2015 Toyota Prius Forward collision avoidance Problems
- Complaints
- 7about this part
- Share
- 4%of 166 total for the year
- Median mileage
- —not reported
- Trend
- Not enough dataFewer than 15 complaints, too few for a reliable trend.
NHTSA recorded 7 complaints about the forward collision avoidance of the 2015 Toyota Prius, 4% of the 166 complaints for this model year.
Fewer than 15 complaints name this part, so treat the figures as a rough indication only.
Example complaints
Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.
“In June 2025, while driving on the highway, the vehicle suddenly displayed multiple brake warning lights and warning messages, including the red brake warning light, ABS light, brake system warning light, and traction/slip indicator. At the same time, the brake pedal became stiff and braking effort increased suddenly, creating a near-crash situation because the vehicle did not slow normally. …”
NHTSA complaint #11725874, filed 2026-03“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, filed 2026-05“While driving, my brakes became mushy and ineffective. Brake warning lights came on, also. It was very scary driving in rush hour traffic with little to no brakes. There was no reliability. Just keeping as much as possible space between cars, using Hazard lights &prayer.”
NHTSA complaint #11710539, filed 2026-01“Failure of brake pump and brake cylinder assembly system, resulting in reduced braking ability and stiff brake pedal. Per Toyota's diagnostic: trouble code C1391 is present, abnormal leak in accumulator, replaced brake ABS actuator assembly, along with brake master cylinder, and bleed the brake hydraulic system. No warning lamps or safety indicators prior to failure. Upon failure (while on freeway going 50+ MPH) the ABS, Brake, and traction control warning lamps illuminated. …”
NHTSA complaint #11668371, filed 2025-06“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. …”
NHTSA complaint #11756229, filed 2026-08Related service bulletins
- 10203533Oct 4, 2021TSB: For proper calibration of the millimeter wave radar sensor, the vehicle and radar target must be on a level surface with a consistent plane. If a level surface with a…
Forward collision avoidance: other model years
| Year | Complaints | Share of year |
|---|---|---|
| 2025 | 3 | 19% |
| 2023 | 1 | 5% |
| 2021 | 1 | 17% |
| 2020 | 1 | 7% |
| 2019 | 4 | 13% |
| 2018 | 1 | 3% |
| 2017 | 1 | 1% |
| 2016 | 2 | 1% |
| 2015 | 7 | 4% |
| 2014 | 6 | 3% |
| 2013 | 12 | 3% |
| 2012 | 3 | 1% |
| 2011 | 5 | 1% |
| 2010 | 18 | 1% |
| 2009 | 5 | 1% |
| 2008 | 3 | 0% |
| 2007 | 1 | 0% |
| 2006 | 1 | 0% |
| 2004 | 1 | 0% |
Other parts of the 2015 Toyota Prius
93 complaintsElectrical system
27 complaintsOther or unknown
15 complaintsTransmission and drivetrain
13 complaintsEngine
8 complaintsExterior lighting
7 complaintsVehicle speed control
7 complaintsAir bags
6 complaintsFuel system
6 complaintsBody and structure
6 complaintsVisibility (wipers, defrost, mirrors)
5 complaintsHybrid propulsion system
3 complaints
← All problems reported for the 2015 Toyota Prius
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 29, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.
To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology