BMWs completely computerized?

[blakjedi]

So today I drop my 3 series off for my first service... brake light is on, what have you...I give the service specialist the key to the car, he plugs it into the lil machine and it starts reading the cars mechanical and engine history... I am like wow ok...

The guy finds out before he ever asks me whats wrong with the car that I need new front brake pads and that the car is within its service range... Im like ok...

So I begin to start to tell him about a minor a problem I have... when ever I start the car up and hit the gas, the engine revs then the needle drops then catches I begin to move forward... at first I thought it was the cold ( I got the car in december) then I thought I needed an oil change...

Then he interrupted my thought and said "you need an software update... you been having problems going from park to drive?" I'm like yes! He said "the system knows... we'll take care of it."

I was like wow. Less than five minutes and voom I'm outta there and didnt have to tell his ass nothing. How great is that?

Because I got my car with the extended warranty (6 years, 100K, bumper to bumper) I dont have to worry about paying for anything except for damage to the vehicle (accident, etc.) glass, and tires. Everything else is covered for the life of the warranty. After owning a Volvo, and a Mercedes this is the best service I have EVER had.

Computers can be great sometimes.

 

[digitalwanderer]

Yeah, I'm seriously wanting to get a laptop and patch-in cable for my Z....just to see what the what is. 8)

 

[_xxx_]

All modern cars are like that. Every ECU ("Electronic Control Unit") has extensive diagnostics af all sensors/actuators attached to it as well as internal diagnostics. All failures are being stored in the EEPROM and can be read by the test device.

If you have all three symbols lit (brake, ABS and DSR) than it's one of the ABS sensors, I had that problem too a few weeks ago.

 

[Nappe1]

All modern cars are like that. Every ECU ("Electronic Control Unit") has extensive diagnostics af all sensors/actuators attached to it as well as internal diagnostics. All failures are being stored in the EEPROM and can be read by the test device.

If you have all three symbols lit (brake, ABS and DSR) than it's one of the ABS sensors, I had that problem too a few weeks ago.

It works like a charm until the ECU itself gets damaged. after that, you can have basically fine car with ECU that thinks everything being broken (dashboard lites like a christmas tree, when you turn key to "on" position.) and prevents you to start the car.

That is really annoying.

how to prevent having a new car like this? well, buy Hindustan or older LADA. (GAZ for our lovely neighbours ) Those won't have ECU that would go nuts.

 

[_xxx_]

It works like a charm until the ECU itself gets damaged. after that, you can have basically fine car with ECU that thinks everything being broken (dashboard lites like a christmas tree, when you turn key to "on" position.)

Which is a very reassuring thing because you'll know instantly that something's gone wrong and call the garage right away.

That Lada (LOL!) won't show you anything and you might drive another 1000 miles before maybe something really bad happens because you haven't noticed that something died...

 

[chavvdarrr]

just a thought... what happens when that "ECU" gets a virus in?
Or its OS gets BSOD ?

 

[_xxx_]

Hehe...

The ECU's usually use the OS called OSEK, which is a real-time OS for such purposes, obviously.

The only way to exchange data with the ECU is CAN-bus with a proprietary communication matrix for filtering/sorting input/output data. There are many built-in measures in order to prevent manipulations of any kind.

Surely, some devices can be hacked if you know the addresses in EEPROM. Most devices use so-called "mask" processors and these are not writable.

 

[Cartoon Corpse]

Then he interrupted my thought and said "you need an software update... you been having problems going from park to drive?" I'm like yes! He said "the system knows... we'll take care of it." Razz

pre programmed problems for them to find and fix for a price. how advanced! automated fraud! lol. kidding, but it could happen.

 

[_xxx_]

Then he interrupted my thought and said "you need an software update... you been having problems going from park to drive?" I'm like yes! He said "the system knows... we'll take care of it." Razz

pre programmed problems for them to find and fix for a price. how advanced! automated fraud! lol. kidding, but it could happen.

Sometimes we do have devices with known failures being sold to the customer. They get a silent SW-update with the next service and all is fine...

Just like releasing a game and patching it afterwards, sort of

 

[Nappe1]

It works like a charm until the ECU itself gets damaged. after that, you can have basically fine car with ECU that thinks everything being broken (dashboard lites like a christmas tree, when you turn key to "on" position.)

