2012 Toyota Prius: soft or spongy brake pedal

Filed Oct 1, 2026 · Brakes · FL

When I started my car this morning, the red BRAKE light, ABS warning light and anti-slip light were all illuminated. The car does still stop but the brakes are very spongy and there's a clicking noise under the hood. I only moved the car out of the driveway to allow other cars to leave. The brake fluid is not low. This is the problem listed under Toyota's Customer Support Program Notice ZJB but it is past the coverage expiration date. There should not be an expiration date on a known manufacturer issue. If this had happened while I was on the highway driving to work, I could have had a serious accident.

Filed Dec 25, 2025 · Brakes, Electrical · NY

While driving, the vehicle experienced a sudden brake system malfunction without prior warning or gradual degradation. The vehicle was being operated under normal driving, road, and weather conditions. No recent brake service, repairs, or aftermarket modifications had been performed prior to the failure. Multiple warning lights illuminated on the dashboard, including the ABS warning light, brake warning light, and traction control warning light. Shortly after the warning lights appeared, the vehicle began emitting continuous warning beeps. Audible buzzing or pumping noises were also present from the brake system during the malfunction. During this event, brake performance was reduced and braking felt inconsistent. The brake pedal became hard at times and spongy at other times, requiring increased effort to slow the vehicle and resulting in unpredictable braking response. This created a safety concern while the vehicle was in motion. The driver was forced to alter driving behavior and exercise extreme caution due to reduced braking confidence and unpredictable pedal feel. The malfunction has occurred intermittently during normal driving. The condition temporarily resolves on its own and later reoccurs without corrective action. The suspected failed component is the brake actuator / ABS actuator assembly. A diagnostic scan retrieved fault codes C1252 (Brake Booster Pump Motor ON Time Abnormally Long), C1253 (Pump Motor Relay Malfunction), and C1256 (Accumulator Low Pressure), which are consistent with brake actuator malfunction. The failure occurred at approximately 154,000 miles. This vehicle model and generation have a documented history of premature brake actuator failures with similar safety-related symptoms reported by other owners. The condition places the driver and others at risk due to unpredictable braking behavior, reduced braking effectiveness, and repeated warning alarms while driving. Warning lamps and audible alerts continue intermittently.

Filed Apr 29, 2025 · Brakes · FL

My brakes began making a funny noise when I used them. I only have 80000 on the car and do regular maintenance. I took it in because it seemed the brake pedal was getting spongy as well. They ran in through diagnostic tests and determined the braking module or brake booster/master assembly was bad. This seems to be an issues with Toyota and should be addressed immediately. It is an expensive fix for a low mileage car

Filed Jul 5, 2024 · Brakes · CA

In 2019, I took my Prius in for service. I reported that when I suddenly brake, the pedal feels spongy as if the brakes will not stop vehicle and lights on dash lit up. Toyota did diagnostic, no action taken by service department at Toyota dealership. I have service history documentation. On June 29, 2024 we had routine maintenance and the service department of the Toyota dealership recommended brake fluid serviced. On July 1, 2024, I was driving my child home from his summer camp and when I tried to stop the brake did not work. I started pumping the brakes several times until the car slowed and came to a stop. The lights on the dash lit up again. The brake failure put my son and I in danger. We had the car towed to the service department of the Toyota dealership. The service department sent the following information after their diagnostic. "The warning lights re-appeared after we drove it a few times. Now regarding the brake fluid service we performed, it is not related to those warning lights. Your accumulator is internally failing. The accumulator is a computer that distributes and controls the amount of pressure going into the brake system, and the computer was not untouched. Unfortunately it was bad timing and the computer started to internally fail. These vehicle's are known to have bad brake actuators, and Toyota created a type of recall for it to get replaced under no charge. Unfortunately they only cover up to 10 years and your warranty expired last year." My husband and I did not receive information regarding this recall. We did an online search to find out more about this recall and found several pages and posts of people describing the same situation.

