Prius Traction Control Complaints on the Rise

You sure it wasn't a result of driving a car with brand new tires?

 

No. My 04 Prius with the brand new Integrity tires was absolutely helpless on snow and especially ice

 

The dry packed snow is not a big problem. That's what we had all winter in northern MN (can't afford to put salt on all those rural roads after each snowfall), and I much preferred that to the slushy or icy stuff I would see in Virginia and CT when I lived there. It's more like packed gravel than sand.

I can get the TC light to flicker in the current Chicagoland conditions, but it hasn't been too bad (generally it's because I'm trying to make it slip a little). I'm running stock OEM Integras on an '06 (pkg 1), they've got nearly 30K on them now. Only had one problem, and that was on an uphill incline after coming to a complete stop for a light, and the lane had been blocked previously by police because of icy conditions. I guess the police left to respond to some event but the lane was still icy. It took me about half a minute to work my way off the icy patch, and then I could accelerate like normal. Definitely nerve-wracking at the time. I give plenty of time when pulling out into any kind of snowy intersection, other drivers have been pretty understanding.

 

Well I'm up for a weekend of snow up in Lake Tahoe... while I have driven up there in "snow time" before, the roads before were perfectly clear, no chains, nothing, hopefully all goes as planned, I do have chains just in case, but this old thread just reminded me I should be a bit cautious.

 

Hi Nerfer,

I should have left out the word "packed". Allot of the conditions in DuPage county, off the well travelled/ well plowed roads was much like a sandy beach this week. It was common to have a mix of sand, salt and loose snow in the turns. At these temps salt does nothing but crystalize. Even some packed snow will turn into a flowing fluid with pressure on it, however. This is what I was thinking about actually when I typed that first message. With the mix of stuff, the snow does not remelt and bond. It just flows.

Friday was good driving conditions, however, if a bit cold. -15 F on my fully grill blocked temp sensor. When I got to work, the Ohare temp was -18 F. I abandoned the pulse and glide route, and took the interstate. This kept the engine temp above 70 C when traffic was moving, but I had shut off the climate control in the slow and go portions of the trip. Otherwise the car would have been below 70 C, and there would have been no gliding. They really need to extend the lower end of the climate control temperature setting. When your dressed for -20 F, a 65 F car temp is much too warm, and soaks up too much engine heat. And not running the climate control results in foggy windows. So, one ends up using it manually, rather than the original design goal of it being automatic. As this is one of the few temperature extremes I actually use the climate control, I hardly ever use it automatically. Its not within my practicality to do so. Making the automation failed in practical conditions.

 

I'm glad I wasn't the only one that experiences the same problem. Last winter was the deciding factor on trading in the prius partially due to what you just entailed with the climate control and fogging windows. The main reason I got rid of it was the lousy traction control. It did make for dangerous conditions for me. Pulling out of county line to route 20 in the morning if traffic is coming, and usually is, requires a jump on the throttle to pull out and get up to speed, otherwise it could be 10 minutes or more waiting for a large enough break in traffic. The road at that intersection usually has sand or gravel from the shoulders scattered about, so traction is always poor no matter what time of year. Pulling our is a left turn, and the TC ALWAYS kicked in, ALWAYS. It wouldn't matter what tires were on the car, they would spin. All my cars will spin there. One time I had to drive it when it was snowing, and it took me 5 minutes or more to go 100' up a slight grade, that was the last time I drove the car if snow was forecast. Now that I have the TCH, I could care less about snow, it handles it great, no TC issues, or anything. My wife spun it this morning though to avoid getting hit by a semi, but it handled it well, she's OK, the car is OK, and no one got hurt, I'm just glad she wasn't driving the prius, I don't know how the car would have fared in that.

 

Has anyone contacted Toyota about this problem? What do they say? Is this problem going to be fixed with G3? I can't imagine Toyota's people not getting together and fixing this.

 

Toyota knows about the issue. Traction control was greatly improved between 2004 and 2006. We expect that the Gen III will be even better, on par with the TCH or better, but none of us have had a chance to test it.

Tom

 

Thanks Tom! I live in an area where we get more ice than snow. I like the feeling of control in bad weather. I hope your right.
fred

 

I am happy that many people has not experienced the "stopping" of the wheels when the traction control so decides. It is a VERY unsettling event. I have a Touring model with the 16" tires, less than 20K on them. I have felt a twing of panic each wet morning for the last 2 year when I have to enter a 2 lane road from a stop sign leaving my neighborhood. In snow, even with decent tires, I fear a similar experience.

I have driven Toyotas for the past 25 years (Tercel, Corolla, Lexus sedan, Lexus SUV) and have never experience anxiety driving them on rain or snow, eventhough only the SUV had AWD.

