Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

Register Log in
  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

The ignition switch? 7

Status
Not open for further replies.
enginesrus

enginesrus

Mechanical
Aug 30, 2003
1,016
Does anyone know what year and what manufacture started to use a computer to control the ignition switch. I'm sure every auto now has this feature, and the start stop technology is proof it exists.
I am particularly curious if a 2009 Honda CR-V has this type of ignition switch. Because if it does then it will need a manual E-Stop button installed.
 
Replies continue below

Recommended for you

Sort by date Sort by votes
What will the e-stop "stop"? Technically, the computer controls the various engine functions, such as the fuel pump, the ignition timing, the throttle, and the starter solenoid, among others. Which are you looking to cut off? Selecting neutral is the best bet in terms of allowing everything else to continue to function, but I'm not sure what you want to have happen.
 
Upvote 0 Downvote
Every OE that I know has used the ECM to command starter functionality for 20+ years, the switch just sends the driver request to the ECM.

E-stops allow drivers to kill vehicle power during runaways, fires, etc. On a test car they’re usually the big red mushroom in the ugly lil box velcroed or otherwise poorly fastened to the top of the dash. On a racecar they’re usually installed with a bit more pride.
 
Upvote 0 Downvote
I do not know the details of that particular vehicle - you would have to obtain the factory service manual and dig through wiring diagrams to see where the circuits for the ignition switch go. But ...

If any vehicle in that generation ever had a factory trim level with pushbutton start, or if there was ever a factory option for remote-start via the key fob, or if it ever had a factory-equipped immobiliser-type alarm system, you can be certain that all engine starting and running functions are commanded through the ECU, even on the trim-level versions that don't have those features.
 
Upvote 0 Downvote
The E-Stop would be in series with the power supply to the coils, I'm guessing they are controlled by the ECU grounding them? Too many cases of unintended acceleration, all fully computerized vehicles need an E-Stop button. So do all Max 8 aircraft, since all sources tell me the plane still has control cables. If ignition is commanded by the computer system that means the only control on some older vehicles that the driver has is the steering wheel.
 
Upvote 0 Downvote
Too many? Most every case of unintended acceleration is due to the driver pushing the accelerator pedal. One case was a pedal trapped by a floor mat; the same car with the same mat stuck the same way was stopped a day or so before by using the brakes.

E-stops only work when the user isn't panicked - panic appears to be the case for every driver in every unintended acceleration accident.

Anyway - it's easier to pull power from the fuel pump.
 
Upvote 0 Downvote
On most cars with push button start pressing and holding the start button for 3 seconds stops the engine. This should be mentioned in the manual.


Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376
 
Upvote 0 Downvote
Upvote 0 Downvote

Maybe some acceleration problems are caused by incapable drivers. But with fly by wire and total computerized control of every system in a vehicle now, it is possible to have a runaway. Many things can cause that with electronic systems. Most newer vehicles have full on board diagnostics by radio capabilities, works similar to onstar and probably not well known, that opens them up to hacking and remote control.
In a runaway condition, how can you turn it off if the computer controls everything? The accelerator or throttle, the brakes ABS, now the electronic steering, the full electrically actuated valve body with no mechanical linkage to the manual valve or park pawl, the parking brake, and of course the ignition switch system. In such cases your basically in for the ride in an autonomously controlled vehicle, that you think your in control of via video game joy sticks of sorts.

Hand full of reports?, like everyone with some car problem is going to go on line to report it. Gosh most of them don't even get reported to the manufacture, check the above link.

Some new learning in this.

Fuel pump power I thought of that, but then it can have a small run on time, maybe just use a DPST and pull both.

I use to have a vehicle that did an unintended acceleration deal, it had a little linkage problem, I'd just turn off the ignition switch if it wouldn't clear right away, but then some of us are not the panic types.
 
Upvote 0 Downvote
enginesrus said:
The E-Stop would be in series with the power supply to the coils, I'm guessing they are controlled by the ECU grounding them? Too many cases of unintended acceleration, all fully computerized vehicles need an E-Stop button. So do all Max 8 aircraft, since all sources tell me the plane still has control cables. . .
Click to expand...
What a great idea - E-Stops in aircraft. Think of the lives that could be saved!

je suis charlie
 
Upvote 0 Downvote
The E-Stop in an aircraft is to get all automation out of the loop. So it does not interfere with a pilot trying to save his plane that a computer has hijacked. Not to E-Stop the engines.
If those Max 8's had that hundreds of people would be alive.
 
Upvote 0 Downvote
If those Max 8's had that hundreds of people would be alive.
Click to expand...

Not necessarily; the pilots would still have needed to know what the MCAS system was doing; moreover, EVERYTHING in the controls have some level of automation, even if it's not FBW. An FBW Airbus would fall out of the sky if you E-stopped its automation system since all controls would die.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
 
Upvote 0 Downvote
That's the puzzle for Ethiopian. The entire MCAS operation was detailed in the Lion Air Preliminary report that was issued on or about the same day Ethiopian took possession of their accident airplane; also at the same time the FAA Emergency AD and the new FCOM pages from Boeing were issued to Ethiopian. Yet, 5 months later when their crash happened, neither pilot had been through any training on the matter. It's been 21 months since the typical final report issue date for Ethiopia to do so.
 
Upvote 0 Downvote
The whole idea of an E-stop in the plane would be to get rid of MCAS and any other computer trying to hijack the plane. Yeah Airbus and all the other full flyby wire tubular coffins, at first there were tons of fatality's with them. Any place that electronics has full authority over control there is a chance of some problem. 5G is concerning many pilots.
 
Upvote 0 Downvote
The whole idea of an E-stop in the plane would be to get rid of MCAS and any other computer trying to hijack the plane.
Click to expand...

That's a remedy possibly worse than the disease, in most cases. If the designers could get to the point of identifying all possible cases of "hijack" the MCAS incident wouldn't have occurred in the first place. There are almost always unintended consequences for any drastic actions like this. MCAS is a teensy, teensy, part of millions of lines of code. Adding an E-stop means likely years of regression and safety testing, and they cheated on the testing as it is.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
 
Upvote 0 Downvote
Status
Not open for further replies.

Similar threads

M
  • Locked
  • News
Missing: The first Aston Martin
Replies
0
Views
759
MintJulep
M
Finnn
  • Locked
  • Question
How would I determine the overturni 1
Replies
2
Views
711
gruntguru
gruntguru
Ben L.
  • Locked
  • Question
What is the purpose of the serration on these lug nuts?
Replies
5
Views
393
GregLocock
GregLocock
Rafa.tapia04
  • Locked
  • Question
wich is the best design software? 1
Replies
14
Views
583
3DDave
3DDave
BrentG
  • Locked
  • Question
Is welding behind the last axle ok? 3
Replies
9
Views
640
BrianPetersen
BrianPetersen

Part and Inventory Search

Sponsor

Back
Top Bottom