Toyota Prius whining noise problems

Filed Oct 21, 2026 · Brakes, Driver assistance · FL · crash

The Toyota Prius, models through 2010 - 2015 have a known issue with the Brake Booster (actuator) and ABS Pump where the parts will degrade and break at or around 100,000mi. Toyota issued a bulletin and had a replacement program that covered the part that has since elapsed but has not corrected the issue with existing stock and inventory so the problem remains. When I purchased my car I was the 2nd owner, the car was purchased with roughly 160,000mi. The previous owner had informed me that he already replaced the actuator and ABS pump so I wouldn't have to worry about that repair. All told he said he spent $4000+ on the repair. When the car was driving I heard a high pitched whine. I took it to garages after my OBD tools could not identify the issue, no one had a fix and speculated that it was a power inverter and it was normal. Some weeks later, I was involved in an accident where the car did not stop in time, the brake went spongy and locked up, ABS failed to activate with no warnings or indicators. This is what first led me to suspect something wrong with the ABS. later the persistent whine was loud enough that I could identify that it was hydraulic in nature, pointing to the brakes. Within weeks the whine had stopped and my brake, ABS, and TCS lights came on, on the cluster. My OBD indicated that the ABS pump and Brake actuator were giving codes to the ECM. I replace it, and at about 240,000mi it went out again. Due to the extremely expensive nature of the part I purchased a used part which is now also bad. Toyota informed me that they have no intention of passing a recall notice or fixing the defective part. I would imagine that if the NHSTA looked into crashes involving this model and year group they would see an unusually high trend of these getting into an accident around 100,000mi increments. I believe that a recall should be issued due to the serious safety implications of potential defective cars on the road that may not be able to brake in time.

Filed May 17, 2021 · Brakes · HI

Impending failure of the brake booster / brake booster pump assembly. ABS and brake warning lights remain on and a constant electrical whining sound can be heard from the brake booster assembly. Toyota is aware of the problem and offered a customer support program that expired in 2019 ( https://attachments.priuschat.com/attachment-files/2019/12/178663_162714_ZJB_Phase_2_.pdf )

Filed Apr 26, 2021 · Brakes · 95,000 miles · FL · crash

I cannot stop my car in time, it feels like I am fred flinstone trying to use my feet to stop. I have rear-ended another car. I have no car to drive as it is not safe. Kendall west toyota gave me car back and said part of recalls completed but unable to complete other recalls. They said ABS fixed but it is not as still makes the same whining sound and I cannot brake. I have to use all my strength to push as hard as humanly possible. I have to pay for rental car. Kendall toyota could not provide a time frame of when my car would be fixed.

Filed Jun 24, 2020 · Airbags, Brakes · 150,000 miles · AL

When I go to hit the brakes the car won't stop and the rear end makes noise and raises up. The ABS and brake lights are one as well as maintenance required and SRS airbag light. The master alarm buzzer is on and won't go off. Brakes engaged without hitting the brake causes rim to overheat and brake fluid gets extremely hot. Also sometimes when tap on the brakes they will lock up and you will go sliding sideways or tap the brakes and they straight to the floor. Also the brake actuator starts whining noise and won't go off even if the car is turned off. Don't have documentation from a mechanic but can send video of driving it.

Filed Aug 28, 2019 · Brakes, Driver assistance · 130,000 miles · MN

My 2011 prius very recently has started making audibly noise while pressing the brake pedal, whether in motion or stopped. This noise contains continuous whirring, whining and loud clicking noise. These noises where not seen before completely. I spoke to dealer mentioning a tsb pertaining to this particular issue in specific and was told nothing can be done until it fails completely, which is bad, as I have a family of 3 and god forbid if this were to happen while driving on freeway, a serious safety hazard and toyota dealer (rudy luther) response is irresponsible. I am actually worried more now on waiting for the brakes to fail. This loud continuous clicking noises occurs the moment car is turned on and the noises lingers on for short while after the car is turned off, at moments I have to press on the brakes really harder than usual to get the car slowed and is a tremendous panicky situation. I am registering and requesting for this to be looked immediately before any catastrophe.

Filed Jan 16, 2019 · Brakes · 113,000 miles · CA

Will randomly refuse to stop on demand. Very loud whining noise coming from brake actuator when brakes are pressed. Cannot drive this car anymore. Over $1500 to replace!!

Filed Oct 17, 2018 · Brakes · 175,000 miles · CA

Park, ABS, vcs, (!) warning lights on in dashboard. Other symptoms - barking brakes and continuous pump whine, a cylcing electrical noise while parked. Seems to be an issue with the actuator.

Filed Apr 15, 2017 · Transmission · CA

My new tacoma has a whine/howl coming from the rear differential. Per my dealer, they have started a tas case with toyota corp and were advised that the condition described is known, and under investigation. Tas says there are no recommended repairs at this time. The problem is occurring between 30-65 MPH when decelerating and feathering the throttle, but is now becoming more pronounce with time and more mileage. I'm concerned that the issue could potentially become a safety issue. This issue is occurring with 2016-17 tacoma's. Many differentials have been replaced by dealers; even the replacement differentials are experiencing the same issue.

Filed Oct 1, 2012 · Suspension · 38,000 miles · NH

Tl* the contact owns a 2010 toyota prius. The contact stated that the rear passenger side wheel bearing failed. The contact mentioned that the failure was causing the rear passenger side to make a howling sound. The vehicle was not taken to the dealer. The failure mileage was 38,000 and the current mileage was 39,000.

Filed Sep 13, 2010 · Acceleration · 19,000 miles · MO · crash

We were backing down our driveway in our 2009 toyota prius. As we approached the street our car suddenly made a loud whining noise and started accelerating backwards. Before we could do anything, we backed into the car parked across from our driveway. After we collected ourselves, we decided to move the car out of the street into our driveway. The sudden acceleration happened again, but this time my husband reached over and hit the park button and we stopped before we hit anything. I have driven our other two cars down our long driveway since, and we only use the accelerator to start the car moving. After that, we are braking all the way down the drive. The acceleration occurred near the street where we pause to check on the traffic. Now that I have checked myself with our other cars, I am sure I did not have my foot on the accelerator pedal at the bottom of the drive, as I brake all the way down. Our prius is over at the dealer, and we have filed a complaint with toyota. We are afraid of the car. We did have the car fixed at the recall.