2015 Toyota Prius

165 complaints on file, page 1 of 9.

1. Filed Sep 17, 2026Failure Sep 7, 2026los angeles, CAService brakes

   I am reporting an active, severe safety hazard regarding the braking system on my 2015 Toyota Prius ( Mileage: 79,000). The vehicle has been officially diagnosed by Toyota Culver City with Diagnostic Trouble Code DTC C1391, confirming an internal failure and lack of pressure within the brake booster/actuator assembly. This component defect causes an immediate compromise to the vehicle's braking efficiency and hydraulic pressure, causing a sudden loss of braking power and significantly increasing stopping distances.Toyota was fully aware of this dangerous defect and initiated Customer Support Program ZJB to address it. However, Toyota Brand Engagement Center (Case #260909002032) has explicitly admitted via recorded voicemail that they mailed the safety/defect notification only to a previous owner and failed to notify me. Because they did not cross-reference current registration data, I was never notified of the defect and was deprived of a preemptive remedy before their arbitrary 10-year calendar clock expired. At only 79,000 miles, this critical safety component has failed prematurely, creating an active hazard on public roads. Toyota is refusing to cover the $3,890 repair despite their documented failure to notify the current owner.

   NHTSA complaint 11765138
2. Filed Aug 31, 2026Failure Aug 23, 2026Honolulu, HIService brakes

   Problem: Brake Actuator is pulsing the Booster Pump to keep running intermittently, 5-10 seconds. Console lights lit up for ABS problem. Does not clear. Toyota Dealership Report: DCT C1391 Abnormal Leak: Monitored TEH Accumulator Pressure and its not holding pressure. Pump keeps running. Rec[ommend] Brake Actuator and Booster Pump Assembly [replacement].` ServCo Toyota dealership in Hawaii Report: Submitted Prior Authorization request with Toyota Hawaii Warranty. Request Denied for Goodwill Coverage on ABS Actuator and Booster Pump.

   NHTSA complaint 11760825
3. Filed Aug 26, 2026Failure Aug 15, 2026Alamo, NVService brakes

   On XXX, I was driving my 2015 Toyota Prius with my family in the vehicle and approaching stopped traffic on dry pavement. An emergency vehicle was approaching from behind, so I began braking earlier than usual. When I applied the brakes, the vehicle did not stop normally. The front slowed/stopped while the rear of the Prius suddenly slid sideways toward the adjacent lane, bringing the rear passenger side dangerously close to another vehicle. Had I begun braking at my normal stopping distance, I believe a collision would have occurred. No crash or injuries occurred, but the incident was extremely dangerous. I drove the vehicle very slowly to Purrfect Auto Services, [XXX], where the brake/ABS system was diagnosed. I observed diagnostic code C1391. The shop has had the vehicle since XXX and has experienced repeated problems with used replacement brake-system components that were defective or would not function properly. The vehicle has remained unsafe to return to service while the shop works to obtain a properly functioning replacement part. I am reporting this because the sudden and unpredictable braking behavior created a serious risk to my family and other motorists. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

   NHTSA complaint 11759804
4. Filed Aug 11, 2026Failure Aug 6, 2026South Pasadena, CAAutomatic emergency braking, Service brakes

   Code DTC C1391 - Abnormal leak of accumulator pressure. Internal failure of the brake booster pump assembly, preventing the system from maintaining proper hydraulic pressure. This means the brakes don't work, putting the driver's and passengers' lives at risk. This DTC C1391 code and problem were reproduced and confirmed by an independent service center who specializes in 3rd generation priuses. There were warning lights that lit up when the brakes failed - the ABS, traction control, and brake light all lit up but only after the brakes had stopped working. This is a known manufacturer defect but toyota won't pay to fix it because they put a 10 year limit on first driven date or 150,000 miles. This prius only has 100k miles but toyota still won't stand behind their product even though they have admitted it was a manufacturing defect and they sold a defective product.

   NHTSA complaint 11756229
5. Filed Jul 28, 2026Failure Jul 27, 2026Fuquay-Varina, NCSeatsCrash1 injured

   I was rear-ended by a truck in my prius and my seat laid back on impact. I'm unaware if that was an intended thing or not but it potentially could have injured my neck. My car is currently in a storage lot awaiting the adjustor's inspection so it is available for inspection if needed. No warning lights were available and it hasn't been recreated by the dealer

   NHTSA complaint 11753382
6. Filed Jul 15, 2026Failure Jun 28, 2026Huntington Beach, CAElectrical system, EngineCrash

   Pulling out of a parking stall, when put vehicle in drive, the engine revved up and accelerated - vehicle crashed, the brakes did not work- there was skid marks. Floor mats are factory OEM were installed properly. I did not hit the accelerator and I am in good health and mind. I have driving for over 30 years, never had and accident nor a ticket! - A county officer was at the seen and left me with vehicle that had to be towed away. The Vehicle is a total loss. I have insurance but felt that this incident need to be reported, There is no safety recalls and the vehicle was always property maintained

