2013 PRIUS 1.8L(A) Luxury,both Steering wheel & brake fail at the same time while on driving mode.

Also be aware to shutoff the engine in worse case scenarios requires pushing the Power button for about 4 seconds.

If this was done by operator error or by a kid playing with the dash, then the car will shut off including power steering and regenerative braking. So the car becomes a lot harder to steer and brake but it should still do both but nowhere as easy. Using the supplemental parking brake was the right thing to do but it can cause loss of control at high speeds.

So while an accidental shutdown scenario does not quite fit with the steering feeling like a "toy", it might have happened and maybe the adrenalin rush caused a little juggling of the sequence. Perry Mason proved this more than once.

 

Light, unresponsive steering together with unresponsive brakes that later cannot be reproduced suggest the vehicle was sliding. With a complete loss of traction, assistive systems such as VSC, ABS, TRAC would be ineffective.
What were the weather conditions when this occurred? You state that this occurred on a bridge. What is the road surface: asphalt, concrete, or steel? Is it possible that there was a slippery spot on the roadway?
The condition of your tires can have a major effect on traction. If they are worn, under or over inflated, that can result in unexpected handling.
By the way, momentarily pressing "P" while driving over about 10km/h will have no effect, to prevent an inadvertent bump of the button from shifting you out of gear. Press and hold "P" for over two seconds and it will shift to Park if you are below about 10km/h, or neutral if over about 10km/h.

 

Questions to The OP.


Are you sure you didn't brake first, then notice the symptoms?
What condition are your tires in?
Could the surface of the bridge be different or considered slick? Or did you hit a slick spot?
Did the VSC symbol illuminate?

I've had similar braking incidents. Was told it was the VSC kicking in to maintain "control" by allowing slipping wheels to turn. NOT skid.

 

Sounds like a very dangerous scenario.
Where you live, I don't know what type of dealership or support options you may or may not have.

Do you know if they ran a computer check and/or checked for error codes?
Plus was a actual physical inspection done of both the steering and braking systems?

At the very, very minimum you have a right to know what was done to your vehicle once brought in for this problem. And it should be more than just a tech trying to duplicate the symptoms.

Makes me nervous about my two braking incidents. Which after having my vehicle checked out I was similarly told that it checked out and that it was safe to drive...but they couldn't duplicate the symptoms. My brake foot pedal also went all the way to the floor, and it felt very much like I simply lost most of my braking power. Again, what I was told was that it was the VSC kicking in, and working to keep the vehicle under control.

In both my incidents, they did happen in winter, and in slick conditions. I guess I'm willing for now to accept that this is simply the normal action of the VSC when it feels the wheels slipping AND you are trying to brake.

I don't think I had any steering issue. Although in both cases my focus was on trying to stop. And I would say my incidents were predicated by my braking first. So unlike your description, it wasn't just a matter of driving along, and then suddenly it happened.

Best of luck...and please be very cautious. You deserve answers as to what happened.

 

Your service center may be very good at routine maintenance. But throw in a hybrid and an event like you described and they may not have the experience to diagnose it.

 

Yes, I have experienced this before, and it is NOT a fault with the car.

You experienced a SKID! The orange flashing light is the SKID WARNING LIGHT. Suggest you check this out in your user manual.

I note your comment that you are not very technically competent with the Prius, but IMHO it is any owner's responsibility to be aware of what the warning lights mean, when you first start driving the car, and especially after the warning light has operated to warn you of something.

Sometimes road surfaces behave unpredictably, if tar is soft in hot weather (and concrete roads may still have tar at the joints of the concrete surfaces), or if there has been some sort of leak or spillage of a slippery substance such as oil. Motor cyclists are especially vulnerable to this risk, and fatal accidents have resulted.

 

P.S. Never press the P button while the vehicle is moving. It cannot engage the parking brake, as this is not designed to stop a moving vehicle. All it will do is put the vehicle's transmission into Neutral, so you will actually eliminate any braking force that the car transmission and regenerative braking system can provide.

 

First of all, I never said it WAS a fault with the car, nor can I be sure that the OP's experience and mine were the same, even though the braking experience was similar.

Secondly, while you are so cavalierly telling the OP who had a dangerous scenario happen, including losing steering, that the experience is NOT a fault with the car and to check out the owners manual, I suggest you do this yourself, as IN this very same manual you would learn that Toyota refers to the symbol in question as The SLIP INDICATOR...not a skid warning light. This light indicates in conjunction with the activation of the Vehicle Stability Control.

In my case, which again may NOT be the same as the OP's, what the Toyota Service Department told me after supposedly checking "everything", was that it is indeed the Vehicle Stability Control working "per normal" when it senses the wheels slipping.

IMO...my opinion.....if this is so? The Prius has a way overly aggressive VSC system. To "control" a skid, the system evidently overrides braking power. What you end up with? Is the brake pedal all the way to the floor, and the vehicle very orderly, and without skidding, continuing to move forward. I personally would like a little skid in that situation. The two times it has happened to me? One time resulted in a very slow rear end collision, and the second time a white knuckle swerve to avoid situation not too unlike the OP's.

