2013 Toyota Prius

While driving suddenly the traction control light, the ABS light, the Brake light, and the Master warning light went on. I was able to pull off the road and stop by exerting an abnormal amount of pressure on my brakes. The vehicle was towed to the dealer where it showed code C1391. Toyota service bulletin T-SB-0024-19 addresses this saying it is caused by an internal brake fluid leak inside the brake booster assembly with master cylinder. Toyota is aware of the problem and has redesigned the parts. This is a dangerous problem with 2011-2015 Prius vehicles.

The car entered into safe mode suddenly while driving on the freeway and caused me to lose the brake booster with no audible alert. The brake light, ABS light and Traction Control light showed up on the dashboard. The regenerative brake got deactivated too. I was able to stop the car to a safe place by pressing hard on the brakes. This is very concerning as no warning was issued and didn’t expect to lose the break booster while driving at high speed on freeway. Toyota had issued a recall on this but only covering cars under 150,000 miles and mine has 189,000 miles. It is a 2013 Prius 3 model.

Symptom: Brake pedal felt spongy with multiple dash warning lights ON and booster pump cycling on/off. Safety Risk: yes, my Prius felt like it wasn’t stopping properly. My family and vehicles around were put at risk. Problem Confirmation: the problem has reproduced and has been confirmed by a local Toyota dealer. DTC: C1391 Warning lamps: there is multiple lamps On: Brake, ABS, trac/vsc, “!” There is a Toyota Customer Support Program(CSP) : Prius Brake Booster Pump and Brake Master Actuator CSP ZJB. I also reached out to Toyota and I was told the repair would not be covered due to mileage but was within the 10 year “use of date”. (10 year or 150,000 miles) My Toyota case number is: 230324001393

Brake accumulator may have a leak. Three brake warning lights came on while driving; the parking brake, traction control, and ABS. After the lights came on I noticed the brake accumulator coming on more often and needing to apply more pressure on brake pedal when stopping. I did some research and found that there was a recall for that same part on the 2010 Prius. I haven’t had the car looked at by a mechanic but I was able to see and confirm that it was the brake accumulator/ actuator. Vehicle only has 87k miles and has had regular maintainance.

On appx. 11/18/21 I was driving my vehicle on the commute home from work, appx. 15 miles, when 4 Brake Indication Lights displayed themselves showing that there was some level of issue, whether major or minor, with the braking system. 2 "Brake" warning lights were illuminated along with the ABS Light and the SLIP Indicator(traction control) Lights also. Not knowing the level of severity of the issue and the car "seeming" to sufficiently stop the motion of the car I proceeded to use the vehicle supposing it were a miniscule issue such as brake fluid level, brake pads, wheel sensor or etc. With the Toyota vehicle still having a lengthy life expectancy at that time I proceeded forward until more work was needed on the engine itself around late 2022. This also posed a situation for myself to look through papers and documents accumulated on the vehicle of which a paper was observed possibly linking to my current braking issues. On 2/4/23 I took the 2013 Prius by an authorized Toyota Dealer for diagnosis on this "Brake Light" matter as the lights were still turning on and off at random abnormal times. The brake booster component was confirmed failed in regards to the expired recall ZJB that Toyota initiated on certain Prius year models. At this point in 2023 no assistance was offered by Toyota to make this repair of my failing brake booster even though the car mileage currently sits around 218,000 miles. 10 years of use for this car have not even passed for this vehicle at the time of this writing and Toyota vehicles are regularly known for a life span beyond 150,000 miles that the secondary coverage window of the Brake recall offered. It seems that calculation method determined for the active recall concerning the braking system on this model/s Toyota Prius has been miscalculated and should be observed again to broaden the scope of assistance provided by Toyota given that most of the affected cars can be expected to have a life beyond the current recall window.

In April 2022, the brake booster pump activates every 20 seconds without applying brake. Brought the car to the dealer but service representative said since there is no trouble codes, Toyota will not cover brake booster pump replacement under Customer Support Program ZJB, and I'll have to pay for diagnostic fees. I took the car back without going through diagnostic test. Lately (Jan 2023, only 71800 miles driven), the booster pump would activate every 13 seconds, still not showing any trouble codes. Hissing sound can be heard inside the car and outside, especially on the driver side when parked, between each pumping cycle. Braking feel soft and insufficient towards the end of the 13-second cycle. It is a serious safety issue should the brake booster pump fail while driving. A recall should be issued instead of a customer support program, with limitations, which only address the issue only after trouble codes appear.

Traction Control Warning Light and ABS!! Warning Light and Brake Warning Light are remaining on in my dashboard when I am driving, then my Brake changes to hard to press that is abnormal. Mechanic told me my car’s error code relate with this issue is “C1391-Leakage in accumulator abnormal”, so it is related with “ABS Module” and “ABS Accumulator Pump”

I was parking my car inside the garage, when suddenly feel like it was skidding, and I thought it was going to hit the wall. Then I saw the ABS, brake skid control, and brakes lights. After that incident the car feels like loosing half of its breaking power, the regenerative breaking was not longer working. I could hear a noise related to the break pressure pump every 4 seconds when normally it was longer. I connected the computer to look for codes and found the C1391 "Break Accumulator leak". Having this abnormal frequent pump running will wear it more up to the point that it would not pump any more leading to a catastrophic failure with lack of braking. Investigating about this issue it looks not isolated with several people reporting the same issue, even there was a recall but just up to 2010 models, but the problem is more spread since I am also experiencing exactly the same issue.