2010 Toyota Prius: soft or spongy brake pedal

Filed Dec 17, 2025 · Brakes · TN

Car keeps throwing a C1391 Abnormal Leak in Accumulator code. The ABS, traction control, and brake lights are all illuminated. Hissing sound from brake pedal. Spongy feel when braking and incredibly soft braking as well, very hazardous to driving and stopping. This is a known issue with the 2010-2015 Prius, and a quick internet search shows thousands of other Prius owners who also have this issue with their vehicles. It’s a safety hazard and can be potentially life threatening. Toyota is not doing anything to rectify this potentially fatal issue that impacts thousands of vehicles and vehicle owners and their families. Estimated cost of repair is upwards of $4,000 and simply not affordable to most consumers. Actions needs to be taken IMMEDIATELY by Toyota to recall these vehicles and fix them.

Filed Sep 4, 2025 · Brakes, Steering · TX

Have multiple warning lamps that light up on and off and the brakes in my car get spongy making the braking unsafe. The lights that turn on are the steering/ traction , brake, and abs light. There are multiple complaints online on YouTube from similar issues ongoing and no recall made. My mechanic says it indicates a leak however there is no brake fluid missing and on YouTube there’s work arounds because people keep getting the same message, yet no recall has been made. This can affect steering and cause an accident. Please recall soon. Including YouTube link so you can see all the comments and issues from thousands that don’t know how to report but view to fix temporarily. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed May 5, 2025 · Brakes · FL

Code diagnostic C1391 ABS system. I have replaced this in my previous 2009 Toyota Prius, it has been replaced in this 2010 Toyota Prius, and now needs to be replaced AGAIN in the 2010 Toyota Prius. It’s incredibly dangerous, no warning signs, spongy brakes all of the sudden that barely feel like they’re going to work. It puts not only myself in danger, but others especially when it just happens without warning and all of the lights come on as you are driving and the brakes become extremely wonky.

Filed Jan 24, 2025 · Brakes · CA

Abs lights on, traction light on .Actuator running cicle constantly . Breaks felt spongy

Filed Oct 29, 2024 · Brakes · 77,000 miles · FL

The contact owns a 2010 Toyota Prius. The contact stated while driving approximately 40 MPH and depressing the brake pedal, the brake pedal was stiff and required excessive force to depress. The contact stated that the ABS, Stabili-trac, and Parking Brake warning light was illuminated. Additionally, the contact stated that a chime sounded and could not be turned off. The contact stated that the failure had been intermittent but was a recurring failure. The contact had not taken the vehicle to a local dealer or independent mechanic. The vehicle was not diagnosed or repaired. The contact researched online and related the failure to the federal safety agency Campaign Number: 13V235000 (Service Brakes). The manufacturer was not informed of the failure. The failure mileage was approximately 77,000.

Filed Jan 11, 2024 · Brakes · KY

All the lights on my dash board came on suddenly, and the brake emergency, traction control and ABS lights stayed illuminated. Upon exiting the interstate I could not come to a complete stop at the end of the exit, which was very scary. Fortunately the cars driving on the road the exit merges into did, so we avoided a terrible accident. The brakes were spongy and not operating properly after that. The next day with all the lights still on, I slowly drove (20 mph) to the local Toyota Dealer , who claimed that error code (C1391) was being displayed and according to Toyota, that means the Booster is or will be leaking. Therefore the Pump and Booster needs to be replaced (estimated at $3K). No lights or errors were given before the incident, the brakes just suddenly malfunctioned. However Toyota apparently is aware that the booster and pumps fail without warning, because I discovered with an on-line search that code had a "customer extension" warranty (by googling the code C1391), I called customer service but they refuse to help. They claimed I was mailed a letter in October 2018 (they didn't offer to supply a copy.) However, I never received a letter or any notice from Toyota or the Toyota dealer that I have repeatedly used since I bought the car in 2010 (I have had brakes replaced there when it was under 150k and no one said anything!) Now they are stating that the extension has expired as it was only good up to 150,000 miles or 10 years which ever came first. I can't understand why they have a known brake issue and not replace the part when the vehicle is already at the dealer (It's there for every oil change 3 x a year!) Brakes are an important part of a vehicle, a failure like this should have been recalled, and Toyota should have been made to replace the faulty parts!

Filed Jun 10, 2022 · Brakes · AZ

I purchased my car in January 2010 within that first year I noticed that randomly if I hit a bump in the road and I would apply my brakes my car would do a wired skid and I couldn’t break properly. This has continued the entire time I’ve owned my car. Last month I was driving down the highway and ABS! Red brake light and ABS warning light all illuminated. As I was exiting the highway and applying the break I noticed my brakes were very spongy taking considerably more effort to stop. I started noticing a few months ago my breaks took considerably more effort stop and breaks felt spongier. The day my warning lights lit up a mechanic stated a code of C1391 was detected. Indicating break booster problems. the federal safety agency issued a recall Rep 13v235000 which is Break Booster my car was manufactured 10/09 so I understood my car was part of this recall but Toyota claims that is not a recall but a customer support program which has expired 2 years ago. I’m the original owner w/ 69,000 miles. Clearly my vehicle has and continues to have break issues so why is Toyota shirking responsibility and endangering me and other drivers allowing a car w/ breaking issues to not be properly repaired under the recall

Filed May 12, 2022 · Brakes · TN

The Traction control, ABS, and Brake light all came on simultaneously. It was random with no trigger. The brakes feel spongy, and will not regenerate to charge the hybrid system.