Which is a very reassuring thing because you'll know instantly that something's gone wrong and call the garage right away.

true, but when this happens on parking hall closing in 10 minutes, late in the evening and 50 km/h from your home, it's quite annoying. (friend of mine Citroen C5 decided to do this. Plus, the electricity system went nuts and decided that doors should not be locked. )

That Lada (LOL!) won't show you anything and you might drive another 1000 miles before maybe something really bad happens because you haven't noticed that something died...

yeah, older Ladas are made from real iron. What I mean is that I know cases where engine has been ran out of oil so long that it got totally stuck. In case of western cars, this would mean basically whole engine replacement, but with Lada, you can get it running with certain tricks. Not to mention that when temperature goes below -40 Celsius, Ladas are only ones that start.

The Off Roader version, called Lada Niva here, is truly amazing when you go to forest. It has all wheels in the corners, small wheel base and it isn't very long, so it is pertty easy to drive even in small roads. And users manual says that when using diff locks you should not drive faster than 60 km/h (last time I checked, LandCruiser and Range Rover and Land Rover stated that locks should be only used when needed and not used in speed faster than 25km/h.)

still, I rather drive with my parents -99 Yaris, than a Lada.

 

[_xxx_]

Well, western off-roaders are actually not really meant to be used off-road

It's more of a lifestyle thingy, sold to people in the cities and such. There are very few real off-roaders out there. If I had to choose one, there can be only one true winner

 

[Frank]

Many recent 4WD cars use ABS against free spinning wheels instead of locking the differentials. That's a cheap solution. Which means, that when you really need the 4WD, the cars tend to get stuck, because each wheel will independently start to spin and get braked to a stop...

And as manually locked differentials tend to generate a lot of broken axles and ruptured tires when you forget to switch them off when on a road, a (semi-) automatic way to lock them (like, for example on that Mercedes _xxx_ linked or a Subaru) is generally best.

 

[Nappe1]

Well, western off-roaders are actually not really meant to be used off-road

It's more of a lifestyle thingy, sold to people in the cities and such. There are very few real off-roaders out there. If I had to choose one, there can be only one true winner

well, that wasn't too hard to guess.
I kind of disagree that there is no real of roaders available. Range Rovers, Land Rovers, older MB G -series, MB Unimogs, Toyota LandCruiser HJ, FJ and BJ series, Hiluxes, Jeep Cherokees, Suzuki Jimnies, Even Ford Broncos can be said to be real off roaders. (though US models are usually way too big to fit in finnish forests)

It just that those aren't really advertized as much as "you wanna cruise 50 yards from home to nearest McDonalds as comfort as possible with your 15 ton SUV" -SUVs.

so, there's pletty of real adventure cars (or cars that can be turned to be off roaders quite cheap) but they aren't IN right now.

Things were quite different when Range Rover was presented in early 70's... it was powerful and quite fast car to be true off roader.

My own favorite as off roader?? umm... I really don't know. I like the sound of Rover V8 in lower rpms, but that little what I have driven off roaders, Jeep Cherokee and LandCruiser HZJ-75 have been proven to be mighty machines as well, so it would be very hard choice..

 

[London Geezer]

Computers can be great sometimes.

Heh, you wait till a virus forces your car to only go forward when you stroke the left back seat.

 

[_xxx_]

Many recent 4WD cars use ABS against free spinning wheels instead of locking the differentials. That's a cheap solution.

You mixed it up a bit. ABS prevents wheels from blocking when you brake and that's all it does.

Differential distributes the torque between the wheels according to the wheel with least slippage. What you mean is the differential lock. What it essentially does is making sure that the wheels on the respectable axle rotate with the same speed, otherwise you woudn't be able to drive straight on - it prevents the car from unwanted turns if you have one wheel on sand and one on the road, for example.

 

[Frank]

Many recent 4WD cars use ABS against free spinning wheels instead of locking the differentials. That's a cheap solution.

You mixed it up a bit. ABS prevents wheels from blocking when you brake and that's all it does.

Differential distributes the torque between the wheels according to the wheel with least slippage. What you mean is the differential lock. What it essentially does is making sure that the wheels on the respectable axle rotate with the same speed, otherwise you woudn't be able to drive straight on - it prevents the car from unwanted turns if you have one wheel on sand and one on the road, for example.

