Gen 2 Traction Control issue

Yes generally it's called normal activity of the traction control anytime your tires do not have enough traction The traction control will try to detect it The light will flash on the dash All of your tires are the same size etc this is important other than that going over train tracks and slippery things like steel plates in the road extremely wet road where you can see the rainbow showing off of the hue of the road because of the oil things like that those are slippery things when you hit those at any kind of speeds I don't care if it's city speeds or half highway speeds or past the speeds that Jeepers creepers drove at doesn't matter if the car detects it that's what's going to happen It doesn't speed up I don't think you're feeling the right feeling but we won't argue that what happens is is it's trying to do a bunch of things at one time to the wheels that aren't making good traction which is going over train tracks is all four of them for a second like two at a time depending upon how you're hitting the tracks If you really want to see what the car is doing with the traction control put a 195 60 15 tire on one of the wheels and put it on the car and you'll see the light come on all the time every time you accelerate and try to move up and down through speeds it'll keep you from getting 55 miles an hour and when you do it feels really funny etc etc now if you think something's really wrong you could just run the codes on the car and see if there's any data on the wheel speed sensors that don't look up to par what does that look like I have no idea I'm sure there are data points online where people will talk about using the Toyota software and looking at the data points of the wheel sensors and the numbers that you're looking for I don't know what they are what I do know is I don't want my traction control light clicking on and off unless there's something really going on on the road which in your case there is train tracks and they're slippery We ever tried going over them not sideways but at an angle you know what I mean like a slip angle where one tire gets over first then the other then the back do the same thing try it and see what happens sometimes driving style can make all the difference if you want to work on the car just work on the car but I think everything's pretty normal does it do this at other times like when you hit slick spots in the road right after it's rained just a little bit to make it obnoxious on the surface of the road we drive our cars all four of them they don't drive us I've had them sliding down the road before traction control and squiggly lime lights and all that flashing like crazy car going berserk Life lit up like Christmas trees oh well not much is happening You certainly can't go very fast doing that I think that's the point.

 

Regardless of how you decipher that, the car is not accelerating. The traction control is doing it's job, and very rapidly adjusting each tire to ensure the car stability is maintained when one or more wheel slips. The acceleration you believe you're feeling is more likely deceleration being applied and released. It's a relatively common sensation that gets posted about.

 

When I bought my first Prius in 2008, I came to PriusChat and started reading, and I saw some posts about that effect before I had ever experienced it myself. Looking for more detail, I posted this thread:

What is the bump-during-braking oddity I keep reading about? | PriusChat

The explanation qbee42 gave me then is still good.

The nice thing about having posted that thread and had that conversation early, before I had ever experienced it in the car, was that I could then go out on purpose and find a place I can drive and make it happen (there's one right on the street out of my neighborhood where I can make it happen every time) and learn how it feels and get used to it. Just as qbee42 said, it should be no cause for alarm, and you don't have to react in any fancy way besides keeping your pressure on the brake according to the slowing you want.

We should maybe do a better job making sure new owners still see that information early when they discover PriusChat. It's a familiar behavior of the cars that people ought to know about so their first experience of it doesn't alarm them.

 

No I'm not saying that at all It should not automatically accelerate the car so you need to figure out what's going on and you have no codes and the capable code reader All righty I'm not sure that's what you're feeling but maybe you know I can't feel it from here but I don't know about accelerating the car and usually does anything but when attraction control is going on and activated usually you play almighty trying to reach 55 miles an hour and what have you and the traction controls constantly fluttering in and out in and out this is when you have a mismatched tire I've had this happen a bunch of times Just playing around with the car to see why I can't put this size up front and this size on back apparently you can't do that when these type of systems are engaged in the cars design or then maybe something you have to do when I tried it it would engage the traction control consistently and constantly when I go over oily surfaces like at the beach in the morning right after it's rained and I'm driving like I'm not supposed to I can see and feel the traction control activate and see the light on the dash and I can assure you the car is not accelerating it might be slipping but no it should not so if that's what's really happening in your car you may need to figure out why never seen that before I've got four or five of these things and two generation 3s that sit never experienced car accelerating with traction control that's usually the opposite of what will happen

 

I'd suggest using Techstream (or some comparably full-featured scan tool) to pull up the "ABS History" from the car after this has happened. (It's called "ABS" history but includes the most recent four times either the ABS or traction control activated). It shows everything the car thought was going on at the time (overall speed, wheel speeds, g forces, yaw rate, and so on). You could post that information here. Maybe also collect a datalog of the speed and acceleration rate from before, through, and after the event.

Edit: well, I was thinking of a gen 3. I'm not positive your gen 2 has an "ABS History" to pull up. (Maybe it does, I just don't know.) If it doesn't, then just datalogging the related live data while you drive over that patch might be the best approach.

 

Kind of like when ABS first came out everybody had all these funny things going on and then they all just disappeared the funny things and now it's the way brakes work

 

can you replicate it with someone videoing the speedometer?

 

Ding...Ding....Ding
Here comes Round 53!!