Prius Traction Control Complaints on the Rise

There's no surface which is completely frictionless. The whole point of traction control is to utilize available (however small) friction as well as possible to move the vehicle forward in a controlled fashion. Your zero friction argument is nothing but a strawman.

It looks like the Prius HSD requires a higher friction threshold than traditional transmission based vehicles in order for its TCS to work correctly.

 

Straman or not, our friend Jayman reports plenty of SUVs with All-Season Tires turtled, or otherwise off the road in a ditch up there in Alberta.

I am not sure how your are making the conclusion in the second paragraph.

Yes, some people have operational difficulty with the Prius on slick surfaces. But, such difficulty can come from many sources. And what you suggest requires a change in the rules of physics. The smaller tires on the Prius, are usually what is favored on cars driven in snow, as the higher pressure, compacts the snow, causing it to sinter, and provide some sheer strength down to the pavement. If a wheel slips, even infitesimally, its optimum not to increase the torque demand on that wheel. The Prius does just this.

The traction control works well enough, if one just knows when one is actually pushing on the accellerator pedal. In heavy winter footwear, this is not possible through direct foot feel. The only time I ever had trouble was on polished glare ice at a stop sign. For the more southerly readers, this ice is so slick, its not uncommon for drivers to get out of a car onto it, and promptly fall on their rear ends. Even so, I eventually was able to walk the car off that patch of ice with repeated pedal applications. And the SUV behind me proceeded to have the exact same difficulty.

Operationally, one needs to observe the car motion, and assume one is pushing on the pedal, when the car begins to move forward slowly. Even when one cannot actually feel the pedal.

 

Zero friction is the limiting case. While it doesn't exist in nature, several driving surfaces provide a good approximation. The point still stands: if you don't have friction, traction control cannot make up for it. Good traction control will help take advantage of what traction there is, but it can't overcome physics. 100% utilization of nearly zero traction still produces nearly zero thrust. In these situations, only better driving conditions, chains, or better tires will help.

I point this out because posters routinely complain about traction control in situations where it could never help. This shows a lack of experience with real winter driving, and serves only to cloud the discussion about the effectiveness of the Prius traction control.

On the other hand, you make an excellent point about the effectiveness of the Prius traction control in situations where it should help. Traction control on the Gen II is a misnomer; it's really there to protect the HSD, not improve traction. Apparently it's much better on the Gen III, but I have no personal experience.

Tom

 

Actually I'm in Manitoba, but I agree with the rest of your comments

My 2004 Prius running aggressive studded winter tires, easily blew the doors off pickups and suv's running "all season" tires on glare ice, once the light turned green.

I'd look in the rear view and their mouths were open in amazement, while their vehicle was spinning

If I had had the Michelin Harmony tires on, I would have been motionless at the same green light

I usually wait for the first storm before changing my FJ over to the factory studded Nokian winter tires. I normally run Goodyear Fortera TripleTred, which *meets* the RMA "snowflake" standard

There is a day and night difference among the two tires. My FJ has "real" traction control in that the brake is applied to a spinning rear tire, or in 4H more than one spinning tire

Without any weight in the rear cargo area, the FJ will stuggle a bit at a green light. Throw 500 lbs in the rear, it is better but the traction control still applies the brake a lot.

Throw on the factory studded tires, and I never use 4H on city streets or the highway. It's rock solid.

Though i do have to worry about cars and pickups sliding into me at red lights. If I see a vehicle obviously sliding at me, and if there is no cross traffic, I go through the red light

I simply don't understand how morons raised in this climate and taught to drive in winter will drive as if they just stepped off a plane from Miami

 

This looks like a steep driveway. I think the prius did pretty well.

 

The Traction control problem is still carried over to the 2010 IV Prius. The car is dangerous in the snow…period!! I’ll drive my jeep to work…at least I can get there without coming to a stop due to the traction control not allowing the vehicle to move. My tires have a ¼ inch of tread left on them and from the sound of all the write ups on this web site…tires are not going to fix the problem totally!! I see why Toyota is falling from the number one slot!!

 

Are they snow tires? If not I do not know what you are complaining about. Get new tires!

 

Sorry I don't agree wrt the Gen III. Look at the previous video the Gen III does fine - I cannot comment on a Gen II. I am from Canada but currently live in Texas. We had 4 inches of snow then melted and re-froze to ice this weekend and I had to climb a hill covered in ice and snow like the one showed in the video and yes the traction control light came on but the Prius was rock solid with some wheel spin but mitigated by the TSC and up it climbed no issue. I then watched a 4 wheel drive F250 slide straight into the curb. Also this was on 11K mile stock tires - nothing special.

 

where are the direct side by side compares with "safer" cars? C'mon all you complainers, find some friends with 'normal' cars, run them up the same hills that the "dangerous" Prius can't handle and let's see where the problems are. Bring it on.

 

Yeah? Their winter capacity is worn out. Mine have slightly more than your 20k miles, and are now s**t for winter, of which I was strongly reminded just two days ago. These were much better last winter.

