2014 TOYOTA PRIUS Complaints

While driving my 2014 Toyota Prius, the BRAKE, ABS, and vehicle stability/traction control warning lights illuminated. There was no crash, injury, or noticeable loss of braking before the warnings appeared, and there were no preceding symptoms. The vehicle was evaluated by Mac Haik Toyota in League City, TX, an authorized Toyota dealer. They diagnosed DTC C1391, “Abnormal Leak of Accumulator,” and determined that the brake booster and brake booster pump/accumulator assembly require replacement. The dealer advised that the vehicle cannot be driven and is considered down. The vehicle/components are available for inspection upon request. My safety concern is that this is a brake-system malfunction serious enough that an authorized Toyota dealer has determined the vehicle cannot be driven. Toyota previously established Customer Support Program ZJB addressing internal malfunctions of the brake booster and brake booster pump assemblies in 2011–2015 Prius vehicles. Toyota’s documentation specifically identifies C1391 as a diagnostic code associated with this condition. My Prius has only approximately 102,000 miles, well below the program’s 150,000-mile limitation, but is outside its 10-year time limitation. The Toyota replacement part required to repair the brake system is now backordered with no known timeframe for availability. Because Toyota has advised the vehicle cannot be driven, it will remain out of service until the part becomes available. I am reporting this because a previously identified brake-system failure continues to occur after Toyota’s support period expires. I ask NHTSA to consider whether continued C1391 brake booster/accumulator failures in these Prius vehicles warrant further investigation or safety action.

I am submitting this complaint regarding a serious safety concern involving the brake actuator/booster assembly on my 2014 Toyota Prius. My vehicle has experienced failure of this critical braking component and has been unable to be properly repaired since November due to difficulty obtaining the correct replacement parts. This involves a major safety system required for proper braking operation. Brake actuator/booster assembly. Diagnostic codes: B1206, B2321, C1252, C1253 C1256. Toyota previously acknowledged brake actuator concerns through Customer Support Program ZJB. However, my vehicle is outside the program limits despite experiencing what appears to be the same type of failure reported by many other Prius owners. Since November, I have faced difficulty obtaining the correct parts, reports of nationwide backorders or limited availability, conflicting information regarding updated Toyota part numbers, and concerns about repair providers advertising new OEM parts that may actually be aftermarket or incorrect components. This creates a safety concern because owners experiencing brake failures may be unable to obtain timely repairs using verified, appropriate parts. Repair estimates have ranged from approximately $3,000 to over $4,000, including a Toyota dealership estimate of approximately $4,100. This creates a significant barrier to restoring a vehicle to safe operation, especially involving a component Toyota has previously addressed through a customer support program. I request that NHTSA review this complaint and similar reports to determine whether further investigation is warranted regarding Toyota Prius brake actuator failures, parts availability issues, and whether additional manufacturer action or support is needed. A vehicle’s braking system is a fundamental safety component. Owners should be able to obtain a safe and reliable repair without months of delay or uncertainty regarding replacement parts.

In 2024, I had my vehicle checked out prior to a road trip because the brakes were making "fart noises," and I was worried about driving it to Albuquerque. The AAA certified dealer I took the car to said everything checked out alright. I never received the letter regarding the brake system issue, so I could not take advantage of the extended warranty repair program. My car was in the 80-90 thousand mile range and had not yet rolled over. Fast forward to 2025, my dashboard lit up all over the place, and I got the brakes checked again. By that time, the fault code was coming up, but the entire ABS system needed to be replaced. I was unable to get any help from TOYOTA despite this being a KNOWN FAULT WITH TOYOTA PRIUS AND TOYOTA PRIUS V FROM THIS TIME PERIOD. They are STILL not doing anything to help their customers. Brake issues are EXTREMELY dangerous, and it is wildly negligent to continue moving forward WITHOUT fully recalling the ABS system in the FULL LINE of prius vehicles from the impacted manufacture dates. Every prius owner I know has had to deal with this. My care was UNDER the required mileage but PAST the dates to be repaired. PLEASE consider holding TOYOTA responsible and getting them to refund Prius owners who have already paid for this COSTLY repair out of pocket. Thank you.

My car experienced a failing brake actuator/accumulator. The first sign was the ABS and break lights accompanied by a whoosing sound. The issue causes intermittent system wide break failure and renders the car undriveable. Toyota had an extended warranty for this issue but that offer was closed by the time my car had the failure even though it was still under 150,000 miles. I believe this is a significant safety issue and should rise to the level of a recall by Toyota.

Brake actuator had been making noises and it finally stopped working on 7/14/26. Thankfully my car was and stopped and parked. The car has 137k miles on it, one owner and no explanation of what caused this. There were no accidents, abuse, or failure to maintenance.

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.

I purchased a 2014 Toyota Prius V in 2013, and it currently has 120,000 miles on it. Last month, the engine light came on, so I took it to a dealership. They diagnosed the issue and provided the codes P0302 and P0304. After consulting multiple shops, all confirmed that coolant is leaking into the engine, which means I either need to repair the head gasket or replace the engine entirely. The quotes I've received for this repair range from $5,000 to $15,000, while the current value of the car is only about $5,000. I want to file a complaint regarding Toyota's responsibility for these engine issues. We buy cars because we trust the brand, and in this case, Toyota has broken that trust. Despite maintaining the car according to Toyota's recommended schedule, I have encountered this serious problem.

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 NHTSA that it is a common issue and quite dangerous, meaning the brake system is failing.

ABS, brake, and traction warning lights came on. Loss of power brakes/limited manual brake. Extended warranty/customer service outreach did not apply. Car is at 120,000 miles and almost 12 years.

When the brake is applied, the vehicle accelerates for a fraction of a second before slowing down. I have experienced this when the vehicle is moving slowly, such as in a parking lot.