Traction Control

Qb: Sorry if I misinterpreted the power reduction as power shift. I based the comment off a discussion I had with the service tech at the dealer. Either way, the car has ample torque to get up a hill like that. For a modern vehicle to just "give up" is absurd.

 

I agree. My first winter with my Prius, before I put on the winter tires, it "gave up" in the middle of an intersection. Damn near got t-boned too.

I'm sure Toyota engineers could have provided a button to provide low-speed Trac defeat, or at least allowed minor wheelspin.

If you're on the gravel hill, or stuck in snow, that would help a lot

 

Yesterday I took my 2008 into the dealer for its first 5000 mi service. I was talking to a tech about the traction control issue and he insisted that removing the fuse for the ABS would defeat the traction control. I'm skeptical. Anyone ever heard of this or better yet have experience with it?

 

A fuse blows and the motors can then destroy themselves? That sounds like an unlikely design, but I'm not gonna try the experiment.

 

FWIW on this subject, my nephew in Minnesota has had a Prius since 2001, and he told me the VSC option is important to have for good winter traction.

 

VSC is not traction contol and it is not part of the issue. The thought behind temporarily disabling traction control is to get around the complete power loss experienced when you - for instance - climb a steep gravel hill. I think the issue has been sufficiently beaten to death. My apologies for bringing it up again. Solution = get the best tires you can buy.

 

VSC greatly improves winter safety and handling, but is not related to traction control. From a conceptual point, yes, but the systems are not interconnected or related in any physical way.

Tom

 

When reading through this thread, many people state that disabling the traction control would allow the electric motors to potentially damage themselves. I'm curious why this is. Could someone explain this to me?

It is my understanding the throttle is simply a request made to a computer. Why couldn't the computers allow the motors to spin the tires up to a safe point and just ignore any throttle requests that would potentially cause damage?

I've only had my Prius for just over three months and have not experienced any problems with the traction control. I'm just amazed by the simple complexity of the Prius hybrid system and trying to learn as much about it as I can.

edit:
I could see damage from overspeed in the motors if they were DC. But I thought the electric motors used in the Prius are three phase. They will only spin as fast as the inverter will drive them, regardless of how light the load is. Will the inverter drive the motors to an overspeed condition?

 

The Traction Control system on my 2008 Toyota Prius is worthless. I have a steep gravel driveway that is extremely hard to climb due to the unnecessary engine cut outs, especially if there is any extra weight in the rear of the car. The engines quit when the computer senses any type of slippage; worse in the summer when gravel is dry. Also there are very noticeable engine cut outs when just going over bumps on level pavement. My previous Prius, a 2002, would slip a bit on the same driveway but I had much more control over the car and the speed compared to the new 2008. Heavier tires with more rubber on the road made little difference with the 2002; I expect the same when I get better tires on the 2008. Had I known about the problem with this earlier, as I have just found reported in this forum, I would not have purchased this car. I think Toyota should recall and correct these cars' problem. Perhaps a trade in on a 2009 model with optional on/off Traction Control as found in many other vehicles would work for me and others. The trade in could be prorated like the warranty on tires. But I should not have to take a big loss on selling the car after disclosing this problem to a potential buyer; Toyota should eat that loss. The argument that shutting down the power to the front wheels in all cases of slippage is ridiculous. If the issue of over spinning the electric motor is the reason for this system, as pointed out in some of the threads here, how did the earlier years of Prius, such as the 2002 I had, get by without any such issues coming forward? I am now considering selling my 2008 Prius for something that works safely for me. Toyota should have informed the buying public of this "limitation" once it became an issue back in 2004 instead of denying the problem. I would join a class action suit against Toyota to get them to make this right. I appreciate Toyota for being on the cutting edge of technology and making sensible cars for our times but Toyota also has to take responsibility for their mistakes along the way. This Traction Control system is the worst thing to come along in a long time. Thank you for this forum.

 

Interesting. Back when we still had a bit of snow around, I test drove a 2008. Compared to my 2004, the Trac was light years better behaved

The only way for me to get reliable winter traction out of my Prius is to run very aggressive Euro style studded winter tires.

Your situation with the gravel driveway, not sure what to suggest. Kind of obvious you can't slap on aggressive off road tires just to climb a driveway your previous Prius had no trouble with.

Toyota also doesn't have a Trac cancel switch for their FJ. However, the Trac in my FJ is *very* well behaved. I only wish Toyota would equip some sort of temporary defeat button that would drasticaly detune the Trac. It could be programmed to automatically disengage if the indicated speed exceeds 50 km/h

 

The new trac control works much better than the old 2004, as jayman reports in the previous post. I have a 2006, with the same traction control you have. It was terrible on gravel roads until I replaced the OEM Goodyear Lack-of-Integrity tires. With Micheline MXV4+ Energy tires it does much better, with no loss of mileage. Even so, Toyota should be able to provide a limited slip mode instead of the all-or-nothing mode it has now.

Tom

 

snip
The only way for me to get reliable winter traction out of my Prius is to run very aggressive Euro style studded winter tires.
snip


I haven't had my 09 Prius through a SE Michigan winter yet, but I'm ready with Michelin X-Ice snow tires.

But, I have to agree with you that nothing compares to a good set of studded snow tires. A number of years back, that's all I ran during upstate NY winters. They handled about any situation.

