2010 Toyota Prius: ABS light or ABS activating

Filed Aug 27, 2026 · Brakes · CA

Component failed: Brake actuator and accumulator on a 2010 Toyota Prius. It is available for inspection upon request. Safety: ABS, traction, and brake lights turned on suddenly in the middle of rush-hour traffic, followed by a spongey, hard-to-press pedal. Braking distance and efficiency was greatly impacted, and driving to a safe turn-out was extremely dangerous as I feared the brakes would give out entirely at any moment. The problem has been reproduced and confirmed by a dealership. UNKNOWN. Requested an inspection by the manufacturer but their "Customer Support Program" for the brake actuator and accumulator expired 10 years after the car's production date. After speaking to both the dealership and corporate, they have informed me that there is nothing else they can do in regards to reimbursement or satisfying the complaint. The only symptom of the problem prior to failure was a periodic hissing noise coming from the brakes. When the car was brought in for the catalytic converter in late 2025, the dealership failed to diagnose any issue with the brake booster system at that time.

Filed Jun 4, 2026 · Brakes · CA

ABS light came on 6 months ago as well as ((!)) light. As soon as those lights came on, the brakes had an increased stopping distance and it became harder to get the car to come to a complete stop. I have seen a few Prius owners in my area also having the same problem with their Prius. For my car, the ABS light would come on, then turn off for 300 or so miles, then turn back on and stay on for about 300 miles. That has lasted for 6 months. I had almost gotten in an accident yesterday after getting brake lines fixed for 4th time, and we determine the actuator and accumulator are both bad. I have also seen a lot of Prius owners with the same code. Where I am at, my shop is quoting me $2300 for the fix in total. That is absurd.

Filed Mar 29, 2026 · Brakes · GA

There are issues with the brake. Many times the brake pedal goes down to the floor and it losses ability to stop. Apparently there is a common ABS actuator and Brake issues. Toyota will not address the issue

Filed Mar 12, 2026 · Brakes, Driver assistance · NE

i have have 2 problems, both was recalls, but this one they say expired in 2021 when i bought the car and toyota dealer didnt tell me had recall so i could fix it before it expired. there is a class action lawsuit in the brake booster, master cyclinder actuator abs pump fialing loosing brakes making grrr noises leaking all brake fluid out continously dangerous to drive can cause bad accident wreck since i drive down the hwy alot and this is the only car i have to drive, i also have dc inverter module /sensor that is killing off 3 batteries now that i installed in 3 months, and toyota dealers wont fix unless it shows error but its a recall so since problen should fix this recall but wont pay for it to fix it even though it a recall right now that is not expired. im upset 3 dealers wont do it unless then charge me to do it. when toyotal mfg take it to any dealer and they will fix free but no one will do it. toyota mfg needs to make these dealers fix these 2 recalls on this car that can kill me and my passengers and anyone on the road that i could hit by not haivng controll brakes or the hybrid system shuttong completely down and could even kill a pedestrian with these 2 recalls that dealers wont fix but mfg said they need to everyone with these cars i see are having these same problems. need make the toyota mfg and dealers fix these free of charge before more people get killed injuried or cause more accidents ,

Filed Dec 30, 2025 · Brakes · TX

On November 25, 2025, at approximately 11:45 p.m., our 2010 Toyota Prius experienced a braking system malfunction during normal operation. The brake pedal required significantly increased effort and the vehicle exhibited reduced braking performance, indicating a loss of brake power assist. The vehicle required increased stopping distance, creating an immediate risk of a collision. At the time of the failure, multiple warning indicators illuminated simultaneously, including the brake system warning, ABS warning, check engine light, battery warning, steering warning, tire pressure warning, and vehicle stability control/slip indicator. There were no warning lamps or abnormal symptoms prior to the failure. The failure was determined to involve the brake booster pump assembly, a component responsible for maintaining hydraulic brake assist pressure. This component is known to experience internal accumulator housing degradation, which can allow nitrogen gas migration into the brake fluid and result in partial or complete loss of brake assist. The affected component remains available for inspection. Following the incident, an authorized Toyota dealership inspected the vehicle and reproduced and confirmed the condition. Service records indicate the brake booster pump assembly had previously been replaced under a Toyota safety recall. Despite this prior recall repair, the same component failed again after approximately 41,000 miles of service, demonstrating that the recall remedy was ineffective. As a result of this failure, the vehicle was rendered unsafe to operate. Despite dealer confirmation that the malfunction involved a previously recalled safety component, corrective repairs were declined, with warranty limitations cited rather than addressing the repeat safety-related failure.

