can you disable the tration controll?

<div class='quotetop'>QUOTE(leedsprius @ Mar 5 2007, 08:22 AM) [snapback]400290[/snapback]</div>

You can, but you're not supposed to drive with it disabled, be very sure not to overspeed things, If you end up using this let us know how it works in your situation...
http://www.eaa-phev.org/wiki/Prius_Modific...raction_Control

== Disabling Traction Control ==
'''WARNING: The shop manual apparently states in no uncertain terms that this procedure must NOT be used to drive the car as damage to the transmission could occur due to traction control being defeated.'''
* Follow the sequence below (quickly - within 60 seconds)
* Set Ign switch to ON, not READY (Power button twice, no brake)
* While still in "P" fully depress the gas pedal two times.
* Select "N" fully depress the gas pedal two times.
* Select "P" fully depress the gas pedal two times.
(LCD display will indicate a !Car! in upper left corner of screen)
* Turn key directly to "start" to start the engine (brake+start button)
It forces the ICE to run continuously and defeats the traction control system. Normal operation returns after turn off and reboot. Unlike EV-Mode this is '''strictly a diagnostic function and should not be used under normal situations'''. Thanks to Peter Rawlinson for posting this on the [http://autos.groups.yahoo.com/group/Prius_Technical_Stuff/message/13315 Yahoo Prius_Technical_Stuff] group. More discussions can be found here: [http://priuschat.com/Thinking-about-disconnecting-traction-control-t12860.html], [http://autos.groups.yahoo.com/group/Prius-2G/message/46367], [http://autos.groups.yahoo.com/group/toyota-prius/message/90032].

 

Thanks a ton for posting this. Living in the mountains, I need to spin my wheels to get up steep grades when they are covered in snow and ice. I barely made it up "the hill" the other day with the traction control on. Today it just dumped another 5 inches ontop of what was left, and I had no problems getting up the hill with the traction control off. Drives just like my civic when I need it which just adds to the prius perfection!

 

Just don't "toast" your HSD transmission. (and then come back complaining)

 

Well I put getting home as a higher priority.

Also I do not understand how this would possibly kill the HSD. As long as you are not artificially spinning the motors faster than they would be otherwise allowed to, it should work just as if you were driving the wheel speed's speed on normal pavement. Going ~30mph with wheel speed around 35-38mph, doesnt seem like a big deal.

If anyone knows the actual reason, I would love to hear it.

 

Rapid changes in wheel speed can cause MG1 to run at excessive speed, and also couple shock loads to the PSD. The real risk is spinning the tires at high speed, then having them bite suddenly.

Tom

 

All I know is the engineers who designed the HSD put traction control on all Prius to protect the components of the drive train. They know why they did it and I hope you don't find out through your actions.
Have you tried different tyres, like ones designed for snow and ice?
How about different driving techniques that don't spin wheels?
Lower tyre pressures, or maybe higher?

If you toast your HSD transmission you might take a long time getting anywhere.

 

There are no driving techniques available to get up a mountain covered with ice where you lose all wheel power for a quarter second everytime. As soon as that happens and you are on a 40% incline, you go backwards.

 

First, what tires are on your Prius. If they are Goodyear Integrity Tires, get rid of them and get good tires (I recommend Nokian WRg2).

Second, I agree that the so-called Traction Control is poorly implemented in our Prii. Toyota could have protected the HSD by incorporating torque limiting clutches in the half shafts (like the one between the ICE and the HSD). Traction control should use the brakes to limit wheel spin, not removing forward acceleration. When merging into traffic, this can be a hazard (being hit broadside is NOT a good thing.).

JeffD

 

I agree with checking on the tires. The Goodyears that came with my 2005 Prius were
like slicks in the snow and wore out after 30,000 miles. I put Goodyear Assurance tires on and at 35,000 miles on them I was able to blast past everyone in our many 1 foot plus snowfalls we had this year. Had to get to work and the ski hill. The Prius is great in the snow - front wheel drive, thin tires and under-powered (OK not over-powered).
I agree their traction control leaves a lot to be desired but with the Assurance tires it has become a non-issue in the snow.

 

It does on the 2010. Toyota has learned from the Gen II.

Tom

 

My tires are regular crappy OEM. Driving around town and most of the time, it is fine. Yeah they slip everywhere, but I can control it just fine. It wont make any difference to get up the hill (the mountain) with different tires/tyres. My old civic has Michelin X-ICE tires which are awesome, but same thing going up the mountain. When you are driving up such a steep incline with no grip, the only thing to do is maintain wheel speed and hope to get up the steepest parts. We have a 4wd Lexus RX as well, and its traction control beeps everytime, but it is handled much better and works fine. Still takes speed to get up. This is the type of road where people regularly get stranded and ditch their cars along the side because they just cannot get up. It is not a little rolling hill, it is a mountain. After a decade of driving up this route in cars with various tires and various transmissions, the only solution is speed and maintaining it. I can get up in my civic while 4wd trucks are going sideways sliding back down the hill because they let off the gas for a second and will have to go back to the bottom and start over.

