Owner-reported complaints naming the driver-assistance system, filed with NHTSA
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Reports naming forward-collision avoidance, lane keeping, back-over prevention, cruise control and related electronic driver-assistance systems. Every record below is an owner-reported complaint about the 2011 Toyota Prius submitted to NHTSA — not a confirmed defect, not a recall and not a manufacturer bulletin. 49 reports on file name it.
Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.
The 25 most recent of 49, in the owner's own words
2011 Prius. 80k miles. Brake booster buzz coming on every 15 seconds now. ABs, traction and brake lights on. I’ve heard of many Prius owners with the same issue. I also have another Prius with the same issue at 120k miles. Brake booster accumulator codes popping up with 80k miles. It is a safety concern as the abs brakes don’t work. Almost every Prius is effected by this.
I was driving my car and suddenly the traction , hand brake and ABS sign started showing up. I usually apply only 10% of force on brake pedal but after this I have to apply almost 60% of force to even slow down the car. Almost 90% force to stop the car It has threatened safety of my family. When diagnosed at autozone they told cannot determine error code. When reading in internet this seems to be common problem in prius. Please help is fixing the issue as it is not at my fault. This seems to be manufacturing defect.
Our trac abs and brake lights came on and braking became more difficult but not totally gone. I took it to my mechanic (not Toyota dealer) and he said the codes were going off for the abs hydraulic system and it would be $3000 to fix! This is unacceptable. I feel like my safety is affected but no one else has been hurt YET. I’m trying to be proactive. they first appeared last month. No manufacturer, insurance agent or cop has inspected it. It can be inspected by appt. Please help
Brake warning came on and wouldn’t go off. Followed by continuous beeping and now the brakes are no longer working properly. You have to force the brake all the way to the ground to even come to a rolling stop. The problem first occurred on 3/8/25. The brake actuator seems to be a reoccurring problem that Toyota addressed but is no longer fixing. It is dangerous to drive my vehicle and others have said their brakes have completely failed when this problem arose.
The contact owns a 2011 Toyota Prius. The contact stated while her husband was driving approximately 40-50 MPH and depressing the accelerator pedal, the accelerator pedal failed to go back to the normal position and remained stuck. There was no warning light illuminated. The contact's husband depressed the brake pedal, and the engine revved significantly. The driver was able to pull to the side of the road. The driver turned off and restarted the vehicle, and the vehicle responded as needed. The dealer was notified of the failure and referred the contact to the manufacturer for assistance. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure, but no assistance was provided. The failure mileage was approximately 119,000.
I was driving the vehicle around 55 mph when a check hybrid system warning popped up. About 30 seconds later the vehicle went from being in drive to B (brake mode) and the vehicle began to slow at a rapid pace with no warning. Could potentially cause an accident as this occurred with very little warning.
See attached document for complaint
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.
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)
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.
BREAK ACTUATOR IS FAILING IN MY 2011 TOYOTA PRIUS. THE CAR NOW HAS A UNPREDICTABLE ABS BREAKING SYSTEM. SOMETIMES THE BREAKS WORK AND SOMETIMES THEY QUICKLY FAIL AND A ERROR LIGHT COMES ON. THE LIGHT THAN GOES OUT AS IF NOTHING HAPPENED AND ALL IS FINE. THIS IS A VERY DANGEROUS PROBLEM THAT WILL LEAD TO MANY ACCIDENTS BECAUSE THE VEHICLE TELLS YOU ITS GOOD TO GO, MEAN WHILE THE ABS SYSTEM IS FAILING TO STOP THE VEHICLE INTERMITTENTLY. I AM SCARED BECAUSE I DONT KNOW IF THE CAR WILL DO THIS ON A TURN THEN LOSE CONTROL INJURING MYSELF AND OTHERS.