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 Dec 2, 2025 · Brakes, Fuel system · NC

The contact owns a 2010 Toyota Prius. The contact stated that while driving 70 MPH, the vehicle jerked, and the vehicle failed to accelerate as intended while depressing the accelerator pedal. Additionally, the steering wheel seized, and the vehicle stalled. The contact pulled over to the side of the road, opened the hood, and disconnected and reconnected the battery terminals to reboot the vehicle. The contact stated that a yellow triangle warning light and the check engine warning light were illuminated. The message "Check Hybrid System" was displayed. The contact was able to restart the vehicle; however, the vehicle failed to exceed 65 MPH while driving. The ABS warning light was illuminated. The contact took the vehicle to Auto Zone and O'Reilly's; however, no cause for the failure was found. The vehicle was then taken to the dealer. The contact was informed that the failure might be an ABS system failure. The vehicle was not repaired due to the cost. The contact stated that the failure first occurred years ago, and the failure persisted. The manufacturer was not notified of the failure. The failure mileage was unknown.

Filed Nov 3, 2025 · Brakes · 172,000 miles · TN

The contact owns 2010 Toyota Prius. The contact stated that while depressing the brake pedal, the ABS, brakes, and the vehicle stability control warning lights were illuminated. An Independent mechanic was contacted. The vehicle was taken to an independent mechanic where it was diagnosed and determined that the brake booster and accumulator needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure and informed the contact that the VIN was not included in the recall; however, the recall had expired. The failure mileage was 172,000.

Filed Oct 3, 2025 · Brakes · PA

One day after arriving home from work, all the sudden my ABS light, BRAKE light and traction control light turned on, my brake pedal being harder to push, and my car making weird humming noises every 5 seconds. Upon taking my 2010 Prius to my trusted repair shop, it was revealed that my break actuator was faulty. I drive on roads that need this part to WORK! Especially in the height of construction going on PA. One of the roads that I take has been milled up and upon driving on that road I nearly swerved onto the side walk 3 times! My breaking has been harsh and with one incident that nearly didn't break in time at all! Doing research and looking into the active investigations on this part, it turns out I am one of possible thousands who are dealing with this issue that has all been tied back to the break actuator being faulty which is very expensive to even repair for something that is obviously a poor design.

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 Sep 2, 2025 · Brakes · OH

The ABS, Brake, TSC lights have all appeared on the dash. When running the OBD codes, the error C1391 appears indicating a problem with the ABS pump. When under the dash with the vehicle running, one can hear the abs pump engaging every few seconds which is not normal. After resetting the code. The error quickly pops back up. This is a known problem with this model Prius that Toyota is aware of. Toyota has NOT put out a safety recall for this issue. They refuse to make the repair of a faulty designed abs module, which is obviously a safety concern. The vehicle currently has 128000 miles with no other issues.

Filed Aug 28, 2025 · Brakes, Electrical · OH

It is a known problem that Priuses manufactured from 2004 to 2015 have issues with the brake master cylinder and brake booster accumulator. When the vehicle computer recognizes an internal leak (ABS C1391) or other issue in the accumulator pump, it completely disables the regenerative braking system, which significantly reduces braking power. In my case, the problem is intermittent, and the vehicle computer will occasionally clear the code and operate normally. A slight whirring sound can still be heard (indicative of an internal leak), leading me to conclude that the part is still damaged, even when the code clears itself. This continues to affect my and my passengers' safety because the problem comes back with no warning while driving. Many times at highway speeds, the regenerative braking system will shut off while decelerating. This has caused scares and near-accidents. Imagine you are approaching stopped traffic while traveling 65 miles per hour. You press the brake to start slowing down, and while decelerating, the dashboard lights up and the brake pedal goes spongey. Now, you must slam the brake all the way into the firewall to engage the disks and pads exclusively. Aside from the imminent terror of hitting the car in front of you, now you are skidding on the brakes, worried the car behind you will crush the rear. Sooner or later this will cause somebody to get into an accident when a split-second decision cannot to be made quickly enough. The issue is well-known, and a warranty recall was issued, but it does not cover any vehicles over a certain age and mileage. It has been reproduced by my local mechanic and inspected by a Prius specialist, who both quote about $3800 to fully replace and recalibrate the failing parts. There were no indicators of this issue before it happened to my wife and I the first time on the highway. While I am grateful that nobody was injured, the situation could be completely different had the problem occurred just seconds later.