Quote:
Originally Posted by DiamondGirl
It's actually for a paper I have to write about an article I found in a newspaper regarding the new 2010 Camaro. I have to relate it to computers somehow though.
Any information you have on the ECM would be fantastic. How it works, what it does, what it controls, anything!
It looks like I have to put in a call to my Grandpa to find out who to talk to at GM about the ECM...
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Ooooohhhh, well, that's easy, I can tell you what they all do, nothing about the specifics though (and your Grandpa would have to be in direct contact with the software engineering team for Holden AND GM to get real specifics on the exact ECM).
As far as the purpose of ECMs, they all basically perform the same functions, whether you are talking about a Chevy Cobalt, Chevy Camaro, or Ferrari 360 Modena, or a Kennworth Semi Truck: they monitor and make adjustments for all the vitals of the engine (hence the initials: Engine Control Module). Each company or manufacturer might have a different name for them, but they all do the same thing.
A little history first: cars didn't always have ECMs. Not untill the late 1970's with the advent of more sophisticated fuel injection, emission controls, and fuel economy concerns. Back before then, everything on the engine was just a carburetor, a distributor with points and plugs, and that was about it. That's how fuel was delivered and the engine kept it's timing right.
Today, engines have sensors all over like you would not believe, and I couldn't even tell you everything in a few paragraphs. There's crankshaft position sensors, throttle position sensors, mass air flow sensors, temp sensors, various emission sensors, and of course the fuel injection and fuel pump operation. Modern cars have also done away with the throttle cable that connects the gas pedal to the throttle body, so you also have electronic controls for the throttle.
Brakes and transmission too. ABS, traction control, stability control. Some cars even have yaw control. If you have a fancy automatic with paddle shifters on the steering wheel, you have lots of sensors in that as well that your ECM monitors.
All of that stuff is monitored by the ECM. The ECM is pretty much exactly like the motherboard on your home PC. Only on a car, it monitors everything the engine, transmission, and brakes are doing. They operate like a motherboard, where it is powered by the 12 volts and ground that is your car's electrical system, and they will have a 5 volt supply for the microprocessors, some high frequency oscillators for clock and memory, and look exactly like a video card or network card in your computer, only it might be a bit bigger physically (smaller than a PC motherboard though).
If you look under the hood of a modern car, usually by the master high current fuse/relay box, you will see a harness of up to hundreds of wires, all in a big, thick loom, that feeds into the firewall. That's where the ECM is located, usually somewhere under the dash by the glovebox or under a floorboard kick panel. Although I do see more and more cars with the ECM right under the hood, by the engine, easilly located (you will still see lots and lots of wires going to it).
The ECM what throws the check engine lights and trips other codes in your OBD (on board diagnostics), which is that hand held device that looks like a giant calculator that the mechanic plugs in under your dash board. When he plugs it in, he can then read the code to find what the problem is with the car, and that will tell you which sensor or part is bad and needs to be replaced.
Every car has a list of computer codes that correlate to a specific sensor or part. These codes are listed in the technical service manual for the specific car (and I do not think GM has printed this manual for the Camaro yet).
All of this makes engines run more efficiently, smoother, more reliable, more power, better performance, lower emissions, and better fuel economy. The ECM is really what makes modern high tech cars possible. Without it, you'd have no ABS, an incredibly complex fuel injection system (ask old timers how fuel injection worked on a '57 Bell Air), and your V6 Camaro would not have the possibility of getting 304 hp and 29 MPG highway!
The downside of all this cool technology? If your ECM goes bad (and they don't very often but I have seen them go bad), your car won't start, and they can be $1,000 for a new one.
Hope this info helps you!