A CHECK HYBRID SYSTEM ALERT CAME ON AND INCLUDED LIT BREAK, CHECK ENGINE, STEERING, ABS, SKID AND YELLOW TRIANGLE WITH AN ! MARK INSIDE. THE CAR STOPPED AND I COULD NOT MOVE IT. GOOD THING I WAS ON A SIDE STREET WITH LIGHT TRAFFIC. THIS HAPPENED AGAIN AFTER THE INVERTER WAS REPLACE; AND IT HAPPENED AGAIN AFTER THE 12 V BATTERY WAS REPLACED.
BRAKE LIGHT, ABS,SLIP INDICATOR,BRAKE SYSTEM WARNIG LIGHT SYSTEM ALL CAME ON WHILE DRIVING AT HIGH VELOCITY [75M/H] IN THE RAIN AND LOST 75% OF THE BRAKING POWER PLUS THE CAR STARTED TO SLIDE. NEEDLESS TO SAY THIS WAS A CATASTROPHIC FAILURE OF THE ENTIRE BRAKE SYSTEM ON A CAR THAT HAS A CUSTOMER SUPPORT PROGRAM NOTIFICATION FROM TOYOTA[ZJB] THAT WAS SENT TO ME WITH A WARNING OF SUCH OCCURRENCE. THIS IS DOWN RIGHT IRRESPONSIBLE TO A MAJOR CAR MANUFACTURER TO ALLOW THESE VEHICLES ON THE ROAD WITHOUT TESTING THE ENTIRE SYSTEM ON EACH OF THESE AFFECTED VEHICLES AND WITH FOR A CATASTROPHIC FAILURE TO OCCUR AND CAUSE PUBLIC HARM OR EVEN DEATH. I HAD JUST TAKEN THE VEHICLE FOR SERVICE A FEW WEEKS PRIOR WHERE I EXPLAINED THE SERVICE ADVISOR OF AN ISSUE WITH BRAKE PULSATION. HOWEVER, THE ENTIRE BRAKE SYSTEM WAS NOT THROUGHLY CHECKED AND WAS JUST TOLD THAT ITS THE FRONT ROTORS THAT ARE UNEVEN, THANK GOD I DID NOT FULLY LOOSE CONTROL OF THE VEHICLE AND CAUSE A CATASTROPHIC ACCIDENT AS IT WOULD HAVE RESULTED IN BODILY HARM TO MY FAMILY. I EXPECT THIS FEDERAL GOVERNMENT AGENCY TO USE IT'S AUTHORITY TO PREVENT SUCH OCCURRENCE TO THE TAX PAYING CITIZENS OF THIS NATION.
TRACTION CONTROL, ABS AND BRAKE LIGHTS CAME ON TODAY AND BRAKE PRESSURE DROPPED SEVERELY WHILE DRIVING ON THE HIGHWAY. NOT SAFE TO DRIVE.
MY 2011 PRIUS VERY RECENTLY HAS STARTED MAKING AUDIBLY NOISE WHILE PRESSING THE BRAKE PEDAL, WHETHER IN MOTION OR STOPPED. THIS NOISE CONTAINS CONTINUOUS WHIRRING, WHINING AND LOUD CLICKING NOISE. THESE NOISES WHERE NOT SEEN BEFORE COMPLETELY. I SPOKE TO DEALER MENTIONING A TSB PERTAINING TO THIS PARTICULAR ISSUE IN SPECIFIC AND WAS TOLD NOTHING CAN BE DONE UNTIL IT FAILS COMPLETELY, WHICH IS BAD, AS I HAVE A FAMILY OF 3 AND GOD FORBID IF THIS WERE TO HAPPEN WHILE DRIVING ON FREEWAY, A SERIOUS SAFETY HAZARD AND TOYOTA DEALER (RUDY LUTHER) RESPONSE IS IRRESPONSIBLE. I AM ACTUALLY WORRIED MORE NOW ON WAITING FOR THE BRAKES TO FAIL. THIS LOUD CONTINUOUS CLICKING NOISES OCCURS THE MOMENT CAR IS TURNED ON AND THE NOISES LINGERS ON FOR SHORT WHILE AFTER THE CAR IS TURNED OFF, AT MOMENTS I HAVE TO PRESS ON THE BRAKES REALLY HARDER THAN USUAL TO GET THE CAR SLOWED AND IS A TREMENDOUS PANICKY SITUATION. I AM REGISTERING AND REQUESTING FOR THIS TO BE LOOKED IMMEDIATELY BEFORE ANY CATASTROPHE.