Filed Jan 9, 2023 · Brakes · VA

Toyota Program ZJB, internal malfunctions of the brake booster assemblies. A known failure of the brake booster than Toyota did extend the warranty on for 10 years BUT would not honor the warranty unless specific diagnostic codes appeared on the vehicle. My issue is that all of the symptoms of the failure occurred on my vehicle (pump constantly running, varying hydraulic pressure resulting in pulsing brake stops, soft brake pedal) but the warranty would not be honored because the diagnostic did not manifest itself. Had technicians tell me that it definitely was this booster failure, but Toyota would not pay for it unless the diagnostic came up. I am now left with a vehicle that has a failed brake system and no monetary support from Toyota. Quoted $2500 to $3000 to repair. Not safe to drive in my opinion with a known failure that I am having trouble getting funding to repair. Contacted Toyota customer support and they reiterated that they would not pay for the repair without the diagnostic occurring and now their extended warranty expired August 31, 2021. Inspection available upon request Safety issue as braking is inconsistent and not predictable Problem was identified by Toyota dealer service department No diagnostic alarms - which is the only symptom not present

Filed Nov 27, 2022 · Brakes · SC

At 106K miles and after 10 years and 8 months in service (new vehicle bought in March 2012) Brake booster internal leak, code c1391. Brake light, ABS light and VSC light stay on. Can not drive it as the brake booster internal leak is making the brakes spongy and slow in response. Talked to Toyota and they said it is out of warranty and the deal is estimating $2000 plus for the repair. Miles on my cars 106K are way less than 150,000 allowed by Program Service bulletin ZJB (attached) but Toyota is denying repair coverage as the vehicle life is eight months more than 10 year limit since first use. Did not drive it much within the last two years because of working from home due to covid 19. Had it been driven more frequently the brake system failure would have happened way earlier as the internal leak (possible fatigue failure causing leak) should be more related to driven miles and brake system cycling of pressurizing and depressurizing than just being parked on the drive way. Would request if the federal safety agency could extend the duration of ZJB bulletin considering the fact that many drivers did not drive that much in the last two years due to working from home and this internal leakage failure can be related to fatigue loading of the hydraulic components and the number of fatigue cycle are directly proportional to the driven miles and not the life of the vehicle. Thanks

Filed Feb 1, 2022 · Brakes · 192,000 miles · LA

The contact owns a 2012 Toyota Prius. The contact stated that while driving at 30 MPH, the ABS, traction control, and several other unknown warning lights illuminated on the instrument panel as the brake pedal became spongy. The contact initially drove the vehicle to an independent mechanic who informed her of a service bulletin related to the failure; he then instructed her to take the vehicle to the dealer. The vehicle was taken to the dealer and the contact was informed that the vehicle could not be covered under a warranty related to the failure. The manufacturer was also notified of the failure and confirmed that her vehicle was no longer covered under warranty; a case was filed with the manufacturer. The contact agreed to have the vehicle repaired by the dealer and the vehicle remained in their possession. The vehicle had yet to be repaired. The failure mileage was approximately 192,000. The VIN was not available.