I've never had all-season tires provide 'adequate' traction for my winter needs, on any car, for even half their tread life. Then they must be banished to the other seasons, replaced with fresh tires for winter. My Prius OEM tires have now reached that point. Many drivers in other locations and situations can't get by with A/S tires at all.

In another post, you indicated that the TC light was flashing the whole time. Did you reduce the throttle enough to make the light go out? If not, you will get stuck.

Even with worn-out tires, my TC readily allowed me to climb the back hill, past two other stuck rigs already getting towing assistance, reaching the top as the sand truck arrived from the other direction.

 

ARE YOU KIDDING??? did you see the video!!! What more proof do you want than that. I think the problem is your driving, not the prius traction control.

Here is another video,

 

Some Prius owners appear to have zero issues with "all season" tires. My '04 was helpless with such tires but a great winter car with aggressive studded winter tires

One thing not discussed or poorly discussed is how almost every other car with "traction control" also has a button to dump the electronic nannies so one can handle bad winter conditions or getting unstuck better

BTW the '07 to '09 FJ also has a traction control system, but a "real" one in that the brake is applied to a spinning wheel, even in 4wd. Some complain about how it works, being too aggressive, not something I have noticed as it generally works the way I would want it to work

But that generation FJ there was no easy way to defeat the TC. Some came up with a hack to put in a switch to ground or disconnect one of the wheel speed sensors, tricking the computer into thinking there was a failure of the speed sensor. Under such conditions the traction control is automatically disabled

The 2010 FJ comes with a TC defeat button. When applied there is a warning light on the dash and a warning chime

 

The Prius has been around for about 8 years now. Never has there been so much bitching and moaning about the car since the establishment decided to knock Toyota down a few notches to help out the semi-clueless American car industy.

The Prius is still the best damn car in the World. That's probably it's biggest problem.

 

Traction control IS a legitimate problem but only on very steep, slipery slopes.

I've learned how to disable traction control on the Prius. Do a google search or search this board to find out how to do. This has allowed me to climb snowy hills that I could not with traction control enabled.

I was close to trading my Prius before I found out how to disable traction control.

-Brad

 

The method for disabling the traction control is quite convoluted but it IS possible. I have never tried it but I'd be tempted to. The problem is that is too sensitive. As all of us "experts" are aware, Toyota programmed the TC to be highly invasive to protect the hybrid drivetrain. I think that it is too protective and invasive. Even on flat and level surfaces when it is snowing, it comes on too often. I suppose if you have a very good dedicated snow tire, it would be less intrusive.

 

"...to protect the drive train...."

No, the TC in any FWD or F/awd will nowadays be programmed to be HYPERACTIVE, VIGILANT, to protect YOU...!

Loss of traction on the front drive, and stearing, wheels is a very serious matter and must be addressed URGENTLY given the potential for loss of directional control leading to an injury, or even deadly, accident.

As an additional matter we all know is that these HSD systems have a rather unusual level of low end, low speed, torque due to the electric motor drive aspects.

Word is that Infiniti is soon bringing a RWD hybrid to market. It will be interesting to compare TC activity between the two drive concepts.

 

Hi All,


My opinion is we have a PIO-like problem with the Prius. Many people just do not have the control sensitivity, or willingness to learn or apply such control sensitivity to avoid slipping on slick surfaces, with the high torque capability of the Prius at slow speeds. The issue is not the hardware, the issue is the complete indifference people have to the hardware being different. In the early days of faster-than-sound flight, it was found that big tail surfaces were needed to control a high-speed jet. But, at low speed, these larger surfaces required very small changes to execute low speed manuevers. It became such an extreme situation, that pilots were over-correcting back and forth, and introducing Pilot Induced Oscilation, or PIO to the plane's attitude.

In the High Torque Prius on slippery surfaces, drivers are inducing traction loss. So, we have DITL (Driver Induced Traction Loss). The TC just reacts to the traction loss, not the other way round.

The ECO mode in the Gen 3 is providing a similar function as the analog computers used in the early 60's in supersonic aircraft to tame the PIO problem. Although, one has to switch it in.

 

Well then, if the problem is well understood as such, what is Toyota's official recommendation on how this vehicle should be driven under such conditions in each model year (perhaps software revision as well) of the Prius and in each operational mode (ECO etc) it has ?

Do you have that information ?

But you might be right in saying the Prius is just too complicated and difficult to drive for an average driver, which by the way is the very subject of this thread.

 

I have experienced the Prius traction control problem several times in less troublesome situations, like loose gravel and snow packed roads, and was concerned about it. However, yesterday I parked in a snowpacked parking lot that has an incline to get out. Our 2007 Prius would power down to the extent that the front wheels would barely move. To make the story short, we ended up having to leave the car there overnight and walk home, in the dark at +5F. I got a couple of friends to push and we managed to get the car home today.

This MAJOR FLAW has greatly diminished my love for the Prius. I would definitely not buy another one unless this problem is fixed. The car is useless in any kind of slick/loose conditions. There are many situations in town, if the car can't climb in snow up an incline, I would be in a serious mess, with cars backed up behind me. From now on, if the roads are slick at all, the Prius stays in the garage.

 

What tires are you running? Were there other stuck cars around?