What is this issue with the upgrade of the ECU? To my knowledge, my Touring '08 has the original factory software. Should I go to the dealer seeking an update?

 

You Prius has the updated ECU. If you drive in snow, you might need better tires.

Tom

 

NORMALLY you can't drive up Lombard Street. When you rent it for a photo shoot, though... ;-)

Bay Area Club DSM Home Page - it started raining while we were setting up, and some of the FWD guys couldn't handle backing up the street when one of the tenants had an "emergency" (they had to get to the laundromat! - violated our contract, we could have raised hell, but decided to be nice) and had to leave, we had to back up about 10-15 cars to let them out the top. One guy was so bad at it, one of the more experienced driver's hopped in his car, pulled into a driveway, turned around, and drove UP Lombard.

http://www.vfaq.com/BADSM/Lombard/Lombard-02.jpg - this pic was just for the fun of it before we began setup ;-) OK, actually, he was headed up there to get the setup started, it was easier to drive up (AWD) and corral people than try to get it done via radio.

 

I would strongly recommend that you invest in a set of Nokian WR-G2 tyres. After changing out the very poor OEM tyres, my 09 Touring now has good performance in bad weather (snow and ice). Before, I would rate the performance as poor. Tyres can and do make a HUGE difference.

 

I came from driving a Ford Five Hundred with AWD, which is a night and day difference in the snow, and as such I had to adjust my driving accordingly-I have to be much more defensive and aware in my driving of the Prius because of its more aggressive traction control and lack of size and AWD vs the Five Hundred.

If you have the stock Turanzas, they are horrible in snow/ice. Get the Nokian WRG2s.

 

The overactive traction control system places even a reasonable owner in danger because it does not behave like that in any other car most drivers will have experienced, It is MUCH more sensitive. The good news is that, for snow at least, a REALLY GOOD QUALITY ACTUAL SNOW TIRE (not an all-season tire) will significantly reduce the problem. I run Nokian hakkapeliitta snow tires and the improvement is worth the expense. If you live in snow country I strongly recommend snow tires. The Nokians are so good that I am considering leaving them on all year despite their limitations on dry pavement--they also help in the rain. And no, I do not work for Nokian... PS: I reported the traction issue as a safety concern to the fed govt, fyi.

 

The traction issue for a FWD hybrid driving on a slippery surface is an especially hard nut for the design engineers to crack. So TC, Traction Control, will be especially sensitive, maybe even lowering or even disabling regen capability in cold(er) climates.

You already know the ABS additional sensitivity, disable regen INSTANTLY (regen = front braking ONLY!) with initial ABS wheelslip/skid detection.

Now that almost all passenger vehicles have the capability I would think we would soon see a new braking design/technique wherein ONLY the rear brakes are used for light braking or until ABS detects rear wheelslip/skid.

IMO that technique would be much safer for wintertime adverse, slippery, roadbed conditions.

 

The new Infinity hybrid is to be RWD so these Toyota HSD traction sensitivity issues will likely not be present.

 

I have a 2005 prius, manufactured in 10/04.

When purchased, it had the OEM integrity tires on. I agree with everyone, they suck. The traction control light came on all the time.

With my new tires, Hankook 727's, I feel much safer.

However, will this continue into the winter? Should I check to see if my ECU is upgraded/how much will that cost/will it even fix the issue. It seems as though this "fix" is controversial?

My "winter driving" this year will be light(meaning not frequent, but when it occurs its usually decently bad), so it is not a huge concern, but again, I do not want to risk my safety.

 

You need to keep in mind that highly sensitive, AGGRESSIVE, TC, is very desireable on a FWD or F/awd vehicle as a safety measure. Given the level of TORQUE the HSD system can apply to those front DRIVE tires I would not be at all surprised if the Prius' TC is tuned to be even more aggressive in activation vs a non-hybrid FWD.

And remember that with front drive wheelslip/spin you have also lost ALL directional control of the vehicle.

 

No - an overly aggressive TC leads to unintended no-acceleration under slippery road conditions when permitting some limited amount of wheel spin would result in better acceleration and no loss of vehicle control.

Sample scenario:

Damp roads and you need to quickly change lanes and accelerate into traffic. One wheel hits a bot-dot and loses traction and the overly aggressive TC completely cuts power resulting in no acceleration for a half a second.

While TC has kept the vehicle under control, it has also abruptly changed vehicle behavior from what the driver is expecting.

A more reasonable response would note that only one wheel is slipping and apply brakes to the slipping wheel while cutting power moderately. Based on the results of this action the system could then determine whether or not to cut power more or release the brakes and allow desired power levels to resume.

Toyota skimped out on engineering in designing the Prius TC. It's a lot easier to simply pull-the-plug when wheel slip is detected rather than to moderate the response according to the amount of wheel slip.