ABS, Brakes, Traction control lights, and ! illuminated while driving car is under 150,000 miles. Took to an autoshop, Gerald's Tires and Brakes: was told Mastercylinder, booster, accumulator need to be replaced.

- North Charleston, SC, USA

The conditions listed in Toyota Customer Support Program ZJB for the brake booster and master cylinder occurred after the 10 year in service date on my vehicle. Brake, ABS, and Traction control warning lights turn on intermittently and when this happens brake response is poor and cruise control shuts off. When applying the brakes an audible tat tat tat sound can be heard from the front of the car that sounds like the ABS being triggered. You should have toyota recall impacted cars and fix the issue as outlined in the TSB and support campaign.

- Ann Arbor, MI, USA

The 2011 Prius has an issue known to Toyota, in which the brake booster pump fails after an indiscriminate amount of time, leading to significant loss in braking ability and control. Toyota knows of this because they issues an extended warranty coverage for these vehicles and this issue, that did not extend beyond 10 years, or 150,000 miles, whichever comes first. [XXX] ) When I was driving my car down Highway [XXX] I lost braking control completely, with a series of constant beeping starting to emit from the braking system. Luckily through mashing the brake pedal and using ebrake I was able to get the car to slow down and pull off the highway. The brakes sporadically and randomly cut in and out with the power braking, leading to uncontrolled stopping power and jerky or inactive braking. There had been lights on the dash indicating the traction system or braking system had issues but these would frequently turn off and on and didn't result in a loss of braking ability or performance and had been there a couple months. Upon taking the vehicle to a Toyota Dealership (Charles Maund North Austin) I was told it was a C1391 error regarding a failure of the brake booster pump assembly and that it would need to be replaced and reprogrammed for about 3300 dollars. After looking online I saw there were many other people with this issue, all who were unable to fix this in the given 10 year frame. Many unsuspecting second owners of this vehicle do not know that there is a hidden danger waiting for them when their power brake pump assembly fails. If I had been a less experienced driver I would've certainly crashed and Toyota, knowing of this safety concern already, should have done the right thing and issue a recall for these vehicles. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

- Austin, TX, USA

Brake warning lights came on, brake stopping has diminished significantly, throwing error codes, attached pictures of the error codes

- Vancleave , MS, USA

While driving the car I had three lights turn on the dash simultaneously. The parking brake light, traction control light, and ABS light. The brakes worked but felt spongy and not as responsive as normal. I had it checked out and it has code C1391. The recommendation is to replace the brake booster pump. I was quoted over $2,000 for the repair. There was a Toyota Customer Support Program ZJB that addressed this exact issue. It expired two years ago, and I am now stuck with the repair costs. I believe Toyota should have notified me of this potential danger and/or inspected the vehicle. I meet all the requirements of the bulletin, but it has expired. I reached out to Toyota, and they would not offer any assistance.

- Yucaipa, CA, USA

The brake system is constantly failing/malfunctioning.It is available for inspection upon request. There has been several incidents where other vehicles have nearly been rear ended. I took my 2011 Toyota Prius (hybrid) to Toyota approximately 8 months ago. They/Toyota did confirm that the problem was indeed the brake booster. The warning lamps did come on soon as the brakes started malfunctioning.

- Anderson, SC, USA

I have a 2011 Toyota Prius with 85K miles, as I was driving on the highway the abs light, brake light, and TSV light came on and then brakes were not working like normal. Had to pump the brakes very rapidly and steer off to the right side of the highway and use the emergency brake to come to a complete stop. I called the Toyota dealer and they said its the brake accumulator fault and they will not cover the fix because it was out of the 10year/150K mile warranty per SB. Towed my car to an independent service center and they confirmed it was the brake accumulator C1391 code. cost me $3000 to fix.

- Glendale , NY, USA

I-??ve been told by our machanic that our Prius-?? ABS braking system is malfunctioning.

- Saint Augustine, FL, USA

Brake ABS system dashboard lights warning system always always going off for the 9 years I've owned the car. Had the ABS system replaced and still the dashboard lights going off and the system not functioning properly.

- Marshfield, VT, USA

I have been experiencing intermittent brake issues with this car now for the last 50k miles. Sometimes the warning lights on the dash will activate, sometimes not when I am experiencing issues. the power assist is the problem. - it activates and then deactivates without warning instantaneously, while applying brakes or not. Sometimes when I am applying the brakes without the brake assist working, it will instantaneously start working without warning, causing my car to almost lock up its brakes. This is very dangerous, especially in traffic. When I apply my brakes at any given time, I never know if I am going to have power assist or not. I have replaced the brake master cylinder once already with a mobile mechanic and the problem went away for about one year but now it is happening again so this seems to be a reoccurring issue with this car. I have decided to just stop driving the car and bought a different one. I am a delivery courier and I cannot be driving a vehicle unsafe as this. I have reported the issue to my local dealership, but they are refusing to troubleshoot without charging me and it-??s telling me there are no recalls.

- Baytown, TX, USA

My brakes were making noise since month, now the ABS light turn on.

- Los Angeles , CA, USA

The ABS, anti-skid, and brake lights came on. Immediately, the brakes were less than full stopping power, and it was obvious it was not safe to drive the car any further. We had noticed that a pump was being activated when the brakes were being used, but no service codes were being displayed when checked. We later found out there was a recall on the Brake Booster and Accumulator, but it was only a limited recall, no notice was sent to us, and no repair was authorized by Toyota unless the brakes completely failed. Once the dash warning lights came on, the C1391 service code appeared when checked, "Abnormal Leak of ACC Pressure". This issue is a safety matter because your brakes fail instantaneously at any moment while driving.

