2012 Toyota Prius service brakes problems

“I own a 2012 Toyota Prius with approximately 132,000 miles. I first experienced problems with the braking system approximately one year ago, in 2025. The ABS, brake, and other warning lights began illuminating intermittently, and I experienced occasional hesitation in braking response. I was concerned enough about the vehicle's safety that I stopped driving it for an extended period. After recently returning the vehicle to service, the warning lights continued to appear intermittently, even when the brakes seemed to function normally. An independent mechanic inspected the vehicle but could not retrieve a diagnostic code at that time. On November 1, 2026, an ABS diagnostic scan at O'Reilly Auto Parts confirmed trouble code C1391, "Abnormal Leak of Accumulator Pressure." The diagnostic report recommended replacement of the brake booster and master cylinder. Toyota previously acknowledged this brake booster problem through Customer Support Program ZJB, which covered certain 2010–2015 Prius vehicles with this defect. Despite my vehicle having fewer than 150,000 miles, Toyota informed me that the coverage period had expired and that no exceptions would be granted. I…”

“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.”

“1. My Brake booster failed/malfunctioned. I had to get it repaired/replaced by Toyota so it might be with the dealership or thrown out by now. 2. I had to take it in because I had an incident where I was unable to apply the break on the car. I was lucky enough to be in a not busy street and was able to pull over safely. 3. Toyota diagnosed the issue and proceeded with the repair. They even have an extended warrantee but due to covid I was unable to get the repair in time for it to be covered by one year and had to pay. 4.Toyota did inspect and diagnose the problem. I have already paid for the repair with the dealership. 5.I had some breaking issues but I had brought it to an independent mechanic and they said it was my rotators since they needed to be replaced soon. I replaced them but then still had the issue and that's when my breaks stopped working for a brief time and I took it into Toyota to get it fixed. It been a while at this point but I do remember there being warning lights that turned on because of this issue as well.”

“My 2012 Toyota Prius is experiencing brake actuator pump failure, presenting diagnostic trouble codes C1253 (brake actuator pump motor stuck/locked) and C1256 (brake actuator pump motor overcurrent). These codes trigger ABS, brake, and VSC warning lights and disable ABS and stability control. Toyota previously acknowledged this exact defect under Customer Support Program ZJB, which covered 2010-2015 Prius vehicles for brake booster and brake booster pump assembly failures triggered by these specific codes. I am the original owner of this vehicle, purchased new in 2012. I never received notification of CSP ZJB despite being the registered owner at the time notifications were distributed in 2019-2021. My current mileage is under 150,000 miles, within the secondary coverage mileage limit established by the program. Toyota has declined to provide goodwill coverage citing program expiration. This is a known safety defect that reduces braking effectiveness and disables ABS — it should have been addressed through a mandatory recall rather than a voluntary program with an expiration date that left original owners without recourse due to failed notification.”

“Almost had an accident due to the brake master, actuator and booster pump assemblies, failing. There were no warning lights alerting me to an issue. Just lost ability to break and car shut off completely while in motion.”

“The brake booster and brake booster pump assembly (also referred to as the Accumulater or Accentuater) have failed in my vehicle the same as Toyota's known defect that was mentioned in their Customer Support Program 20TE07 (part numbers can be found within the filing of their CSP 20TE07). I am reporting that this issue appears to have affected more than their initial estimate of ~118,960 states impacted vehicles.l because Toyota is declaring my vehicle is outside of their CSP 20TE07 although their defect endangers my safety (and the safety of others) and attempts to put their defective vehicle brake parts as my financial burden. This issue should have been/should be a larger recall. Thank you.”