GM Ignition Switch Defect Culpability 3

[Anil Ghimire]

Who is to blame for loss of life because of GM Ignition Switch Defect: Engineers or the company?

 

[BrianPetersen]

... unless "engine failure" was due to key-off, in which case, then what do you do?

Now that everything is electronically controlled, the thing to do is keep safety systems including power steering awake after key-off until wheel speed sensors report zero speed.

I am convinced that someone will find a way to file a lawsuit no matter what you do. Every time you think you have made something idiot-proof, someone comes up with a better idiot. (Every time you think you have made something lawyer-proof, someone comes up with a better lawyer ...)

 

[CWB1]

Boost is typically <2x multiplier, not a 10x+ multiplier. That might mean somebody has to lift and use their foot rather than just their toe, but regardless, if you're losing control then you do what you have to. With modern materials and modern (read: large) disc brakes tho most econoboxes today feel like racecars after losing power compared to my classic clunkers' non-powered drums.

 

[waross]

I believe modern brakes still use engine vacuum to boost pressure, although I'm sure there's infinitely more electronic bits between the master cylinder and caliper.

Most of my vehicles use hydraulically powered electric brakes.
My 2001 GMC pickup has a hydraulic accumulator for the brakes. It gives between 1 1/2 and 2 1/2 stops.

Boost is typically <2x multiplier, not a 10x+ multiplier.

What on earth have you been driving?
Contrast one or two fingers with both arms working hard to make minor direction changes. In the first days of power assisted steering, the power unit was added to a conventional steering ratio.
Now with full power steering the ratio is much higher.




Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[GregLocock]

Turns lock to lock in the old days were 4.5 or so,now, with heavier cars and big fat tires and geometry that is not optimised for steering wheel torque, 1.5 turns. On the move typical assistance levels are of the same order as the steering wheel torque, but there is a lot of shape to those curves, and at Park basically the sky is the limit - about 10 Nm. I have't tried key off while moving to see what happens to the brakes, perhaps on an empty highway I'll give it a go.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[BrianPetersen]

Tried it in my car at low speed last night (while pulling up to the end of my driveway, no traffic around or obstacles to avoid, etc). 2015 Fiat, ordinary keyed ignition switch, manual transmission, has electric power steering. I switched the key off with the clutch pressed in at about 15 - 20 km/h while coming to a stop.

Engine stops right away. Lights and instruments are switched with the ignition, those go off right away. Power steering stays active with the key off until the speed drops to somewhere near walking speed, then it goes off and stays off. Power brakes are vacuum servo and those remain power assisted due to the stored vacuum, as is normal with power brakes. Steering doesn't lock until you take the key out. I don't know what happens with the ABS, although I suspect that given that the vehicle knows it's moving even though the key is off, those probably stay operational while it's moving just like the power steering does. I obviously don't know what happens to the airbag system.

 

[MacGyverS2000]

The wife's old Saturn would randomly lose its keys to the floor... while in motion. I stopped questioning what might happen and got rid of it... for another piece of crap (Nissan Cube, which I've droned on about in threads past).

Dan - Owner

http://www.Hi-TecDesigns.com

 

[CWB1]

What on earth have you been driving?
Contrast one or two fingers with both arms working hard to make minor direction changes. In the first days of power assisted steering, the power unit was added to a conventional steering ratio.
Now with full power steering the ratio is much higher.

My daily the last year has been my wife's old Chevy Cobalt, literally the vehicle that started this entire recall. Unfortunately I am able to attest that there is little difference between powered and nonpowered steering and braking on that model as the chime on ours has been intermittent since new, the LED screen is rather small and dim, and consequently we have run it out of gas a half dozen or so times in almost 200k. If the loss of power steering and/or braking was a significant issue on this model as several of you fellas are describing then I'd likely be dead as I've run it empty several times in dense Detroit traffic at 80+, not to mention the many local engineers driving/breaking (typically cobbled) test cars in similar circumstances. I'd wager most modern vehicles without power steering or brakes still steer and stop better than most of the 50'ish year old pickups I've restored. Reality happens, engines stop, and most folks deal with it accordingly.