2015 Toyota Prius service brakes problems
84 owner complaints filed with NHTSA name the service brakes on the 2015 Toyota Prius — 52% of all complaints for this model year.
What owners report
“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…”
filed Jun 25, 2026
“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…”
filed Jun 9, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Service Brakes problems in other Prius years
| Year | Reports | Share |
|---|---|---|
| 2024 Prius | 2 | 9% |
| 2022 Prius | 4 | 17% |
| 2019 Prius | 9 | 31% |
| 2018 Prius | 3 | 9% |
| 2017 Prius | 14 | 15% |
| 2016 Prius | 18 | 12% |
| 2014 Prius | 91 | 44% |
| 2013 Prius | 225 | 56% |
| 2012 Prius | 182 | 43% |
| 2011 Prius | 260 | 50% |
| 2010 Prius | 591 | 21% |
| 2009 Prius | 63 | 13% |
Other reported problem areas on the 2015 Toyota Prius
Counts are unique NHTSA complaints naming this component group. Complaints are unverified owner reports; mileage is computed only from complaints that included a usable odometer reading.