2011 Toyota Prius — Known Issues & Recalls

While driving, your brake warning light, ABS light, and traction control light came on together, and you felt the car lurch unexpectedly. You're also hearing the oil pressure pump cycle on every 5 seconds. Toyota dealers have told you the brake master cylinder and booster pump are failing, which could result in complete brake failure while driving.

Your car's ABS, traction control, and brake warning lights are all on at the same time. According to Toyota technical documentation, this points to a problem with the brake booster and its pump — the system that makes your brakes easier to press. You've also lost regenerative braking (the Prius feature that recovers energy when you slow down), which means your brakes may feel less responsive and could put you at risk. The brake booster and pump assembly will likely need to be inspected and replaced.

Your brake master cylinder failed while driving, causing your brake pedal to go soft and requiring you to push it all the way to the floor to get any braking response. All warning lights appeared on your dashboard, and you experienced a dangerous loss of braking power that could have caused a serious accident. The dealer diagnosed a leak in the brake accumulator assembly and recommended replacing the brake booster, master cylinder assembly, and brake booster pump assembly.

Your brakes suddenly lost about 80% of their stopping power, and your ABS (anti-lock braking system) stopped working. Your dashboard lit up with brake, ABS, and traction control warning lights. The brake actuator — the component that helps distribute brake pressure — has failed, which matches a pattern seen in over 500 similar complaints. The fix will likely require replacement of the brake actuator assembly and a full brake system inspection.

Your Prius's ABS brake pump booster and actuator failed, leaving your brakes less responsive than normal. Although your brakes still work, the reduced sensitivity nearly caused an accident. This is a known issue that affects vehicle safety, and Toyota should cover the repair cost.

Your Prius's anti-lock brake system (ABS) actuator has failed, causing your brake pedal to feel abnormal and your brakes to perform inconsistently. A Toyota dealership has confirmed the ABS actuator assembly needs replacement. This is a serious safety concern because it can affect how reliably your brakes work and may increase your stopping distance, especially in sudden stops or on wet roads.

While driving at 55 mph on the highway during rush hour, your regular brakes suddenly stopped working completely, and your emergency brake also failed to function. Multiple warning lights related to the braking system came on (ABS, traction control, and brake lights), and you noticed a consistent hissing noise coming from under the hood. You were fortunate to be on an uphill slope that allowed you to slow down naturally, but you recognize this could have caused a serious accident under different circumstances. The issue likely involves the brake hydraulic system, vacuum line, or brake fluid contamination, and will require professional brake system diagnosis and repair.

Your ABS, brake, and traction control warning lights are turning on and off intermittently. You suspected a brake fluid leak, but your mechanic found no visible leaks after inspection. This issue appears to be common in Prius models according to online forums, and you're concerned about safety risks from a potential internal brake system defect. A thorough brake system diagnostic and possible ABS module replacement or brake fluid sensor repair may be needed.

Your car's ABS and brake warning lights stay on continuously. A mechanic diagnosed the problem as a faulty ABS brake booster and pump. Toyota has acknowledged this is a known issue but is refusing to replace the parts. Fixing this will require replacing the ABS brake booster and pump assembly.

Your ABS (anti-lock braking system) warning light is illuminated. The dealer has confirmed that your brake actuator and accumulator need to be replaced, which will cost over $3,000. This appears to be a known issue affecting Toyota Prius vehicles, but the dealer has declined to cover it under warranty.

Your ABS warning light appears and disappears intermittently on your dashboard, and you hear computer-related noises near the front driver's wheel when this happens. Additionally, your tire pressure warning light is now blinking continuously instead of its previous pattern. You're concerned about diagnostic costs and whether this could be a software issue or manufacturing defect affecting multiple 2011 Prius models. Fixing this will likely require a diagnostic scan of your ABS and tire pressure monitoring system, and possibly a software update or sensor replacement.

Your Prius has a brake booster and actuator assembly that failed at 129,000 miles. Toyota had a Customer Support Program covering this part for 10 years or 150,000 miles, but you didn't receive the notice because it was sent to the wrong address. Since your car is now outside the 10-year window (even though it's under 150,000 miles), Toyota has refused to cover the repair under warranty. Fixing this will likely involve replacing the brake booster and actuator assembly.

Your ABS, brake, and skid warning lights stay on while driving, and you hear a whirring noise from under the hood every few seconds. Your brakes require longer stopping distances than normal, and your brake pads and rotors wear out faster than expected. You may need diagnostic testing to identify the ABS system fault and potentially have the ABS module or brake system components replaced.

While driving on the highway at over 70 mph, your car displayed a "check hybrid system" alert and check engine light, then shut off completely within 2 minutes—leaving you stranded between two lanes of fast-moving traffic. The sudden failure with almost no warning created a dangerous situation. The repair required a new hybrid battery, but there were no prior warning signs that it was failing.

Your 2011 Prius was hit head-on by another vehicle in an intersection, but the airbags failed to deploy even though no warning lights appeared beforehand. You were pinned in the vehicle and suffered serious injuries including internal and external bruising, cuts, and a significant neck injury that may take weeks to months to heal and could potentially cause permanent stiffness and cramping. The vehicle was totaled in the crash. Diagnosing this issue would require a professional inspection of the airbag system components and crash sensors to determine why they didn't activate during the collision.

Your Prius's aftermarket lithium battery pack threw an error and put the car into limp mode while being driven. When you checked the battery with a scanner, you found that the individual cells were out of balance and some were overcharging. Your concern is that continued overcharging could cause a thermal runaway event (dangerous overheating) because the battery management system wasn't properly integrated with the aftermarket pack.

Your check engine light stayed on, your car shut off unexpectedly while driving, and the transmission wouldn't shift into the gear you selected. The dealer replaced the catalytic converter, but the problem continued. They then found the inverter (which manages power in your hybrid system) was faulty and needed replacement, but the repair wasn't completed. You believe your car matches a known recall issue, but your VIN wasn't included in the recall campaign.

Your brake warning light, ABS light, and master warning light came on while driving. A mechanic diagnosed problems with your brake master cylinder and hydraulic accumulator, which are critical parts of your braking system. These components may need to be replaced to restore proper brake function.

You discovered that the odometer reading was significantly lower at purchase (145,000 miles) than at registration (227,000 miles), indicating the mileage may have been tampered with by the dealer. Shortly after purchase, your check engine light came on while driving at highway speeds, and a diagnostic check revealed your catalytic converter has failed and needs replacement—a problem that may have existed before the sale, with the warning light possibly cleared beforehand.

Your traction control and ABS brake warning lights came on, and you noticed your brakes became harder to press, though they still work. Your mechanic says the ABS hydraulic system is triggering fault codes and estimates the repair at $3,000. The problem started last month and you're concerned about your safety. The fix will likely require diagnosing and repairing the ABS hydraulic system components.