I still question if this is "normal". To me there should be NO situation, with any system activated that results in the brake pedal being all the way to the floor, and seemingly no braking power available. ( No I did NOT pump the brakes).

But also like the OP, I'm getting the "We can't duplicate" the symptoms reply. It does seem to take a very specific but possible scenario for this to happen. Which means primarily you need a surface that is slick, and a need to suddenly brake.

To be honest? I'm willing to accept that it is the VSC, and simply how it works. I've also come to the conclusion that with The Prius, mild winter or otherwise- I need snow tires every winter, because evidently with The Prius traction and how it plays with the whole braking system is especially paramount, given that I think the VSC has a "flaw" in how it can react. --I very much don't like this aspect of The Prius.

Especially in the case of the OP, who evidently had a loss of braking power and steering simultaneously, I think it dangerous to post that you KNOW it's normal.

When this happened to me? Normal or not I felt I needed to have it checked out. In the case of the OP who may have an even more serious problem? I would never sight unseen suggest the operation is "normal". What the OP describes is far from any normal or safe operating standard.

I've been associated and active within Prius Chat for numerous years. I know that whenever anyone posts a "problem" as Prius owners and supporters the baseline reaction is often defensive...as in "You don't have a problem". However in this case?

I would urge the OP to continue in trying to reach a more conclusive diagnosis as to what happened, as described I think that vehicle behavior is in no way "Normal" or acceptable.

 

OP states: "I first noticed my steering wheel was very light and unresponsive..."
Question for the OP: After this incident, did the vehicle drive straight when the steering wheel is centered?

The steering linkage has a direct mechanical connection from the steering wheel to the tires. It is very unlikely that this connection disconnected and then reconnected itself. If the steering intermediate shaft disconnected from the steering column or the steering gear, it would likely remain disconnected, and be obviously loose. If the splines on either end of the shaft stripped, the shaft would remain loose.
Power steering systems (on any car) can fail and make steering heavier or lighter, but you will always be able to steer the wheels.
If the front wheels were sliding, the steering would become light, and turning the steering (and the front wheels) will not steer the car. The car would follow the slope of the road. As you state, the road tilts from right to left, and the car went from the right lane to the left lane.
Sliding can occur due to poor traction, such as when the roadway is contaminated with oil, water, sand, leaves, etc... Sliding would not necessarily be accompanied by skid marks or screeching sounds.
You state that this occurred on a bridge. Were there strong winds? A strong gust of wind may momentarily make your car light enough that it loses stability.

A few more questions for the OP: When you pressed the brake pedal and the car did not slow down as expected, how did the brake pedal feel? Did the pedal travel much farther toward the floor, was is softer or firmer than usual? Was the brake pedal high and hard?
After the incident, did the brake appear to operate normally?

 

Apologies if TheElectricME found my reply cavalier. I was suggesting checking the user manual because Mooifah just refers to "all the orange lights" lighting up without saying which lights they were. Which lights they were seems an important piece of info to me.

Thanks for the correction as to the name of the warning light. To me a slip and a skid are the same, but it is good to get our terms right.

Mooifah - I already answered your question about why the car should skid, in my post, as has PriusinParadise.

My understanding was that Mooifah was saying or assuming that it was a fault with the car - not necessarily you, TheElectricMe.

I do think that PriusinParadise makes an extremely important point about the steering, which does seem to show conclusively that whatever happened to the steering could not have been the car's fault.

Congrats too to PriusinParadise that his reply focusses on light rather than heat (metaphorically speaking), and apologies if I seemed impatient.

This is clearly a very important matter, and just as any possible dangers posed by the car and its design must be taken seriously, incidents and concerns of this nature must be considered very carefully and on the basis of all the facts, before making assumptions that it must be the car that is at fault. Such assumptions, if incorrect, can inappropriately cause anxiety in owners and problems in the resale market. In this context, it is in my view premature for Mooifah to be posting "if the manufacture told me the PRIUS is as designed in this normal driving environment I would rather not to drive the PRIUS or owned a Toyota car ever again.."

Whether or not this was a "normal driving environment" is a key question, and Mooifah is not willing to consider the possibility that there was an issue with the road surface, perhaps he could explain how the steering failed and then repaired itself?

 

I'm pretty sure that is an incorrect statement.

 

RDGrimes - I don't know what your evidence is for saying that PriusinParadise is incorrect about the steering, but I suggest you check your facts. The steering is electrically power-assisted - but entirely mechanical and directly connected between steering wheel and front wheels.
It is definitely NOT fly-by-wire like the throttle and brakes.

Here is a statement from the Toyota Newsroom, regarding a Prius steering recall some time ago:

"Customer FAQs for Toyota Prius Electric Power Steering (EPS) Pinion Shaft Nut Recall

The Electric Power Steering (EPS) system provides power assistance to reduce steering effort. It generates torque using a power steering motor and a reduction mechanism which are assembled in the steering gear box assembly."

*EDIT* You can see a diagram of the Prius steering system at the following site:
http://www.aa1car.com/library/steering_power_electric.htm
Note: I don't mean the one at the top of the page which is for a Chevy - the Prius one is further down.