2012 Toyota Prius C: ABS light or ABS activating

Filed Jan 21, 2026 · Brakes, Driver assistance · TX

While driving 65 mph on the expressway on January 12th, 2026 under cruise control, I tapped my brakes to slow down. My brake warning light came on, along with the ABS warning light, and the anti-swerve warning light. Cruise control no longer worked, and my brakes were noticeably hard to apply. I immediately had the vehicle computer checked and the issue is a leaking brake booster component, a faulty part known by Toyota to fail prematurely with this and other Prius models. No recall was issued however. The car is now unsafe to drive until a ~$4000 repair is done, according to my service representative.

Filed Aug 18, 2025 · Brakes · CA

I own a 2012 Toyota Prius C with approximately 156,578 miles. The vehicle has been diagnosed with C1391 – Abnormal Leak in Accumulator, which causes the brake actuator to lose hydraulic pressure. This results in frequent buzzing from the actuator pump, illuminated warning lights (BRAKE, ABS, Traction Control), and loss of ABS and stability control. The condition increases stopping distance and creates a serious safety hazard. Toyota previously acknowledged this exact defect under Customer Support Program CSP 21TE01, which covered brake booster and pump assemblies for certain Prius and Prius C models when codes such as C1391 were present. However, the program expired on November 30, 2022, and my vehicle is just over the 150,000-mile coverage limit. Despite this, my Prius exhibits the same defect that Toyota has already recognized as a safety-related issue. Toyota Carlsbad confirmed the diagnosis and quoted $3,399.55 plus tax for repair, with a reduced courtesy estimate of $2,817.86 plus tax, but declined goodwill assistance since CSP 21TE01 expired. Given the widespread reports of brake actuator failures in Prius models, I believe this represents a systemic safety issue that warrants the federal safety agency investigation and potential recall/extended coverage.

Filed Jul 15, 2025 · Brakes · TX

Brake Actuator and ABS Accumalator failed. It is a common failure reported by multiple owners on these cars. I was on the high way going 70 when it failed and lost any brake boost I had putting me in a very dangerous situation where I narrowly avoided an accident. Upon scanning the car's codes I got code C1391 which I looked up and saw a bunch of other people who were also struggling with this issue.

Filed Jun 2, 2025 · Brakes, Electrical · PR

I am writing to express a complaint regarding the issues I have experienced with the brake system of my Toyota Prius C, 2012 model. For the past several months, I have noticed that the brakes exhibit strange noises, soft pedal sensation, reduced braking efficiency, were driving and the ABS, traction, brake, and that other light turned on and the brakes became slow these issues have been observed on multiple occasions and pose a safety risk to myself, other drivers, and pedestrians. I have taken the vehicle for inspection, but the problems persist or have not been definitively resolved. I believe these faults may be related to defects in the braking system, and therefore I request a thorough inspection and necessary repairs at no cost, considering that the manufacturer could be responsible for manufacturing defects.

Filed Jan 26, 2025 · Brakes · FL

My ABS actuator failed. Turns off the boosted braking and cruise control. This is a known issue in Toyotas and it always happens outside the warranty window. This is putting my safety at risk as the brakes don’t work as they’re supposed to

Filed Jun 30, 2024 · Brakes, Electrical · NY

While my daughter was driving brake pedal faded and rear brakes locked up causing her to lose initial control of car . Steering felt tight . Many warning lights , check hybrid system , brake lights , steering warning lights , along with abs lights came on . Took car to Toyota dealer to diagnose it needs brake booster and master cylinder module . Service consultant said known issue with TSB but it had expired . Many , many complaints of this same incident of Toyota and Prius forums .

Filed Oct 11, 2023 · Brakes · NC

The brakes fail and the ABS module stops working correctly and when I go at a speed of 60 MPH the brakes lock until the speed drops and they work again. The problem is with the ABS module and I went to the dealer and the repair value is $3450 dollars.

Filed Jun 9, 2023 · Brakes · CA

Last week my 2012 Toyota Prius-C had four lights come on (ABS, Brake, Swerve, and one other). I took it to my local mechanic who informed me that it was my master cylinder brake that needed to be replaced and would cost me $3,300. This issue started roughly 10-12 months ago, when I heard my brakes making a noise that sounded very unusual, almost like a hydraulic issue. I learned that there was a Toyota initiated CSP. Toyota realized there was an issue with the 2012-2014 brake system that affected over 100,000 vehicles. Those affected by CSP's are supposedly notified by mail. Needless to say, I never received such notice. This aforementioned CSP expired in November 2022 that my car would have qualified for, had the problem been diagnosed prior. However, when I brought my car in on August 8th, 2022 for my hybrid battery, a diagnostic was done on my brake system with no indication that my brake system was in trouble. I really can't fault the mechanics at the local Toyota, I took it to a second brake specialist a few months after and they too could not identify the problem. The problem was so bad, Toyota discontinued the brake system. Toyota said it would need to be broken 100% with an error message to qualify prior to the November 2022 deadline. After being facetious and saying I should have broken the part myself to qualify, she said that is what I would have needed to qualify.

Filed Oct 22, 2021 · Electrical · NM

I was driving going 45mph when my car shut off and wouldn't start back up. It almost caused an accident from it stopping in the middle of the highway. The master warning light, brake system warning light, warning buzzer ABS warning light and the slip indicator light came on as also the message center reading to have the hybrid system checked immediately. I did have ot towed on for a diagnosis and it came back saying i needed a new inverter power module this will cost $2000 . i cant afford that. I read all over the internet how there is. Safety recalls. When i called toyota they said there are no recalls so now im stuck paying this. Not happy at all!!! If there are anymore 2012 prius with this problem please write a complaint so we can get this on recall and have the company cover the cost of repair.

Filed Jan 19, 2016 · Brakes, Driver assistance · 87,000 miles · PR

Brake booster w/ master ECM communication malfunction -unable to communicate and performs ABS, anti slippery and brake pedal to low. The malfunction includes warning lights panel to stay on.

Filed May 28, 2013 · Airbags, Body · 5,000 miles · CA · crash · 2 injuries

The brakes were applied gently as the car was approaching a stopped car. The prius c then accelerated, at which time the brakes were firmly applied, the ABS system engaged, but not in enough time for the vehicle to stop. The prius rear ended the vehicle in front, all airbags were deployed causing injury to the driver, and the front end of the prius was destroyed. It cannot be fixed and will need to be scrapped.