Michigan doesn't allow them, saying they tear up the road (an opinion many who've analyzed it disagree with). Heck, if they're that worried, put a surcharge on the annual vehicle registration for those wanting to use studs and put it into a road maintenance fund ... and provide a sticker to that effect. If they don't get many takers, then there must not be much "damage" from the few cars with studs. If there are a lot of takers, then they'll have more money to fix the supposed damage. The real reason for poor interstate road condition in Michigan is, I'm told, that Michigan allows much heavier weight loads for 18 wheelers which stresses road surfaces which aren't as robust as it should be.

I know an extra fee could be unfair to those with limited incomes, but they could waive the extra fee for those who qualify as limited income.

 

GOOD studless tires should be better than studs. The Blizzaks used to outperform the studs on anything but pure ice where the studs had a bit better grip.
But as I recall a couple years ago the Blizzaks were to the point of surpassing studs even on bare ice.

Technological or Traditional Traction For Ice and Packed Snow?

Levi

 

This statement is technically incorrect, but true from a practical perspective. The State of Michigan does allow studded snow tires, but only those demonstrated by the manufacturer to meet certain road wear standards. To date no tire manufacturer has certified a studded tire for use in Michigan, so effectively you can't use them.

Tom

 

I recently noticed my 2007 having traction issues on wet pavement. 52,000 miles on the factory tires. I got a new set of hydroedges and didn't stall at the same stop sign.

The stalling is very scary when pulling into traffic. I hope this fixes it for the 80,000 they say they're good for.

 

Hi Bob, I live in England and have the European 2004 Prius, I dont know if this will work with your car but I can turn Trac Control off with the following procedure, all within 60 seconds, 1/ press start button twice to select accessories 2/ press gas pedal to the floor and back fully two times 3/press brake select N (neutral) 4/ repeat step 2 5/press P (park) once 6/ repeat step 2 7/ press brake pedal then start button. You should have a flashing red car top left of hybrid display screen. Traction Control is now dissabled. Make sure you re-boot your car to return to normal after you have got "unstuck". Hope works for you good luck and best regards Bob Robertod

 

This is exactly the same sequence suggested on page one of this thread for US Prius.

 

I reported the excessive traction control response to NHTSA as a safety defect. It places any reasonable driver at risk, as most have not expereinced anything like this ocomplete power cutout at the first hint of tire slip on any other car.
That being said, I put on a set of Nokian hakkapeliitta snow tires and noticed a very significant improvement. They are great in the snow, and even help on simply wet roads. I recommend them highly and have not noticed a significant penalty in terms of wet/dry braking or handling. I am considering running them year-round, because to me they turn a dangerous situation into a manageable one. And no, I do not work for Nokian. As in most cases, the OEM tires are usually worth no more than the minimal money the manuafactuer pays for them, and upgrading tires is often the best first "mod" an owner can make. If you live in snow country this car should not be driven on all-season tires in my opinion. Good luck to you all!

 

Umm... Yeah, that's true for about any vehicle... If you live where the conditions are slick, and you consider that dangerous then you would be well advised to use tires that are made for those conditions to regain traction.
I used the Blizzaks on my 03' Prius and never had a time I couldn't get to work at 4am in upstate NY on uplowed roads with hills. (there was one time when the road was covered in a sheet of ice and I had to take an alternate route because I couldn't go UPhill on ice).
Just did it last year with my 04' Prius. The only time I didn't make it was when I was driving through more than 6 inches of wet heavy snow and the Prius was plowing through it. It DID drive through it, but didn't make it after making a pile in front of it and then trying to go uphill. But as soon as I cleared the driveway it drove itself out and on the roads that were also unplowed. I would NOT have made it though those conditions on any other FWD car with lousy tires either(and yes, most all season tires are LOUSY in snow/ice). I also wouldn't be real keen on trying it in my wife's AWD Subaru if she didn't have Blizzaks as well.

I will agree, that a lot of people drive like idiots and have not a clue as to what is going on with their cars, but I'm still failing to see how the Prius is really any different, especially since so many new cars have traction control these days... I had plenty of days in the winter when I was in high school with an 87' Dodge Colt on all season tires, and if I hit the gas to go, the wheels just spin and after a while it starts moving... Yeah, it's a different sensation than when the Prius cuts power, but the result is the same. You hit the gas and there's not enough traction and it takes longer to get going... Solution is the same either way. Increase traction and don't be pushing the go pedal farther than you have traction available...

 

The Prius difference is that even a tiny bit of wheel slip immediately cuts all power. You can be pulling out of a side street into traffic in the rain and all of a sudden you are stopped dead and have to wait a moment before the car will move again. Do that in traffic with oncoming cars, trying to slip into one of the few available gaps, and it'll get your heart beating fast and earn you a few horns. I have driven six other cars with traction control and NONE would react so strongly and readily in such a situation. The other difference? In each of those cars traction control could be temporarily turned off with a dashboard switch (as it can in my 2010 Rav). But not in our 2005 Prius! Yes, one can learn not to undertake driving maneuvers that result in even a tiny bit of wheel slip, but this is not something one would have to do in a better-engineered car. The Prius should have a rev limiter as needed for the power system, but should not cut power altogether for several moments. This is dangerous, and there is no warning in the manual that I can find--we each find out the hard way. I'm betting Toyota has corrected this in subsequent Prius models, sure sign that they recognized it as a problem (but no help for us with the earlier generation cars). In my opinion it should be a recall item.