W210, 1997 E320 Basic Electronics Questions
 

I've been through the archives and have found bits and pieces of information with respects to the various electronic control systems on a W210.

Is there a site or could we start a thread that would give a BASIC overview of the electronic control systems?

I often see abbreviations that I do not understand, and even when I do figure out what the abbreviation stands for, I do not know what that particular electronic control unit is responsible for or does.

Thanks for any and all replies!

No basic electronics left on that car! Plenty of the communication is now over CAN, rather than using separate wires as was common in the past.

But I do like playing with the N-22.

Thanks!! What major components are on the Common Area Network and what do they basically do?

Actually Bigdaddy, your car isn't quite as complicated as you think. 1997 was the last year MB vehicles DIDN'T use the extensive CAN network in use today. Of course, engine management, traction control, transmission, etc. use high speed CAN, but the interior accessories don't involve much CAN at all.

A simple rule of thumb is that if an MB has a standard type blade key/ignition switch, it doesn't have interior CAN (as we know it). If it has a "smart-key"/electronic ignition switch, it's got interior CAN. Old ML's are a different story, but that's a topic for another thread.

Hey there ILUVMILS!!!

My car has the black flip-out key with the circuit board and proximity chip inside the key housing. I know this because I dropped the key one day, it came apart and I tried to start the car with just the actual metal key part and the car wouldn't start!....Is this type of key the "smart key" type that you mentioned?

Also, if you have a moment could you post the major components that are on the CAN amd what they do?

Thanks a lot for you reply, I'm an ex ASE certified mechanic that's been an electronics technician for 7 years now and most of the technological advances in the auto industry are new to me. I'm attempting to catch up, at least on a basic level......I have great "old school" automotive troubleshooting skills and I was hoping that my electronics background would help me to better understand the newer MB technologies........I from the days of removing trigger points from 450sels and cleaning them, so forgive me for my gross ignorance! :)

Bigdaddybenz-
The simplest and quickest way to get familiar with all of the nomenclature and CAN diagrams is to purchase a subscription at ALLDATA.com for your car. You get a year's worth of access to their data base for about 25 dollars.
You'll find "Operation and Description" sections for most of the systems and subsystems for your car. The diagrams use the MB abbreviations you want and will tell you that N22 is the climate control head in the dash.
If you look up Powertrain Management, I think you'll find a complete description of how your key/alarm/immobilizer work...
You can also buy into the MB on line database (expensive if you just want to browse) or find a WIS manual.
You'll be amazed how much "stuff" talks to each other. You'll also be surprised where some of it is located in the car.
Hope this helps.

Your car is the last of the "low tech" MB's, at least as far as CAN is concerned. The 1998 model year was the turning point. If you're a DIY'er, consider yourself lucky. Diagnosing CAN issues without an SDS is next to impossible.

It's impossible to describe the CAN system details in just a few paragraphs, but I'll try to hit a few of the highlights. One of the most important things to remember is that there's no DIRECT electrical connection between the switch and consumer. Nearly every interior switch on a modern MB sends a signal, requesting a particular task, to the nearest control module. The control module then sends out the request(turn on rear dome light, open L/R window, etc.)over the CAN databus. The control module responsible for this function receives the request and carries out the task. The glove box light, cigarette lighter, and visor lights are the only directly switched consumers left. Everything else is electronically controlled.

There are also several different CAN applications on MB vehicles. The engine CAN (CAN C)runs at 500 kbps. The interior CAN (CAN B) is much slower at 83.3 kbps. Models R230 and W211 use a "discreet" CAN (SBC CAN) in their braking systems. Discreet CAN is also used in central locking/drive authorization systems. Some components which use CAN are the Door Control Modules, Seat Control Modules, Lower Control Panel, Upper Control Panel, Overhead Control Panel, Front SAM(s), Rear SAM, Instrument Cluster, Electronic Ignition Switch, Steering Column Module, Climate Control Module, etc.