NHTSA Complaint #11651221 — 2012 TOYOTA PRIUS

Subject: Safety Complaint – 2012 Toyota Prius Brake Booster Failure (C1391 Code) I am writing to formally report a serious safety defect in my 2012 Toyota Prius involving the brake system. Recently, my vehicle’s dashboard displayed the ABS, traction control, and brake warning lights, indicating a critical braking issue. Upon diagnostic testing at a Toyota dealership, the vehicle was found to have DTC Code C1391 – Brake Booster Leak/Accumulator Failure. I later discovered that Toyota acknowledged this defect and issued a Customer Support Program (CSP) to cover repairs. However, I was never notified, despite always servicing my vehicle at Toyota dealerships. When I contacted Toyota, they confirmed that my vehicle has been flagged in their system, yet I was never received anything in the mail about the potential brake failure. Toyota initially set the CSP expiration in 2023, later extending it to May 2025, but they have refused to repair my vehicle under this program. The estimated repair cost is $4,680.09 along with a diagnostic fee of 206.09, which is a significant financial burden for an issue stemming from a known manufacturing defect. Most importantly, this is a major safety hazard: My brakes now produce a loud hissing sound when pressed, indicating imminent failure. If the brake booster fails completely, it could result in a loss of braking power, endangering myself, passengers, and others on the road. Numerous Prius owners have reported similar failures, yet Toyota has not issued a formal recall. I urge NHTSA to investigate this defect further and push Toyota to issue a full recall instead of a limited support program that many owners were unaware of. Given the life-threatening nature of brake failure, Toyota should not be allowed to limit coverage or deny repairs for a problem they have long recognized. I respectfully request that NHTSA take action to ensure Toyota addresses this safety defect responsibly.