Loss of control

chevrolet
cobalt

#1

'07 Cobalt
I read a complaint – NHTSA ID Number 10564185
total loss of control on freeway – U-turn and hit curb
service provider “said they found nothing mechanically wrong”

any idea what could cause that?


#2

Your vehicle has drive-by-wire steering.

This means a steering wheel position sensor sends a signal to the computer. The computer then takes this signal and drives an electric motor on the rack & pinion assembly which turns the front tires.

Tester


#3

I’ve only seen drive-by-wire steering on the new Lexus. On an '07 Cobalt, I’d guess either hydroplaning or power steering intermittent failure.


#4

“total loss of control on freeway – U-turn and hit curb” is way to little info to even begin to guess.

  • the driver sneezed.
  • a bee flew into the driver’s face and s/he flipped out
  • the driver was wearing fleece or knit gloves and didn’t have a reliable grip on the wheel
  • a very large gust of wind
  • the driver fell asleep
  • the driver was driving with his/her knee while combing hair
  • the driver drifted to the shoulder, panicked, and over corrected

But you might want to read this


#5

Could it be a traction problem or brake lock up on one side in the rear end. It doesn’t have to be the steering. It’s the rear end that gives a car stability. There maybe others but Nissan has a commercially available steer by wire. I don’t think it has worked it’s way down the price range too far.


#6

I’ve got electric steering on the Acura. I like it because it requires little effort to turn the wheel just like the old days. Makes long distance travel a lot easier. I wish I knew more about it though-I wouldn’t like drive by wire.


#7

If you read the complaint carefully it says the car temporarily lost all (electrical?) power, which could be caused by a faulty ignition switch, for example. If the car lost all electrical power, then the electrical power steering system would be temporarily disabled, making the car suddenly very difficult to steer.

PS: there was also a recall of the power steering assist motor on this year/model car.


#8

What was the latest GM recall for ignition shutting off after driving high speed on rough roads. Caused accidents because they couldn’t control the car with not power. Been there, but you just hang on and move to the side of the road.


#9

Don’t like electrical power steering myself and am glad my car is old enough not to have it.


#10

Wait…electric power steering or Steer-by-wire? Those are two totally different things!

Does any car actually lack mechanical linkage between steering wheel and tie-rods? If so, why? It introduces several new and scary modes of failure (loss of electricity leading to inability to steer) for no appreciable benefit.

Seems the brakes and steering, at least, shold retain mechanical actuation for safety.


#11

Sorry, I mentioned Lexus, but it’s Infinity with the steer-by-wire system. I don’t trust it and will avoid it.


#12

The car in question (2007 Cobalt) has electric power steering assist, and the electric assist motor has been the subject of a recall:

With electric power steering, there is still a mechanical link between steering wheel and wheels but it takes more force to steer if the electric assist conks out.

With the Infiniti steer-by-wire system there is an electric clutch that mechanically decouples the steering wheel from the rack and pinion, and the steering operates solely on electric motor power. But when power is lost the clutch kicks in and recouples the steering wheel mechanically to the rack and pinion.


#13

Infinity, and every other maker I’ve seen, uses an electrical assist system that provides an assist to the torque on the steering column, just like hydraulic provides a hydraulic assist to the mechanical force on the steering rack. Failure of the assist does not manifest itself as a total loss of control, simply a loss of steering assist, making the steering hard.

If any of you guys are familiar with a system that is truly “drive by wire” without a mechanical steering link to the steering wheel, I’d be interested in having you post. If these exist, I’ll want to learn more.

As to the original post, there’s way to little information to guess what the actual recall is for without doing further research. It would have been nice of the OP told us what the recall notice actually said.


#14

@meanjoe75fan "Wait…electric power steering or Steer-by-wire? Those are two totally different things!"
Exactly…there seems to be some unintended overlap.

And yes, the Infinity by Nissan is the only car that I am aware of that does it. It does have a mechanical linkage as a back up designed to re engage if the steer by wire fails.


#15

@meanjoe75fan is right. Steer-by-wire is not the same as electric steering. Electric steering assists the steering with an electric motor rather than a hydraulic system. I agree wholeheartedly that there should be a mechanical attachment for safety.

A failed system, either software or sensors, could steer it hard one-way into the wall. Steer-by-wire has vary scary failure modes. It has only been used on cars, as far as I know, at the rear. GM’s Quadra-steer was an electric steer-by-wire for the rear of trucks with VERY limited steering angles for safety’s sake.

I like electric assist steering from an efficiencies sake. I don’t mind the “feel” of it but many don’t like it.


#16

@TSM, the new Infiniti “steer by wire” goes a step further than conventional electric power steering by having a clutch that mechanically decouples the steering wheel from the rack. So in normal usage there is, in fact, no mechanical connection at all between the steering wheel and rack.

Only if electrical power is lost does the clutch kick in and reconnect the steering wheel to the rack.


#17

I don’t know if this is the place to mention this. I’m having trouble finding where to place this message, I have a 2006 Toyota Carola. Three times in the past 3 or 4 years, the car has lurched forward about 5 feet. The last time, I turned on the ignition without my foot on the break or gas peddle. Luckily I was in park and the emergency brake was on. The car went to 6RPMs. Had the car been moving, would have gone over a cliff. The Toyota dealership said they could find nothing wrong. I’m afraid to drive the car and will not sell it for fear that the new buyer will get hurt or killed (unless they are aware of what it is and can fix it). I can’t afford a new car. HELP!


#18

^
No, this is not the place to mention a situation that is totally unrelated to the subject of this thread. Instead, you need to click on the red oblong button in the upper right portion of your screen, marked “New Discussion”, and then post your own question/comment.

Once you start a new thread, you can tell us about the BRAKE, the gas PEDAL, and other information relevant to your car’s problem.


#19

I’m appalled. I lawyer reads this and seeks out accidents caused by total lack of steering. Any company this reckless deserves whatever they get.

Sorry, but this one angers me. IMHO it’s analogous to Ford actuarializing the value of a human life as a part of a design decision.


#20

TSM, unfortunately, it’s done all the time. I was watching, with interest, the development of the Airbus A380, double-decker jumbo jet. Originally, they planned to pack over 800 people into that plane. But, insurance actuaries told them no more than 550 people on the plane at a time to insure it.