- Youngstown, OH, USA

Traction control, ABS and Brake warning lights came on while driving. Car is now at the dealership for complete replacement of power pump and master cylinder assembly at a cost of $3,300

- Fishers, IN, USA

Brake booster and brake booster pump assembly are faulty and failing. Brakes are still functioning, but will ultimately fail without warning, from what I have read. This is highly dangerous for myself and other motorists. I was driving last week and tried coming to a stop at an intersection. I pushed the brake pedal and the car hesitated and then jumped/lurched forward before coming to a complete stop. The brake booster is sounding every 30 to 45 seconds to try and build back the pressure it is losing. Toyota offered a "Customer Support Program" for these parts, as there's been numerous premature failures. Unfortunately, my vehicle no longer fits within the parameters of the support program (see attached). From what I've read though, Toyota has been negligent with replacing the brake booster under the support program. I have called Toyota Corporate and they have offered no reprieve and won't stand behind this faulty part. Toyota needs to be forced to recall these 3rd gen Priuses and ordered to replace the breaking system. Expecting customers to shell out between $2-3k to have the ability to safely break/stop their vehicle is ridiculous, especially when Toyota is more than aware of this issue. I was quoted $2600 over the phone to remedy the issue from an independent hybrid shop. I've owned 7 Toyotas and two have been Priuses. This 2011 is by far one of their worst to roll off the assembly line with numerous reports of breaking problems, oil consumption issues, and head gasket failures. They need to stand behind their product(s), especially to brand loyal customers. Read more complaints about the breaking system: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

- Berea, KY, USA

Dear Mr; I own a 2011 Toyota Prius, and this week my brakes failed while driving down the highway. The ABS and Break lights and the ESP warning light on the instrument panel come on. The brake pedal is hard and has an intermittent hum in the engine area. The scanner gave the code C1391 / ACC PRESS abnormal leak error. I want to file a formal claim against Toyota for the failure of my car's brake system and request repair/replacement of my car's brake system. --------------------------------------------------------------------------------------------------------------------------------------------- What component or system failed or malfunctioned, and is it available for inspection upon request" BRAK SISTEMS / YES, IS AVAILABLE FOR INSPECTION. How was your safety or the safety of others put at risk? IT WAS DIFFICULT TO BRAKE / THE CAR WAS DEVIATED WHEN APPLYING THE BRAKE / I LEFT THE ROAD DUE TO THE RISK OF A COLLISION BY NOT HAVING THE ACTIVE BRAKING SYSTEM. Has the problem been reproduced or confirmed by a dealer or independent service center? YES / INDEPENDENT SERVICE. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? NO. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear"

- Cutler Bay, FL, USA

All of a sudden, a few weeks ago, the ABS, TRAC, BRAKE, and brake warning lights all illuminated on my 2011 Toyota Prius, and the brakes became hard to press. Turns out, this is a known issue with this model of the Prius. DTC C1391 stored in the ECU. There is a defect with the brake booster/brake booster pump, and Toyota issued a Customer Support Program to extend the warranty on these two parts, but the program ended in 2021 and I am just now having this issue, although my Prius only has 115k miles. This should be a recall. I should not have to pay more than $3500 at the Toyota dealership to get this replaced when it is a defect with the parts that Toyota made (I should not have to pay ANYTHING). No dealership in the area wants to honor it either. Instead, they want to charge me $3500. And when I called Toyota Corporate, they brushed it off and told me "the program expired a whole 2 years ago" without even trying to work with me on the cost of the repair or anything. Complete let down from Toyota.

- Glen Allen, VA, USA

Brake actuator failed. Noise when applying brake but no code or dashlight. Looks like a common problem across prius 2011 model cars

- Flowermound, TX, USA

The brake actuator on my 2011 Prius failed. Toyota issued an extended warranty of 10yrs/150k miles because they knew there was a problem with the product. I have less than 80k miles on my car and the actuator failed. I feel like I am being penalized because I don't drive my car as often. I contacted Toyota and was dismissed by them because I was outside of the 10yr window. The repair was $1737.98 in parts and $780 in labor by a Toyota certified technician.

- Decatur, GA, USA

The contact owns a 2011 Toyota Prius. The contact stated while driving 50 MPH, the check engine, service brakes, ABS, and the traction control system warning lights were illuminated. The contact parked the vehicle on the side of the road for approximately 3 minutes before continuing to drive to her residence. The contact stated on March 17, 2023, while her husband was approaching a traffic light, the brake pedal was depressed but failed to stop the vehicle properly. The contact stated that several warning lights were illuminated. The driver stated that the vehicle cruised to a stop independently. The driver decided to drive at a slow speed to the residence. The contact took the vehicle to the local dealer, where it was diagnosed and determined that the brake master cylinder, the brake pump assembly, and the brake booster needed to be replaced. The vehicle was repaired. The manufacturer had been informed of the failure. The failure mileage was approximately 159,000.

- Farmingville, NY, USA

Three lights appeared on the dashboard-??code C1391. This has affected the braking system, and the traction control-??and the brakes no longer regenerate the battery. The mechanic said -??YOU MUST NOT DRIVE THIS CAR-?? until a $2,700 repair is made. There was, apparently, a service bulletin sent out in 2019, and was then extended until 2022-??which we did not receive, although we-??ve been at the same address since we bought the car. But our car did not develop this common issue until now-??2023, and Toyota says it was not a safety recall, so they don-??t need to fix it, or help us get it fixed. We believe it IS obviously a safety issue-??.since my brakes can go out at any moment.

- Franklin, TN, USA