hydrant completely off. The hydrant was dragged along under the front left tire until it hit the curb stopping the car. The air bag did not deploy and I was not injured. This all occurred in a matter of seconds.

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During the January snow storm in the washington, DC area the adas system began to malfunction. The system that controls adaptive cruise control, automatic emergency braking, forward collision warning and lane departure warning all shut off. The vehicle was parked at an upward facing angle in order to allow all moisture to drain out/off the back of the vehicle. Once dry, the issue resolved itself. The same issue happened in the past and was tied to an issue with a brake light switch. It appears that the same issue is occurring again on the vehicle and moisture is still effecting the brake light switch.

While driving n on I 24 near nashville TN my eyesight assistant turned off illuminated warning light, as it cancelled my adaptive cruise control at freeway speeds in heavy traffic, while engageing my my brakes and illuminated my forward collision warning coming very close to causing serious accident to whereiended up on shoulder due to severe vibration from my defective passenger lower control arm deffectivecv axle. All of which were looked at and reported to crown Subaru service department. They had my vehicle for 2 days, repaired air bag and rearcoil spring recall told me my passenger lower control arm was bent and cv axle was defective the stayed my extended warranty didn't cover it when the warranty personnel said it would be covered. Never even checked my eyesight assist or other safety items associated with it even though I explained it shutoff and turns on and off sporadically. Is it going to take a death or deaths to get these people to do there job and repair and stand by the vehicles we purchase which employees them but a life isn't worth and hour inspection by crown Subaru or Subaru corp start caring. It was in there shop 2 days prior to incident I could have at least been warned about operation of my vehicle.

Our windshield spontaneously cracked and the crack has grown very quickly. I looked online only to see that this has happened to several others.

Rock damage to windshield. Subaru advises to replace with oem glass to guarantee safety systems operate correctly making this a safety issue. The problem is that Subaru windshields are back ordered. There are two problems here. First, Subaru windshields are very susceptible to damage, perhaps more than others. Second, Subaru fails to maintain critical safety system parts.

July 31, 2021i noted an approximately 6-inch unprovoked crack originating at the outer edge in the windshield on the passenger side. The beginning of September I went to Subaru city, milwaukee, WI and pictures were taken by the assistant manager, eric and sent to Subaru. I returned November 23rd after no follow up to find out "more pictures were needed" per the assistant manager. Again, no follow up so I returned January 19th, and had yet more pictures taken by another employee, [xxx] because they couldn't locate them. I received a call back the next day to confirm submission. After no response to about 10 phone calls to the assistant service manager again, I returned March 7th and was told by another employee, [xxx], there was a new database and couldn't find the pictures. Then was called back and told not under warranty despite requesting repair due to industry defect in the windshields with eyesight. The crack has extended to about 12" from the driver's side edge. I'm concerned about the integrity of the windshield should there be an impact and the eyesight isn't reliable with this crack. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

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