Does ECU Upgrade Fix 04/05 Traction Control?

My new 08 slid backwards on me a couple days ago.

 

I have never had any traction control problems with our '05 (although I don't dispute that other people have had problems). I guess my point is that just because someone with an '06 says they haven't had problems with traction control doesn't mean that there car has been "fixed" compared to the '04 or '05; it may just be that they haven't been in as extreme conditions as the people who have experienced problems.

 

My traction control engages regularly (I'm a petrol head) and I have never heard of putting the Prius into reverse to get going once it does? I can even get the tyres to squeal when turning right from stationary (equal to turning left for you) right through the turn. I have a 2004 which should be the worst. Traction control cuts in when I accelerate over round access covers in the road. If traction control cuts in, back off and accelerate smoothly. Try to keep even pressure on each of the front wheels, avoid holes especially on slipery slopes.

High tyre pressure reduces traction.

 

Yup. My 05 stops sometimes when I accelerate turning right (right wheel spins a bit), like when merging into a street from a parking lot, etc. Pretty disconcerting at times. Being aware of it helps, but I'd like to see a "fix".

 

I think it's important to clarify a couple of points

1. Tideland Prius did *not* have an "upgrade" done to his Prius. He was in for a required ECU flash and the dealership fried his computer.

2. Not all 2004-2005 Prius cars experience the dreaded lack of Trac issue.

My 2004 Prius appears to have the hypersensitive Trac and my first winter, I came very close to getting rid of the car. I knew I would be getting winter tires anyway, and thought I would try studless tires to see if their grip really did make studded tires obsolete

Well, the Dunlop Graspic DS-2 tires really did help a lot, but I was still having problems at icy intersections. Once the temp dips much below -10 F, deicing salt stops working, so an intersection can stay icy for weeks. They can spread sand around, but a windy day takes care of that too

One thing about the Graspic winter tires is they handled very well on dry roads. Very little squirm was evident, which is usually a problem with the soft tread compound in studless tires

I found somebody at the office who was willing to buy my Graspic tires, and got a good deal on some Yokohama Ice Guard 10 tires. They were slightly better on ice, but I was still having problems. They also had a lot of wander at highway speeds

Note that the Graspic and the Ice Guard were light years better than the Michelin Harmony "all season" tires I have on the car

I then got fed up, and went back to the studded tires I used in the past. Canadian Tire started carrying a new tire last year called the Goodyear Nordic. This is the same tire as the Goodyear Ultra Grip 500 sold in the EU

http://eu.goodyear.com/home_en/tires/repository/UltraGrip500/index.jsp?page=benefits

If you click on Profile a Flash presentation loads. When studded, these tires are outstanding on ice and great in snow. Until the car itself bogs down iin deep drifted snow, then the wheels refuse to turn

For my FJ Cruiser I priced factory studded Nokian Hakkapeliitta Sport Utility 5 but the price per tire made my jaw drop. I chose Toyo Open Country G-02 Plus studless winter tires. Overall, excellent snow traction, but on ice my Prius still has the advantage. I may go to Cooper Discoverer M+S studded truck tires

My FJ also has Trac and VSC. However, the Trac works differently than the Prius. If a rear wheel spins on my FJ, the brake is applied to that wheel. Then the power is reduced. The Trac and VSC tuning appears more "sporty" than the Prius, and is never intrusive. I never have to drive in 4H on snow or ice.

Note that there will be Prius Apologists who will blame your winter driving skills - or lack thereof - to deflect blame from the car. Even if you're middle aged and learned to drive in real winter conditions, they will find fault with you.

After all, [Sarcasm Mode ON] their Prius can charge up glare ice hills on bald summer tires [Sarcasm Mode OFF]

 

The problem with "traction control" on the Prius is that it has squat to do with providing traction. All the engineers wanted was a way to keep the motor-generators from over-spinning in the event that a wheel starts spinning, which is why the first iteration did what it did. If wheel spins, cancel power.