No, I mean the opposite for both points. First, if you drive on a road without differentials, or with locked ones, all wheels turn at the same speed, so you get a lot of strain on the tires and axles when you take a corner. That's why a differential gives the wheels the freedom to rotate at their own speed.

The result of that is, that if you lift the wheels from the ground and let them spin (on a normal 2WD car), one of them will rotate forward at double the normal speed, and the other will rotate backward at the same speed.

When you use differentials on a terrain where the grip of each tire can shift from "very good" to "none" and back all the time, they go back to locking the differentials, to prevent the car to stop when a single wheel loses grip, as that will start to spin at four times the normal speed, while the others stop spinning.

You can't use one of them for both terrains. But each car already has a mechanism to slow down the spin of a wheel: brakes. And there already is an electronic control on those: ABS. You could use that to prevent the wheels to spin out of control and eat all the power when they lose grip.

Unfortunately, that only works if the other wheels have a reasonable to good grip, and one of the wheels starts to spin. On ice or serious mud, all your wheels start to spin erratically, which results in your car slowly coming to a halt, and not being able to drive away again. Which would probably be just the reason why you bought a 4WD car in the first place, and not a 2WD SUV. Or even if it wasn't, you might feel ripped off anyway.

Other 4WD (or AWD) drive cars use a (semi-) automatic way to switch between both modes, thereby eliminating the above problems.

 

[_xxx_]

You can't use one of them for both terrains. But each car already has a mechanism to slow down the spin of a wheel: brakes. And there already is an electronic control on those: ABS. You could use that to prevent the wheels to spin out of control and eat all the power when they lose grip.

Unfortunately, that only works if the other wheels have a reasonable to good grip, and one of the wheels starts to spin. On ice or serious mud, all your wheels start to spin erratically, which results in your car slowly coming to a halt, and not being able to drive away again. Which would probably be just the reason why you bought a 4WD car in the first place, and not a 2WD SUV. Or even if it wasn't, you might feel ripped off anyway.

Other 4WD (or AWD) drive cars use a (semi-) automatic way to switch between both modes, thereby eliminating the above problems.

Well, I was referring to that "Unfortunately,..." bit, you'd never leave the muddy hole you're in with ABS working normally. That's why ABS is turned off the moment you engage the diff lock.

EDIT:
What you meant with preventing wheels from spinning on ice or such - that's not ABS, but ESP

 

[Frank]

Well, I was referring to that "Unfortunately,..." bit, you'd never leave the muddy hole you're in with ABS working normally. That's why ABS is turned off the moment you engage the diff lock.

EDIT:
What you meant with preventing wheels from spinning on ice or such - that's not ABS, but ESP

Ok, ESP. Sorry for the confusion, I don't mean the thing that disengages the brakes when the wheels lock. However it's called, from the moment they put electronic controls on the brakes with ABS, they started to use that for other things as well. I was talking about the application of those computer controlled brakes to reduce unwanted wheelspin, as it's much cheaper to change a program than to use expensive limited-slip differentials.

You've got lots of those acronyms that mostly mean that they use an extended program with multiple features to control those ABS brakes.

 

[_xxx_]

I was talking about the application of those computer controlled brakes to reduce unwanted wheelspin, as it's much cheaper to change a program than to use expensive limited-slip differentials.

You've got lots of those acronyms that mostly mean that they use an extended program with multiple features to control those ABS brakes.

Now you're talking about ESP, that's what it does when you drive the curves too fast Current ones can control three wheels(brakes) at once and have some very advanced algorithms.

That solution wouldn't work, since the torque would be going some 90+% on pushing against the brakes which will be engaged constantly if you're on ice, sand, mud - it's VERY slippery. And torque is what you want for forward movement

Whatever, you don't need brakes to reduce the torque. The engine control unit does it already for you much faster than any brake ever could.

Differential-lock leaves all the torque on the wheels. ESP signals every time a wheel starts slipping, engine control unit reduces the torque so that at least one wheel starts getting grip. As soon as the opposite wheel starts getting grip, you've won, since they spin simultaneously and thus will lead the car forward in a straight line more or less. It works very well actually. If you turn off the ESP, you can just go down to the metal and that might get you out of there as well. Or not.

 

[swaaye]

So what does the ECU on modern vehicles do to optimize the engine for the environment? And, how much does it influence shift patterns? This stuff is very fascinating but it's hard to figure out where to discuss it.