A Consumer Reports:
As driver of a 2010 Toyota Prius I find it my duty as a concerned consumer to report a dangerous feature. Applying the brakes while the vehicle is traveling over a pothole, bump or bumpy and slippery road can cause an accelerating sensation and temporary loss of control of the vehicle. I say "accelerating sensation" because that's what it feels like, when in actuality the brakes are failing.
When I first reported this to the Toyota dealership they had me ride with one of their mechanics to demonstrate/duplicate the problem. The mechanic driving was unable and/or unwilling to verify the problem. Granted, we both had a hard time duplicating the braking issue since the roads near the dealership were newly blacktopped and in mint condition.
With me driving we drove to an older blacktopped area and while braking on a hill I noticed the accelerating sensation, not as abrupt as usual, before the brakes kicked in. I immediately informed the mechanic and he said he didn't notice a thing. My girlfriend has also experienced the acceleration sensation when driving over bumps, but never has a passenger noticed it.
The mechanic did explain about a Toyota recall where the brakes were releasing over bumps and causing the sensation of acceleration, but he said the recall didn't apply to my vehicle because it already had the software upgrade. It was the first time I'd heard of this Toyota problem and the first time anyone at Toyota mentioned a brake recall and/or software upgrade for braking.
When the mechanic and I got back to the dealership I asked the service advisor about the recall and he confirmed there'd been a brake recall, but repeated the mechanic's words verbatim that the recall didn't apply to my vehicle because it already had a software upgrade.
I left the dealership feeling like Toyota was covering up for a brake defect in my vehicle. I couldn't fully blame the mechanic for not noticing the mild acceleration I noticed while driving with him in the passenger seat. I did find it very odd that both Toyota employees knew about the brake recall and the software upgrade to address it, yet neither mentioned it to me until after we'd test driven the vehicle. When I voiced my concern of their reluctance to divulge such critical performance information about Toyota's brake recall the service advisor apologized, then gave his reason as not wanting to mislead or misinform customers prior to testing the vehicle.
Forward 2-3 years as I bring my same Toyota Prius in to the same Toyota dealership location for a scheduled performance service. I bring up my concerns about the continued braking issue and fill in the service advisor about the prior visit where the Toyota mechanic's test drive result was inconclusive. The service advisor agreed to have the mechanic take a look at the braking system.
After servicing the vehicle the mechanic and service advisor met with me and explained the brakes were fine. I told him how I understood it wasn't the vehicle accelerating but the brakes releasing when I apply the brake peddle while going over a bump(s). The mechanic stated that's exactly how the brakes are designed to perform. He said that anti-lock brakes, such as the ones installed in my Toyota Prius, are designed to temporarily release when the vehicle goes over bumps.
When I told them of the danger and helplessness a driver experiences during that "temporary" loss of vehicle stoppage the mechanic said I shouldn't drive so close to other vehicles and began admonishing all drivers who tailgate. I turned to the service advisor with a look of "is he serious?" on my face. The advisor was as still, pale and silent as a porcelain statue. I turned back to the mechanic saying adamantly that I do not tailgate and that safety while driving is part of my job training and responsibility.
Then I asked him point blank if I could get him in front of a judge, any judge, to say exactly what he'd just so boldly stated. You could hear a pin drop. Finally, I could do nothing but laugh and pat the mechanic on the back. This poor heavily accented guy was obviously foreign born and was just doing his job and probably towing the company line. The slick service advisor, with the touch of a used car salesman, eased the conversation toward other service checklist completions made by the mechanic and nothing more was mentioned about Toyota's braking system.
Since that last, most recent Toyota maintenance service experience I've found alarming online information about the Toyota Braking Issue on my 2010 Prius models. Wouldn't hurt for consumers to get an understanding about Toyota's regenerative braking systems as well.
Once I got home and completely looked over the Toyota customer service receipt showing all the maintenance performed during the visit, I noticed a page describing the replacement of Curtain Shield Airbag Brackets. Under the heading for CAUSE, was the description: Open Safety Recall.
I called back the service advisor and after what felt like pulling teeth, with him dodging and dancing around the reason for bracket replacement, he admitted that replacing the brackets were due to a recall. I figure maybe he's a summertime auto salesman coming in from the cold of winter to work the service desk. Why else would a Toyota service advisor not advise a customer about product safety recall maintenance just performed on his/her vehicle?
And if all that wasn't interesting enough, what triggered taking my 2010 Prius in for servicing in the first place was finding the oil dipstick almost completely dry. The Toyota mechanic confirmed finding no oil on the dipstick. The mechanic advised keeping an eye on the oil level moving forward for the next few months, nothing more. After the service visit I went online and found a class action lawsuit against Toyota for guess what? an excessive oil consumption defect! Don't believe me, check this lawsuit verbiage:
This action arises from Defendants’ failure, despite their longstanding knowledge of a material design defect, to disclose to Plaintiffs and other consumers that the Class Vehicles are predisposed to an excessively high rate of engine oil consumption (the “Oil Consumption Defect”). This defect – which typically manifests itself during and shortly after the limited warranty period has expired will inevitably cause the Class Vehicles to prematurely burn off and/or consume abnormal and excessive amounts of engine oil.
The existence of the Oil Consumption Defect poses a safety risk to the operator and passengers of the vehicle because it prevents the engine from maintaining the proper level of engine oil, and causes an excessive amount of engine oil consumption that can neither be reasonably anticipated nor predicted. Further, the Oil Consumption Defect can cause engine failure while the Class Vehicles are in operation at any time and under any driving condition or speed. This exposes the driver and occupants of the Class Vehicles, as well as others who share the road with them, to an increased risk of accident, injury, or death. As discussed further herein, numerous owners and lessees of the Class Vehicles have experienced engine damage and catastrophic failure while operating the Class Vehicle, thus placing themselves and those around them in immediate danger.
As alleged, Toyota has long been aware of the Oil Consumption Defect yet has routinely refused to repair the Class Vehicles without charge when the defect manifests.
Toyota Recalls Prius models to update software
Toyota Engine Excessive Oil Consumption
OIL CONSUMPTION DEFECT - Class Action Lawsuit Against Toyota
Excessive Oil Consumption Customer Complaints