   NHTSA complaint 11750516
7. Filed Jun 25, 2026Failure Jun 23, 2026Redlands, CAService brakes

   The vehicle experienced a failure in the braking system involving the brake booster/brake actuator assembly. The vehicle displayed diagnostic trouble code C1391, which is associated with a malfunction of the brake booster pump/accumulator system on this model. The failed component is available for inspection upon request. The failure created a safety concern because the braking system warning lights illuminated and the vehicle’s brake assist system may not function properly. A malfunction of the brake actuator/booster system could increase stopping distance, reduce braking performance, and create a potential risk of a crash, especially during emergency braking situations. The problem has been confirmed through diagnosis showing the C1391 trouble code. The issue has been identified as a brake system malfunction requiring repair of the brake booster/actuator assembly. The vehicle has been inspected/diagnosed by a service professional. The vehicle has not been inspected by police or insurance representatives. Toyota/dealer inspection information is available if requested. I contacted Toyota regarding the issue, but they declined assistance because the extended warranty coverage expired approximately 7 months prior to the failure. Before the failure, the vehicle operated normally. The first symptoms occurred when multiple warning lights appeared while driving, including the ABS warning light, brake warning light, parking brake warning light (even though the parking brake was not engaged), and the traction control/slippery road warning light. These warning lights appeared suddenly, indicating a problem with the braking system.

   NHTSA complaint 11746503
8. Filed Jun 15, 2026Failure Jun 10, 2026205,000 milesCarpentersville, ILSeatsCrash2 injured

   The contact owns a 2015 Toyota Prius. The contact stated that while driving and coming to a complete stop, the vehicle was rear-ended by another vehicle driving approximately 35-45 MPH. The contact stated that upon impact, the front driver's seat unexpectedly reclined and struck the rear passenger’s seat. The contact was concerned about the movement of the seat and stated that an occupant seated directly behind the driver's seat could have been injured. The rear bumper, trunk, and rear body structure sustained damage from the crash. The contact stated that the force of the impact caused the rear driver’s side body panels to flare outward and become deformed. No additional property damage had occurred from the crash. The vehicle remained in the roadway following the crash. There was no warning light illuminated. The contact sustained neck injuries, whiplash, and emotional trauma from the crash. Medical attention was sought. The Uber passenger inside the vehicle was also transported from the scene to seek medical attention and treatment; however, the extent of the injury was unknown. The contact considered the vehicle a total loss by the contact, but the vehicle was not declared a total loss. The vehicle was towed to a tow yard. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 205,000.

   NHTSA complaint 11744174
9. Filed Jun 10, 2026Failure Jun 6, 2026121,000 milesScottsdale, AZService brakes, Hydraulic

   The contact owns a 2015 Toyota Prius. The contact stated that while driving at 45 MPH, the brake warning lights illuminated. The brakes were inoperable and entered manual mode. The contact stated that the brake warning lights were red and yellow. The vehicle was taken to Brake Masters, where it was diagnosed with brake actuator failure. The local dealer was contacted but did not provide assistance. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 121,000.

   NHTSA complaint 11743224
10. Filed Jun 9, 2026Failure Mar 28, 2026Cumming, GAElectrical system, Service brakes

    The incident involved having to press extremely hard on the brake pedal to stop the car, while it was uphill in the middle of the road. The car started going backward and was throwing ABS, Master Warning Light, Brake System Warning Light and Warning Buzzer, Brake System Warning Light, and SLIP Indicator signals. This was a highly distraughtful situation on the road. Diagnostics showed C1391 Diagnostic Trouble Code on the 2015 Toyota Prius: brake booster and brake booster pump problem. When pressing the brake pedal there is a high pitched metal scraping noise. Toyota coverage program is only applicable for 10 years from the date of first use or 150,000 miles, whichever occurs first. Many cars run well for over 10 years with good care, so the 10 year cap barely covers anything. This is highly unfair and borderline scamming for an issue so severe, which can cause big accidents on the road. In all honesty, this is a life or death situation when it comes to not being able to properly brake while driving. This should be a full recall!!

    NHTSA complaint 11742921
11. Filed Jun 3, 2026Failure Dec 17, 2025Atlanta, GAElectrical system, Service brakes

    The brake pump and actuator on my 2015 prius has been faulty and the repair was apparently covered under the customer support program but it expired in December. I had no knowledge of it and when I took my car in to a toyota dealership, no one told me about about the profram but told me that they needed to be replaced. I did not get the repair because of the hefty cost and I missed the deadline. My safety and the safety of other drivers were put at risk for not allowing me to be notified by it and my car being at risk for my brakes failing at any time. Their were absolutely no warning lights on my vehicle as well.

