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Fly by wire???....huh?

This is on every CAN vehicle, every new car today has this. There are a lot of advantages to a system like that with all of the cool features a modern car has.
 
I know about Drive-By-Wire, Thanks "Veedubshafer"

But I just do not under stand the point of giving control to a computer
If the computer crashes so does the jeep ?? The mechanical linkages
was been working just fine for 100 years. After all I'm the one driving

Whats next steering and braking by wire ? Oh wait a minute,..
Traction control system works with the brakes :D
 
danny Benavidez said:
I know about Drive-By-Wire, Thanks "Veedubshafer"

But I just do not under stand the point of giving control to a computer
If the computer crashes so does the jeep ?? The mechanical linkages
was been working just fine for 100 years. After all I'm the one driving

Whats next steering and braking by wire ? Oh wait a minute,..
Traction control system works with the brakes :D
Click to expand...

Yes. Volvo has some things like this already in the works. Start saying goodbye to steering columns now before its too late. Oh, I work at a Harley Davidson dealer and the touring bikes have had throttle by wire starting in '08. Even old school H-D getting into it.
 
All the drive by wire systems I have driven feel perfectly normal. I can't help but think those of you who say you can feel a lag are just imagining it. Or what you feel is not caused by the drive by wire at all but something else. As for the question of why have it, well it simplifies things under the hood for one. Another use is it makes the cruise control, traction control, and active handling systems much more smooth by giving the computer control over the throttle. Personally I'm very impressed by how reliable and tranparent the system really is.
 
danny Benavidez said:
I know about Drive-By-Wire, Thanks "Veedubshafer"

But I just do not under stand the point of giving control to a computer
If the computer crashes so does the jeep ?? The mechanical linkages
was been working just fine for 100 years. After all I'm the one driving

Whats next steering and braking by wire ? Oh wait a minute,..
Traction control system works with the brakes :D
Click to expand...

Because if the computer "crashes" on your XJ the engine still dies.

Look, your XJ is practically drive by wire anyway, move your TPS down to the gas pedal, and install a servo on the TB and its the same setup as what a modern vehicle has.

The only thing the throttle cable does is directly control the TB position, all the other electronics still work the same.


On a modern diesel its all drive by wire, no Throttle body at all, just a TPS(or APPS as its known the CRD people) down at the pedal(also note that the KJ APPS is shared with toyotas, so its a commonly made part).

Your "mechanical linkage" hasn't controlled a cherokee engine in over 20 years, it was the electronic injection doing that, you just provided the input via a meter long cable to the electronic pickup.
 
Z06guy said:
All the drive by wire systems I have driven feel perfectly normal. I can't help but think those of you who say you can feel a lag are just imagining it. Or what you feel is not caused by the drive by wire at all but something else. As for the question of why have it, well it simplifies things under the hood for one. Another use is it makes the cruise control, traction control, and active handling systems much more smooth by giving the computer control over the throttle. Personally I'm very impressed by how reliable and tranparent the system really is.
Click to expand...

You can definitely feel the hesitation, it's not anyones imagination. I drive vehicles all day long and when you drive with and without a vehicle with a cable you can feel the lag. If you don't think about it, it is fairly transparent. We have customers return after they buy a new vehicle wondering why there is a delay on throttle response all the time. It is cool having all in one unit, But when you have a issue like the TPS go bad you get to buy a $500.00+ throttlebody, instead of a $75.00 TPS!
 
The lag is definitely not in your imagination. It gets better and better all the time but the earlier ones like my '04 GTI VR6 were pretty crappy. I have an open intake on my car. If you just tap the gas quick with your foot it makes a loud sucking sound right at first and its very noticable that its way after you actually hit the pedal. When I purchased the car new and my Dad drove it he didn't know it was TBW and and even said that the throttle seemed like it was lagging. Like I said if you think we are just imagining it we aren't. Oh, and with a manual transmission it makes a smooth shift alot harder to be had. I actually have gotten used to almost drive like I am beating the car and getting back on it earlier when shifting and it actually turns out to be a normal smooth shift instead.
 