BRAKE LIGHT, ANTILOCK LIGHT, VEHICLE STABILITY LIGHT, AND YELLOW TRAINS CAME ON. HAVING PROBLEM WITH BRAKING. DOES NOT NOT SEEM TO BRAKE AS GOOD. IT IS VERY DANGEROUS WHEN DRIVING.
WELL I WAS DRIVING AND SUDDENLY MY CAR BATTERY TURNED OFF AND CHECK HYBRID SYSTEM CAME ON THE DASHBOARD IT STOPPED SO I PARKED IT ON SIDE AND UNPLUG BATTERY WIRES SO IT START WORKING AGAIN THE WEIRD THING IS THAT WHEN I CHECK TO SEE ANY CODE BUT NOTHING CAME RECENTLY IT WAS HAPPENING AND ONE RECALL CAME FOR HYBRID BATTERY AFTER THAT IT WAS WORKING FINE BUT NOW THIS THING HAPPENED AGAIN AND IT WAS DANGEROUS BECAUSE I WAS IN THE MIDDLE OF HIGHWAY AND CAR STOPPED.
WHEN BREAKING AND STILL MOVING, THE CAR WILL ACCELERATE MOMENTARILY RESULTING IN GOING FASTER FOR A SECOND OR TWO. THIS HAPPENED RANDOMLY OVER THE YEARS AND MAY IN SOME INSTANCES BE RELATED TO HITTING AN IRREGULARITY IN THE ROAD, BUT I CANNOT BE SURE. IT HAS NOT CAUSED AN ACCIDENT, BUT IS STRONG ENOUGH THAT IT COULD. I'M A PRETTY SAFE DRIVER SO TEND NOT TO RIDE ON THE TAIL OF THE CAR IN FRONT OF ME. I HAVE NOT KEPT TRACK OF WHEN IT HAPPENS.
THE CAR STOP WORKING ALL THE DASH LIGHTS STOP WORKING ,THE BRAKES START GETTING HARDER AND THE DON'T STOP AT ALL AND BEEPING WITHOUT STOP THAT NOISE AND THE HIBRYD SYSTEM STOP WORKING AFTER I LIVING FOR SOME RECALLS REPAIRS AND THE WANT ME TO FIX THE CAR TO PAY AND I KNOW IS NOT MY FAULT EVERYTHING IS BECAUSE IS THIS CAR IS ALL ELECTRONIC SYSTEM.NEVER ON MY LIVE I HAVE THIS PROBLEM WITH MY OTHER CARS.ONLY WITH THIS ONE AND NOW THEY ONE ME TO PAY FOR SOMETHING THE COMPANY MAKES WRONG.THIS IS NOT FAIR AT ALL.BEFORE I WAS RECOMENDED THIS CAR BUT RIGHT NOW PEOPLE ASK ME AND I HAVE TO TALK NEGATIVE SITUATION ABOUT IT.
THE CAR STARTS AS NORMAL AND DRIVES NORMALLY BUT ONCE YOU START TO COME TO A STOP THE CAR SHUTS OFF AND WILL ONLY RESTART WHEN YOU DEPRESS THE GAS PEDAL BUT SHUTS DOWN AGAIN WHEN YOU RELEASE THE GAS PEDAL, NORMAL CITY STREETS AND HIGHWAY
DRIVING VEHICLE DOWN HIGHWAY, TAPPED BRAKES BUT BRAKES DID NOT WORK, ALL THE LIGHTS ON MY DASH LIT UP. I LOST TRACTION IN BRAKES CAUSING VEHICLE TO LOSE CONTROL.