I am glad toyota fixed this in the Gen III. Does anyone know how it compares to the Lexus traction control?

 

Traction is traction, and if you don't have it, you won't move. Saying that bad tires don't make any difference is silly.

Tom

 

Correct driving techique 101 on snow and ice is to NEVER spin your tires. Don't blame the car if you are driving like a high school student. It sounds like you need to get rid of the OEM three season tires and get some snow tires.

 

I never meant this to derail the thread to be a winter driving discussion, but quite frankly if you do not live on a mountain, you have no idea what you are talking about. Ice is ice. Now put it at a steep incline, and better tires will not help you at all unless they are studded. If all you do is drive around town and hills that are a few hundred feet elevation changes, then yeah snow tires make a difference. And I have them on my other vehicles for when I am driving around town. I can control my cars better than most on any surface, and I am telling you going up a mountain from ~6800ft to ~10000ft on a road that barely moves side to side (not a winding mountain pass that zig-zags up the hill) cannot be done with a sudden loss of acceleration. There are vehicles with chains on that get stuck. The majority of people end up going sideways down the hill when they are trying to go up. They lose power, car goes sideways and glides down bumping curbs until it gets to the bottom or hits something else. This is a road they close when the weather gets too bad. If you think you can beat this mountain driving slowly where everybody that his lived on it for many years knows you cannot, then I invite you to try, but you will fail miserably even with a 4wd vehicle. The only exception is studded tires or chains with a moderately aggressive approach, or regular tires of any kind with an extremely aggressive approach.

We have had over a foot of snow over the past week as well, and it is the end of March. We will have a few more storms before the winter is over (in July around here)...

 

I don't think anyone here is arguing the point that cutting power will help you go up a slippery hill. Momentum is very key when going uphill in low traction situations, and once you lose that momentum you are not likely to get started again.

The point several people are trying to make is that without traction you will not move uphill or even across the flat. You have to have some traction or you can't move at all, which is why studs help on ice. All things being equal, the more traction you have the better you will do.

Spinning tires only help in two situations:

1) Controlled spin, where the tires turn slightly faster than the car is moving. This is very similar to the controlled slip situation used by locomotives going up steep grades. This works as long as you can keep the contact area in a plastic state of friction. Higher speed slipping moves into the area of dynamic friction, which is much less than static friction, reducing traction.

2) Burning through to dry ground. In some cases you have a thin layer of slippery stuff, and spinning the tires will melt this layer and let the tires grip the better surface below.

Tom

 

Having had to drive in this situation for several years [not of late thank you, and never with my Prius thank you again] I think many are missing the point.

At least in my experience, it's >not< that the spinning wheels help anything when there is no traction. The point is that most of the road has some traction -- only random spots have no traction -- and what kills the Prius is that when it hits one of those random spots, it just goes into limp mode -- so even if it gets over the bad spot to where it DOES have traction, forward drive has already been cut -- leaving you stuck, or going sideways or going backward.

I almost consider it false advertising to call it 'traction control' -- when it is really just 'drive train protection'.

 

Re: can you disable the traction control?

Well said. :rockon:

This is a marketing technique: transforming a flaw into a customer "benefit"...

 

I understand that point, and even made it myself. Momentum is very, very important when going up a slippery hill. Our roads are often very slippery, and not just in places. We can go for weeks at a time without seeing the road surface.

It is true that the main purpose of Gen II traction control is to protect the HSD, especially before 2006. Starting with 2006 the traction control system allows for controlled wheel spin, which I often use in the winter. If you press too hard on the gas you can get into the power pulsations that you describe, but obviously you don't want to do that.

You seem to miss my point, which is that without traction, it makes no difference what sort of traction control you have. If you don't have traction, you aren't going to move, unless you are sliding. This isn't really a profound point, but sometimes people miss the obvious and complain about traction control when no wheeled vehicle would work. I'm not saying your situation is one of those, but many other people read these threads.

I'm not a fan of the Gen II traction control system. It's a compromise at best. It's better with the 2006 and later, but it's not great. The Gen III system is reported to be much better, and is traction control in the true sense.

Tom

 

I'm not missing your point at all -- it's just that situations where there is 'no traction' are much less frequent than situations where there are 'slippery spots'.

Saying 'it makes no difference what sort of traction control you have' can be equally misleading to those 'many other people' reading these threads -- particularly people who are accustomed to how 'non-Prius' traction control behaves when you get past the slippery spot. Few, if any, of those 'other' cars will leave you the way the Prius leaves you at that point.

That said, I would contend that it does matter what type of traction control you have under most normal driving conditions -- particularly if you are already moving.