2015 Toyota Prius problems

Filed Nov 7, 2026 · Brakes · MS

Abs, traction light on , and brake light on and the brake is not working good. Need to press it hard to apply brake . It happen with out a reason.i called toyota when i have a recall for that but they refused because it dont have any light sign on it but still it make a loud buzzing sound all time time when car runs and brakes also feels spongy .now recall is expired i have to replace by my self

Filed Oct 3, 2026 · Brakes, Driver assistance · CA

The brake booster pump has malfunctioned, exactly 1 year outside of the secondary coverage supplied in the voluntary customer support program for this exact issue, despite being under 150,000 miles. Now the car is unsafe to drive since the brakes are malfunctioning.

Filed Sep 17, 2026 · Brakes · CA

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.

Filed Aug 31, 2026 · Brakes · HI

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.

Filed Aug 26, 2026 · Brakes · NV

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)

Filed Aug 11, 2026 · Brakes, Driver assistance · CA

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.

Filed Jul 28, 2026 · Seats · NC · crash · 1 injury

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

Filed Jul 15, 2026 · Electrical, Engine · CA · crash

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

Filed Jun 25, 2026 · Brakes · CA

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.

Filed Jun 15, 2026 · Seats · 205,000 miles · IL · crash · 2 injuries

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.