Filed Oct 16, 2021 · Brakes · FL

I write to report that I asked for help at TOYOTA on the repair of the brake booster pump program. On August 19th, 2021 I took my Toyota Prius 2012 to my nearest dealer, in this case, Toyota of Homestead in Florida, US (I have a screen capture of the appointment); because the brake pump was pumping continuedly every 15 seconds regardless of the vehicle was in motion or stop parked; also the breaking felt like spongy and hesitant. I explained that to the Toyota dealer employee and he told me that the pump running every 15 seconds is not normal and agree that something was not right with my car's brake, but if there is not a MIL light ON, they can not replace my brake booster under the Toyota Program, and I have to pay $170.-first to "scan" the vehicle and make a diagnostic, well I told him that was too much money just to scan the vehicle since there was no light on in the dash the Toyota employee told me I will need to pay for the full brake pump replacement. That was unfair because the Toyota employee agree that definitely the brake was bad, but can not do anything. Took my car home and a few days later September 2nd, the brake lights came on. Well, my wife uses this car daily to transport our kids to school and to do the shopping necessary for food and supplies, and definitely, the cars do NOT break AS IT SHOULD. Toyota employee told me the repair will cost between $3000.- to $4000.-, I took the car to the Dealer when was covered under the Customer Support Program, but the light on the dash should NOT be the main factor to determine that the brake booster needs to be replaced. To be fair TOYOTA should recall all those vehicles. The Toyota dealer employee witness that there was a problem with the pump, and anybody with common sense that know this cars should immediately notice that the sound of the pump going on every 15 seconds is NOT NORMAL. This is my second Prius (My first one was a Toyota Prius C 2014) and I detect almost immediately with something is WRONG.

Filed Jun 1, 2021 · Brakes · FL

The brakes felt very spongy and the car was having a difficult time coming to a complete stop. The ABS, brake, and stability control lights turned on at the same time. Also, a whirring noise close to the passenger side started happening every 2-3 seconds. After some research I later learned that the noise is most probably coming from a brake pump assembly that has failed and is not able to keep pressure. The car is currently parked since I don’t feel safe to drive it. I contacted a local dealer to see if this part can be changed for free since this is not normal wear and is unsafe. I also learned in online Prius owner forums that there is a large group of Toyota Prius owners with the exact same issue.

Filed Oct 2, 2019 · Brakes · 151,000 miles · MD

I started my car and my dash lights for brakes, anti-lock, anti-skid came on and brakes became spongy. This happens intermittently. I parked the car and later checked the lights and the car was operating normal. I drove the car around the neighborhood to try to duplicate the issue. Could not duplicate. The next day I started the car the lights came on again and brakes were not operating normally. Spongy and no anti-lock. I checked recalls and found the issue was recalled in 2010. I also found numerous complaints on prius forums for this issue covering 2012 prius. I think this is a safety issue toyota should recall for 2012 as well.

Filed Apr 25, 2019 · Brakes · 200,000 miles · TX

I having a problem with the brake booster on my prius and the toyota dealership I went to said I need to replace both the master cylinder and booster pump which would be 3000 dollars worth of parts and labor. After research this issue I have found serval people have the same issue. Also the parts are on back order, showing you how big of issue this is. The breaking system felt spongy, my traction control braking system and ABS lights came on. Thankfully I had just a couple of feet to my driveway.

Filed Dec 3, 2018 · Brakes · 100,000 miles · FL

The vehicle was traveling over 60 MPH when the ABS, brake and traction lights came on and the brake became immediately spongy and I had to depressed even harder (past the foaminess) to reduce speed. A motor could be heard trying to turn over on the brake system. The car speed was reduced to 25-30 MPH on the highway but the spongy brakes continued. Within 5 min I pulled off the highway and into a parking lot. Parked the car, turned it off and on to see if that would remedy the situation and nothing changed. I then called the toyota dealership's service department to book an immediate appointment and arrived at the dealership approximately 40 minutes later. The car was looked at and I was told that the brake actuator was the issue and that they would like to contact toyota to see if this was in warranty or part of the recall. I was told the next day that the cost of installation and parts would be at least $4,000 and that I would need to pay the full amount as toyota was taking no responsibility. I called the toyota customer service line, explained my situation and was told the same thing as I was told at the dealership. I feel that this brake actuator (its parts, its composition and/or its installation) is a systemic issue with toyota products and a known issue with toyota prius' in 2009 and 2010. Tangential to this issue, my father owns a toyota car as well and has also had to have his actuator replaced this year. Toyota should be held responsible for all faulty parts and installation and purchase of new parts. My maintenance record is exemplary and my driving record is as well so this is not regular wear and tear in my opinion.