GOT IN CAR ONE MORNING AND ALL THE BRAKE / TRACTION CONTROL SYSTEM RELATED LIGHTS ARE ON. TURNED CAR OFF, WAITED 10 MINUTES RESTARTED CAR AND LIGHTS ARE STILL ON. TESTED BRAKE FUNCTION IN YARD, REDUCED BUT STILL ABLE TO GET CAR STOPPED. TOOK IT TO SHOP AND READ CODES, CAME BACK AS THE ACTUATOR WHICH IS ALREADY RECALLED ON PREVIOUS YEAR MODEL PRUIS', OBVIOUSLY THEY DID NOT FIX THE ISSUE ON THE EARLY GEN 3 MODELS (2010 & 2011). I HAVE FOUND MULTIPLE OTHER PEOPLE WITH GEN-3'S THAT HAVE HAD THE SAME ISSUE OS THESE SHOULD BE INCLUDED IN THE GEN-2 RECALL BECAUSE THEY ARE HAVING THE SAME ISSUE. WITH IT BEING A DEALER ONLY PART AT $4500-$5000 (PARTS AND LABOR) TO FIX ON A CAR THAT'S ONLY WORTH ABOUT $10,000 I WONDER IF IT'S REALLY WORTH FIXING. AT THIS POINT THE CAR IS PARKED BECAUSE WITH THE DIMINISHED BRAKING PERFORMANCE I DON'T FEEL SAFE DRIVING IT.
BRAKE ACCENTUATOR FAILED - NO WARNING AND TRACTION CONTROL/BRAKE LIGHT/ABS WARNING LIGHTS ALL ILLUMINATED. HARD BREAKING TEST @25 MPH CONFIRMS ABS NOT WORKING (I.E. TIRES SKID) AND BREAKING DISTANCE ADVERSELY IMPACTED FOR NORMAL BRAKING. HYBRID SYSTEM CHARGING FROM BRAKING IS DIMINISHED.
THE TRACTION CONTROL, ABS LIGHT AND WARNING LIGHT ALL CAME WHICH I BELIEVE ALL TO BE A SAFETY ISSUE
IN MOTION WHILE ACCELERATING PAST A SLOWER CAR. HEARD AND FELT A PRONOUNCED THUMP AND LOST ENGINE POWER ON BUSY LOCAL THOROUGHFARE. MOVED TO A TURN LANE AND STOPPED. MULTIPLE DASHBOARD LIGHTS AND "CHECK HYBRID SYSTEM" ON LED DISPLAY. POWER OFF CAR, AND BACK ON TWICE AND GOT THE SAME ERROR ON DISPLAY. FOUND THAT CAR COULD MOVE ON EV POWER AND I GOT IT INTO A SAFER LOCATION AT AN ADJACENT PARKING LOT. HAD VEHICLE TOWED TO REPAIR FACILITY. AS A DRIVER THIS WAS DISCONCERTING AS I COULD NOT CLEARLY DETERMINE IF THE CAR WAS AT ALL DRIVEABLE. IF A DRIVER WERE TO STOP IMMEDIATELY IN THE SAME SITUATION THEY WOULD BE ON THE ROADWAY. IF I HAD NOT PRESSED ON THE ACCELERATOR PEDAL AFTER POWERING ON THE CAR AGAIN I WOULD NOT HAVE KNOWN I COULD MOVE THE CAR TO A SAFER LOCATION. DISPLAY SHOULD READ "HYBRID SYSTEM FAILURE" THEN "LIMITED EV POWER AVAILABLE" THEN "MOVE TO SAFE AREA IF NECESSARY" CAUSE: HYBRID INVERTER FAILURE. REPAIRED BY TOYOTA UNDER 2014 EOE AND NEW 10/2018 RECALL J0A
Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.
Categories with enough reports to have a page of their own
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