Whats next steering and braking by wire
Click to expand...

My gf's ISF has some sort of electronic brake control. Not that anti-slip nonsense or anything, I'm pretty sure the calipers are in some way controlled by electronics. I'll do a little more research.
 
DoctorPhate said:
Not sure how you would. Its faster then the human can think.
Click to expand...

Sorry Doc, my brain must be pretty damn fast then. I used to race Top Fuel motorcycles with a good ole cable controlled throttle. I KNOW what instant throttle response feels like. It is VERY obvious on some cars, and im sure its better on others, but as I originally stated every car I have driven with it, it can be felt. It's certainly not the end of the world, and they obviously work or every car mfg. wouldn't be going that direction, but it's annoying at times.

I'll keep my cable.

~James
 
danny Benavidez said:
Why would a car maker not use a cable ? why make it harded to fix And what if the system fails?,....
Click to expand...

The original purpose of the servo throttle is for emissions. No matter how sophisticated the emissions system, when you change throttle position, you change the A/F ratio. Your foot can do it a lot faster then the computer can keep up with. In our Cherokees, whenever the computer detected a change(via the TPS) the system tripped into open-loop mode and used a fixed curve until engine speed/throttle position stabilized, the went back into closed loop. In open loop, emissions suck.
With the new systems, and a servo controlled throttle, the computer controls how fast the TB opens, and can adjust the F/A at the same time.

If the system fails, well, I hope it's got a fail safe that closes the throttle somehow. Other then that, it's just like every other sensor/elec. component on the engine.

Edit: and yes, if you're paying attention, you can feel a lag when you hit the gas in one of those things.
 
DanMan2k06 said:
I though it was only in open loop upon startup? When the o2 sensors are still warming up?
Click to expand...
Actually it's in open loop until the engine warms up, not the O2 sensor. It's also always in open loop at WOT. Any recorded sensor failure also pushes it open loop, which is a big chunck of the reason the older XJs get such crappy mileage.

I read something on the early(obd-1 and-2) systems a while back, and I was surprised how the system really works. 'Forget what the whole list was,but there are a lot of normal driving conditions where the system's in open loop.
 
The hand controls I use to drive make throttle response even more noticeable than it is using a foot pedal. The various systems do vary, and by a significant margin in my experience. The throttle response on my 93 XJ is pretty equivalent to that on my 03 Duramax, whereas the throttle on my wife's 08 Grand Caravan with the 3.8 is SLOOOOOOOOOOooooooow! I hate driving that thing, not just because it's a minivan, and not just because it's a relatively gutless engine, but because there's almost time for a nap between the time you move the throttle and the time the engine responds.
If you're not comfortable with drive-by-wire, just wait until those on-board computers start responding to signals from someone other than you!!! :patriot:
 
I think FordGuy is doing a better job proving my point that I did

FordGuy said:
They fail all of the time, I bet we do 2-3 a week!
&
TPS go bad you get to buy a $500.00+ throttlebody, instead of a $75.00 TPS!
Click to expand...

Thats about $1500 per week plus labor :shhh:
Like i'll trying to say computers fail than what ?
 
What Rd said:
If you're not comfortable with drive-by-wire, just wait until those on-board computers start responding to signals from someone other than you!!! :patriot:
Click to expand...
Funny that came up. GM can shut down ANY Onstar equipped vehicle for the police.(even if there's no active account)
 
danny Benavidez said:
Do not forget our next meeting is coming up soon !
www.StopTheComputersFromTakingOver.com :laugh:
Click to expand...

Cute, but stupid. :dunce:
The computers aren't any threat - it's your benevolent socialist President. Just think how much safer and more fuel efficient you'll be when the Anointed One starts taking care of all those dangerous decisions for you - like where to go, when and how fast, even whether you Really need to take that trip in your "personal" vehicle or should use the much more environmentally friendly and socially egalitarian mass transit.
I can't wait!!!!!!
 
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