    NHTSA complaint 11741829
12. Filed May 30, 2026Failure Jan 1, 2025Portola Valley, CABody

    The factory clear coat has delaminated

    NHTSA complaint 11741039
13. Filed May 28, 2026Failure Dec 31, 1969Manchester, NHUnknown or other

    Unknown

    NHTSA complaint 11740742
14. Filed May 26, 2026Failure May 6, 2026Ontario, CAAutomatic emergency braking, Service brakes

    Code C1391 200k miles All the warning signs for brake booster issue came up. The cost is too high and I just missed the Customer Support Program timelines because the code came up late. This needs to be a RECALL, based on how many people experience this issue consistently.

    NHTSA complaint 11740166
15. Filed May 26, 2026Failure May 23, 2026santa cruz, CAService brakes

    I was driving my 2015 prius for years and occasionally the brake, abs and traction light would come on this is a sign of a failing Brake actuator and booster. Toyota and the Ntsb ordered the following warranty enhancement https://static.nhtsa.gov/odi/tsbs/2020/MC-10181800-9999.pdf My Brake Booster had been exhibiting signs of failing for years and I tried to get a toyota dealership to replace and repair the parts under the warranty extension but I was told I had to wait until I had perminent dash lights and trouble codes. So I had to wait till the booster completely failed. By that time my car had exited the extended warranty perimeters and I am told it is no longer eligible.... even though the components are faulty from the factory and exhibited signs of failure many years prior. I was told to wait until the compenent failed by multiple dealers. My car was in motion and the brake boosters failed, fortunatly it did not cause an accident but this is a serious safety issue. Toyota should have done a compleat recall of the brake actuator and booster pump, rather than have drivers use known faulty components until failure. Toyota corporate has refused to help in the repair of the vehicle despite it showing failure for years.

    NHTSA complaint 11740085
16. Filed May 10, 2026Failure May 4, 2026Valencia, CAService brakes

    Toyota Prius has a known problem with the brake actuator and booster. A notice was sent out in 2019 under the Customer Support Program Expansion with repairs up to 10 years or 150k miles. This is a safety issue and should be covered under a recall with NO TIME OR MILEAGE LIMITS since these problems are not showing up until after 10 years if the car has low mileage, as in our case. We just passed the 10 year mark, but only has 114k miles. No mention of repairs needed were made during regular maintenance visits with Toyota. Additionally, preventative repairs were not offered if the vehicle did not seem to be experiencing problems at that time. The brakes are spongy and unresponsive. The ABS light , traction warning lights, and parking brake lights are staying on.

    NHTSA complaint 11736895
17. Filed May 7, 2026Failure May 5, 2026Torrance, CAService brakes

    ABS braking system suddenly not working. ABS, BRAKE, and traction control lights all turned on.

    NHTSA complaint 11736350
18. Filed May 6, 2026Failure Apr 16, 2026Downey, CAService brakes

    On 4/16/26, while driving my 2015 Toyota Prius (approximately 87,000 miles) on the freeway, I applied the brakes while transitioning from the [XXX] onto the [XXX] . As I veered right on the curved onramp, the brakes failed to engage properly, causing the vehicle to spin out of control and collide with the side railing. There were fortunately no nearby vehicles on the 2-lane onramp at the time. Under slightly different circumstances, this incident could easily have resulted in serious injury or death to myself and/or others. No airbags deployed. Although I was physically unharmed, I was extremely shaken by the incident. Immediately after the collision, the brake warning light, ABS warning light, and another warning indicator illuminated on the dashboard. Prior to the incident, I had not experienced braking problems severe enough to suggest imminent failure. On 4/17/26, I brought the vehicle to Toyota of Cerritos for diagnostic evaluation. I was informed that the brake booster was the issue and that the vehicle was unsafe to drive. The vehicle was towed to a collision repair center affiliated with my insurance company. After repairing the external collision damage, the collision center informed me that the brake booster malfunction that caused the incident could not be repaired there and would require dealership service. External repair alone: $3706, in addition to increased automobile insurance premiums expected over the next 3 years. I also contacted Toyota Motor Corporation regarding Customer Support Program coverage related to brake booster issues and was informed that the program expired in 2025 and no assistance would be provided. I am submitting this report because this brake booster malfunction created a serious and unexpected safety hazard resulting in loss of vehicle control on a freeway interchange. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

    NHTSA complaint 11736160
19. Filed Mar 20, 2026Failure Mar 20, 2026Raleigh, NCService brakes

    My brake actuator and brake booster are failing. All of my dashboard lights have come on (brake, ABS, Traction Control, brake system warning light). Unfortunately, I am over 10 years and Toyota is saying that I need to pay out of pocket for the repairs. This is a known problem and should be covered. I was unaware of the known issue and my car didn't start having problems until after the 10 year mark. I am under 150,000 miles.

    NHTSA complaint 11725978
20. Filed Mar 20, 2026Failure Mar 7, 2026Redondo Beach, CAService brakes

    Brake Booster and ABS, Brake Master Cylinder went out in car without any lights or warning while driving the vehicle at a moderate speed on Freeway. I was able to avoid an accident and take the car to a repair shop in which at 119K miles and just at 10.5 yrs old the entire brake system had to be replaced/repaired.

    NHTSA complaint 11725935