2014 Toyota Prius driver assistance 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 Jul 2, 2026 · Brakes, Driver assistance · CA

The traction control, abs, and emergency brake light came on. We checked and the code produced was C1391. There’s a humming noise every 10 or so seconds when idle. The humming noise is also present when braking. We did some research and this appears to be an issue with Toyota Prius. We called the dealership and were informed that this was not a known issue. Thank you.

Filed Jun 1, 2026 · Brakes, Driver assistance · VA

ABS, traction control, brake system, and brake lights turned on while driving. Took the car to the mechanic and pulled the code C1391. It seems from other complaints to the federal safety agency that it is a common issue and quite dangerous, meaning the brake system is failing.

Filed Dec 26, 2025 · Brakes, Driver assistance · NJ

The brake system malfunctioned suddenly. While driving and while stopped, the brake pedal became very hard and braking behavior became unpredictable. The vehicle sometimes brakes aggressively and other times requires excessive pedal force to stop. The ABS and BRAKE warning lights illuminated. The vehicle no longer provides normal braking assistance. This issue is related to a failure of the brake actuator / brake booster, which is a known issue affecting Toyota Prius models from 2010 to 2015. This defect creates a serious safety risk, as braking performance is inconsistent and may increase stopping distance or cause loss of control during emergency braking situations. The vehicle has not been repaired yet because the cost is very high and the manufacturer has declined assistance despite this being a known safety-related defect.

Filed Aug 12, 2025 · Brakes, Driver assistance · 150,000 miles · FL

The contact owns a 2014 Toyota Prius. The contact stated that the ABS and the traction control warning lights were illuminated. The vehicle was taken to the dealer to be diagnosed, and the contact was informed that the brake master cylinder needed to be replaced. The vehicle was not repaired. The vehicle was taken to a certified mechanic and was diagnosed, and it was determined that the brake booster had failed and needed to be replaced. The vehicle was repaired; however, one day later, both warning lights returned. The vehicle was returned to the mechanic and air was blown into the hydraulic valves and the other valves were cleaned; however, the failure persisted. The manufacturer was not informed of the failure. The failure mileage was approximately 150,000.

Filed Mar 22, 2025 · Brakes, Driver assistance · CA

Failed Brake booster and pump assembly, confirmed by Toyota service. Warning lights turned on all at once: AEB, skid control and brake light. Estimated cost to repair is $3,000.

Filed Mar 10, 2024 · Brakes, Driver assistance · FL

Code C1391 - Abnormal Leak in Accumulator. Accumulator for the brake pump is not holding pressure so the pump has to keep turning on to refill. Brake pump and ABS unit have to be replaced. In emergency situations, a malfunctioning ABS module leads to increased stopping distances and loss of steering control during hard braking. Lastly, tires can be worn more easily, which could lead to tire blowouts. This puts myself and others at risk for deadly consequences due to an increased chance for collision if I am unable to control or stop my car. This problem has been confirmed by Toyota and multiple years of Toyota vehicles have had their brake actuator assembly warranty enhanced. The warranty enhancement program has secondary coverage, which is applicable for 10 years from the first date of use, or 150,000 miles, whichever occurs first. Currently I meet the 10 year requirement but have 162,000 miles on my prius, which is completely frustrating. Many have posted with the same problem of being just outside the warranty. The vehicle has been inspected at a Toyota dealership. A symptom was noticeable starting from over 1 ½ years ago when I was under 150,000 miles. The car produced clicking sounds when the brake pedal was held down at traffic lights. Once released, the clicking sound would stop. I spoke with a Toyota mechanic and he told me it was an issue with the brake pump and ABS unit, but Toyota would not repair it until it completely failed. He also mentioned that there was coverage available for the ABS unit once it failed as it was a common issue for the Toyota Prius. If Toyota warranty allowed for the brake pump and ABS unit to be replaced when the symptoms appear instead of when it completely fails, I would have qualified with my mileage. Not only is the repair costly, but for those who cannot afford it and need to continue to use their car despite the brake pump and ABS unit failure, risk their own and others safety when continuing to operate their vehicle.

Filed Sep 27, 2020 · Driver assistance · 100,000 miles · AL

I am facing many problems with my car lately; it over heats alot and suddenly the speed drops while the car is moving in a very dangerous highway and I can then hardly drive it to park it aside. A message started also to appear frequently "check hybrid system". I was informed by the official toyota agent in jordan (markazia) that this problems is caused by the invertor. However, they are denying that the invertor for this car was recalled, contrary to what the offical toyota website states when I enter the VIN. They also calim that they are obligated by the main office to offer a software update only.

Filed Sep 18, 2019 · Acceleration, Brakes · CA

The prius vehicles covered only by warranty enhancement zjb are suffering the same dangers from brake booster pump failures as those toyota covered safety recalls d0h and k0l. By excluding prius with defective brakes from d0h and k0l, toyota has left the owners to helplessly experience life-threatening brake failures or malfunctions before toyota will provide the replacement brake components needed to make the car safe. The law requires toyota to prevent the life-threatening dangers of this defect before brake failure occurs. Toyota's cost-cutting strategy is causing crashes. Injuries and crashes caused by the brake defect explained herein have been reported to the federal safety agency. Toyota's decision to provide post-failure repair reimbursement - instead of a preventative safety recall remedy - explains many of the crashes and injuries reported to the federal safety agency. Here is a list of relevant complaints from 10794873,10875685,10876015,10927047,11231660,11219354,11014878,11151142,10680404,10627821,11154835,10983408,10704553,10734278,11173353,11064519,10971881,11186947,10923921,10573591,11243249,10819439,10592400,10919990, 10851950,10855586,11240240,11197067,11193820,11173721,11156466,11144698, 11235210,10550179,11253950,11102264,11044156,11253725,10616134,10875625, 11231596,10584723,11207636,10749388,11014797,11203834,11203591,11193354, 11182610,11155778,11130742,11129946,11164336,10498096,11219901,11154783, 10598545,11228248,10547701,11110691,11164990,11222966,11207630,11192342, 11184751,11183661,11183178,11173804,11173173,11173044,11162242,11144888, 11139660,11121916,11088447,11080403,11061959,10984549,11073636, 11034572, 10870866,10929397,11104163 when the brake booster pump assembly fails in a prius vehicle excluded from d0h, c1256, c1253, c1252, c1391, u0293, and other dtcs indicating dangers and fmvss noncompliance are being stored.

Filed Jan 31, 2019 · Brakes, Driver assistance · 176,619 miles · SC · crash

The edr report clearly showed that the brake oil pressure changes did not correlate with the progressively increasing vehicle deceleration. The issue is occasional, rare and cannot be reproduced every single time. This leads to disparity in assumed braking distance from routine experience by driving the vehicle and actual braking distance at the time of failed braking which supposedly may be as a result of inverter issues that are responsible for exclusively regenerative braking at low (<50 MPH) speeds.