2014 Toyota Prius: ABS light or ABS activating

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 Sep 12, 2026 · Brakes · CA

ABS and brake light are on. was on the freeway and when i pressed the brake the wheels got locked and the car made a 360 spin, it almost flipped over

Filed Sep 4, 2026 · Brakes · TX

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 the federal safety agency to consider whether continued C1391 brake booster/accumulator failures in these Prius vehicles warrant further investigation or safety action.

Filed Jul 17, 2026 · Brakes · CA

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.

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 May 28, 2026 · Brakes · CA

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.

Filed Apr 15, 2026 · Brakes · MD

On April 5, 2026, while driving downhill around a corner in my 2014 Toyota Prius, the brake booster and brake booster pump assembly failed without any prior warning. When I pressed the brake pedal the car did not slow down and instead appeared to accelerate due to a complete loss of braking assist. I was unable to stop the vehicle normally and had to rely on gravity and coasting to slow down, creating a serious risk of collision. There were no warning signs prior to the failure. Immediately after the incident, three warning lights illuminated on the dashboard: the BRAKE light, the ABS light, and the VSC (vehicle stability control) light, which have remained on since. The vehicle was taken to DARCARS Toyota Baltimore, 6007 Eastern Ave, Baltimore, MD 21224, where the failure was confirmed on April 15, 2026. Technician Victor Lawson diagnosed diagnostic trouble code C1391, which is the exact qualifying code listed under Toyota's Customer Support Program ZJB for brake booster and brake booster pump assembly failure (RO# XXX). The vehicle remains at the dealership and is available for inspection. Toyota corporate was contacted and opened case number XXX but declined to cover the repair despite this being a documented issue that Toyota has publicly acknowledged. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Apr 5, 2026 · Brakes · GA

While driving, three warning lights suddenly appeared on the dashboard . Abs warning, traction light, and break warning light At the same time, the brake pedal became very hard to press, and the vehicle did not slow down as expected. This caused a significant increase in stopping distance, and I nearly rear-ended the vehicle in front of me. The issue appears to involve the braking system and created an immediate safety risk. No prior warning signs were noticed before this incident. The vehicle has not yet been inspected but is available for inspection upon request.

Filed Mar 13, 2026 · Brakes · 152,000 miles · FL

The contact owns a 2014 Toyota Prius. The contact stated that while driving at an undisclosed speed, the vehicle failed to slow down as intended with the brake pedal depressed. The ABS warning light was occasionally illuminated. The vehicle was pulled over to the shoulder of the roadway and restarted. The vehicle was taken to a local independent mechanic, where it was diagnosed, and determined that the brake master cylinder, brake booster, and brake lines needed to be replaced. The local dealer was contacted; however, the vehicle was not diagnosed or repaired. Upon further investigation, the contact related the failure to an undisclosed recall; however, the VIN was not included in the recall. The manufacturer was notified of the failure. The contact was referred to the federal safety agency Hotline for assistance. The failure mileage was approximately 152,000.

Filed Mar 4, 2026 · Brakes · CA

Vehicle: 2014 Toyota Prius v Hybrid Mileage: 79,000 miles The vehicle experienced sudden failure of the brake booster / brake accumulator system. Multiple warning lights appeared including ABS, traction control, and the red brake warning light. Diagnostic code C1391 was retrieved. The brake pedal became soft/spongy and the electric brake pump began cycling frequently. Braking performance felt reduced and inconsistent, creating a potential safety risk. This vehicle has very low mileage (79,000 miles) and has been well maintained. The failure appears to be related to a known defect in the Prius braking system. Toyota previously issued Customer Support Program 20TE07 addressing brake booster and pump failures on 2012–2014 Prius v vehicles. Despite this known issue, the repair is not being covered and the cost quoted is several thousand dollars. A failure of the brake booster/accumulator system significantly affects braking performance and should not occur at this mileage. This appears to be a widespread issue affecting Prius vehicles and represents a potential safety defect involving the braking system.

Filed Feb 3, 2026 · Brakes · AZ

The slip notification, abs, and brake lights turned on while driving on the highway. The brakes then became very stiff and the vehicle did not brake as fast or as well as it normally does without the lights.