I purchased my 2010 Prius II yesterday. The dealership assured me they put in the software fix before handing me the key fob. Car drove well coming back from Long Island to Brooklyn on highways and local roads. This afternoon, I helped my wife load a couple things into the back of the car and watched her drive off. As she pulled away, I could see the right rear tire lock and leave a yellow trail behind the car. The other three tires (from what I could tell, running behind her yelling for her to pull over) were moving fine. As she slowed down, I could see something slide out from underneath the rear right tire and for the last five feet of slowing the tire rolled and decelerated fine. I ran first to the window to see if she was ok and if she noticed anything while driving. She said it felt like something was dragging. I had her drive forward for another 20 feet and the rear right wheel rolled fine and slowed fine when braking. I walked back to the yellow trail and saw that the "something" that slid out from underneath the tire was a piece of particle board (about one inch thick). So I am guessing that the particle board wedged under the tire and somehow activated the ABS for that wheel but failed in some way to "pump" the brake and disengage the particle board. This does not sound like the correct way ABS should perform. Does anyone with deeper knowledge of how ABS is implemented on the Prius provide some insight? In the meantime, I left a message with the service center at the dealership (closed today).
I don't think has anything to do with your abs or your brake fix. You dragged a piece of something. Doubtful the dealer will be able to do anything since there doesn't seem like there is anything which needs fixing.
Totally understand the sensitivities. I just tried editing the title and didn't work. I'll try contacting an administrator to get this deleted so I can post under a less inflammatory thread title. Sorry about that.
+1. If the wheel is rolling when the brakes are not applied, and stopping when the brakes are applied and there is no other symptom (like pulling to one side or another), there likely is nothing wrong with the car. Look at the bright side - your car has the brake fix applied/installed. But if a trip to the dealer for the service dept. to check things out will address your concerns, by all means, make the trip.
+2. Getting something stuck in the wheel has nothing to do with the brake fix. "Possible Problem with the New Brake Fix" is the revised thread title? If so, it's still misleading.
+3 Nothing in ABS or any other system will dislodge an object that stops tire rotation. ABS keeps the brakes from locking in order to maintain some traction.
ABS only activates when the brakes are engaged, and if you were to observe the wheel as it brakes with ABS pulsations I doubt you'd be able to see the effect (it would appear probably still to you as the pulses are extremely fast I believe). In any case, this is a clear mis-understanding of how Anti-Lock _Braking_ System works. In real practice, I believe you will still get occasional slip of the wheel especially if the vehicle is traveling fast - take a look at the skid marks on the highways, you'll often see a series of "dashes" representing the extremely short (but finite) duration when the wheel is locked during ABS engagement and emergency braking.
Not entirely true... our Kia van uses the brakes as part of the Traction Control System and is very obvious when it does (the noise and jerking). I assume the Prius does as well but it not as noticeable.
Perhaps differences in terminology, then, but I would call that the Traction Control System (TCS) and not the Anti-lock Braking System (ABS).