Filed Dec 27, 2021 · Brakes · TX

2010 toyota prius brake booster failure. according to multiple resources online, there have been known issues with this part from Toyota across multiple models. After recalling only a small portion of vehicles due to this failure, complaints have been filed with the federal safety agency to address toyota's lack of corrective action regarding the vast amount of vehicles utilizing this technology. this is a dangerous defect that caused my brakes to malfunction during a cross-country trip. my brake and ABS lights suddenly came on, and i could tell my prius handled differently. the brake pedal became hard to depress and stop time increased drastically. i am having a mechanic diagnose and repair this issue costing no less than $1200 in austin, TX. i would like to make a complaint to toyota for not recalling all the models with this issue and instead choosing to recall a minute fraction of potentially defective vehicles.

Filed Nov 16, 2021 · Brakes · TX

We have a 2010 Prius Purchased March 2010. Toyota issued a "Customer Support Program" (free extended warranty) for the brake booster and brakebooster pump assemblies in 2019. The Primary Coverage was offered until 11-30-19 regardless of milage. After that the secondary coverage applied for 10 years or up to 150,000 miles. The information mailed to us states; "If you have not experienced the condition described above, there is no action necessary at this time." We did not experience any brake problems until 11-10-21, when the dash display lit up with the BRAKE LITE, ABS LITE, SLIP INDICATOR LITE, AND THE ! LITE, ALL CAME ON AT THE SAME TIME. ALSO THE BRAKE PEDDLE BECAME SPONGY AND AT TIMES VERY HARD TO DEPRESS. We had our Toyota dealer run a diagnostic scan of the vehicle and they determined the brake booster and brakebooster pump were defected. The car has 70,000 miles on it at this time, and we have owned the car for 10 years and 8 months. Toyota will not honor this Customer Support Program since we are 8 months beyond the expiration date. There was a RECALL number 13V235000 issued 06-05-13 for the same exact problem, with NO EXPIRATION DATE. However, Toyota says it does not apply to our car. This problem causes the power brakes to not work as power, only manual brakes (Hard to Push). They also become very soft and not responsive if the engine has not run since the last time the brakes were pushed. THIS IS A DANGEROUS SAFETY ISSUE! ! ! My question is, the problem was a big enough to have Toyota issue this 10 year "Customer Support Program" to prevent a hazardous situation from being on the road for 10 years, why is it not hazardous NOW 8 months later? We welcome any help you can provide.

Filed Aug 24, 2020 · Brakes · 163,866 miles · TX

The red brakes light, ABS light and the 'yellow skidding car' icon lights all come on together, but intermittently. The brakes often feel difficult to press down upon starting the car. Ofter when the lights are on, the brakes feel spongy, or as though they may not stop the car. I took the car to the toyota dealership and they concluded that the master cylinder and other parts needed replacing. I found out that toyota has had lots of problems with these brake cylinders.

Filed May 14, 2020 · Brakes, Fuel system · 102,000 miles · CA

Toyota USA failed to honor repair defect within the brake booster pump assembly. When this defect occurs, various warning lamps on the instrument panel made illuminate, I experience increased stopping distance, reduced hydraulic pressure within your brake system, the deactivation of brake assist, & the deactivation of vehicle stability control.toyota previously issued at least 2 safety recalls. Designed to prevent similar dangerous occurrences. However, hundreds of thousands of prius models 2010-2015 were excluded from those safety recalls including my 2010 model. As of today toyota USA filed case number 2005052305. Safety recall in torrance california dated june 4, 2013 stated toyota sales USA was conducting a voluntary safety recall involving over 87,000 model 2010 toyota prius however I called toyota today and the insisted my vehicle was excluded even though in barely has 100,000 miles we just began to experience these brake symptoms. Customer rep insisted it was toyota voluntary recall not enforced so my vehicle did not even qualified for a customer support service. Please help us have toyota fix this safety issue asap before someone has a mayor accident. Warning lights for ABS, stability control, and warning lights all came on at once. Brakes became spongy when pressed. Was able to still brake but with much more effort and not confident in the braking. I had it towed to a local mechanic and the diagnostic error code registered "c1391". Per mechanic this is for ABS accumulator, or booster pump failure or leak per mechanic. This happened out of the blue, no warnings. Per toyota the part required are cylinder assembly brake and brake pump assembly. Cost to repair these parts per toyota would be estimated at $2700.. Attached video of actuator's loud noise it produces & dashboard showing ABS failed& brakes lights/also failed attempt to solve this with toyota USA.