The change for the '06+ cars (based on last winter's experience) is that the system no longer gives up. Now it's "If wheel spins, cancel power. Now try again." The effect is..."unique"...but not so bad if you have the right tires. If you get stuck you just have to put your foot on the accelerator and wait. It'll stop and start a few times a second and slowly grind its way out. This screwed me up the first time I thought I was stuck because my reaction was to reduce power and try again with less accelerator pressure. But if you keep doing that you'll never move.

 

Me too

This hasn't been a frequent problem on my 05, but when it happens, it's scary. This is a different animal than the experience of hitting a pothole or bit gravel and feeling briefly "out of control" even when you're not.

I experienced it last winter trying to get out of a slushy snowshoeing parking lot onto a 55 MPH busy highway (26 up near Government Camp for you NW folks). I was OK moving slowly through the lot, keeping the torque down, but almost didn't make it onto the highway because halfway on the roadway, the car totally lost power to the drive wheels, and I was nearly hit by an oncoming vehicle. No, I hadn't gunned it or anything, just waited for a big enough break in the traffic to be able to pull in slowly and accelerate once on the wet but snow-free roadway headed uphill. I was in total TRAC STOP for several seconds (seemed like longer in my panic) until I put it in P and back into D and was able to get out of the lot. Adrenaline is good for you, right?

I do understand that they don't want us to able to hurt the car, but at the risk of hurting the occupants, it does seem that an update on these vehicles is in order. Being able to "reset" the traction control without having to change gears.

 

Living in North Dakota as I did when I got my 2004 Prius, and in Spokane now, I have no experience driving up really steep icy roads. But I'll describe the behavior of mine on ice anyway:

It was common in Fargo to have extremely slippery ice at some intersections. A base of compacted snow gets melted, and then freezes, and the cars spin their tires, leaving a layer of warm, soft ice or water over a base of ice. Extremely slippery!

Conventional cars spin their wheels and fishtail before finally moving into the intersection and on through. With my old Civic I had to touch the accelerator very lightly to try not to spin the wheels.

But with my 2004 Prius I floored the pedal and held it there. At first nothing seems to happen. Then the car slowly begins to move, picks up speed gradually, and moves on through the intersection.

But even though it moved slowly, it still started and moved faster than most other cars at the same intersection. It clearly did not cut power completely and stop. It greatly reduced power as the wheels spun, or maybe it cut and re-applied power. But I didn't have to do anything but hold the pedal to the floor, and the computer would apply the right amount of power, better than I was able to do with my old conventional car.

My car was built in December, 2003, and the ECU was re-flashed once or twice, under the various recalls or whatever they called those less-than-recall notices they sent us in the early days.

The first winter I drove on the OEM tires, and going into the second winter (I think it was) I switched to the Michelin HydroEdge tires.

 

I was constantly breaking the tires loose while making turns, and it's been dangerous when this happens and you're trying to merge into 50 mph traffic.

I bought some wider, stickier 17" wheels and the problem went away. I took a 3 mpg hit but the sense of security is well worth it.

This is for my 05, on my 07 (still on stock tires) it's a little better.

 

nyprius,

Here is the video of my 06 prius trying to get out.... You can see the traction control light coming on with MPH never exeeding 10 MPH (if I remember correctly) while the car is not moving.

Does your Prius' TC behave like that?

 

yeah i was stuck on a hill (and i didn't even have to travel for 25 meters to get stuck it was pretty sad!)

brand new all seasons too! but the 48 psi tires sure didn't help ahhaha lucky i got chumps in the passenger seats to help me push keke.

Although when they do help me push i have to heave ho along with them, let off the accel pad, and when they push press it ever so slighty to grip and once i grip then i gas some more until i can roll for a couple of km/hr if you even make it pass that stage consider yourself lucky! It took me over 10 minutes to figure that out.