MB CAN do or don't - Mercedes-Benz Forum

LinkBack Thread Tools Display Modes
post #1 of 1 (permalink) Old 08-16-2009, 10:50 PM Thread Starter
BenzWorld Elite
Date registered: Feb 2006
Vehicle: 1999 ML320
Location: Ratville
Posts: 24,029
Mentioned: 1 Post(s)
Quoted: 310 Post(s)
(Thread Starter)
MB CAN do or don't

Could this be the root cause ?
The protocol sounds like a mess.

On Mercedes cars, CAN wiring has been incorporated since 1992 to allow the sharing of information that is used for the engine, transmission, airbag, anti-lock brakes and suspension control systems. Mercedes uses a two-wire system, which allows two data streams. One handles communication for the primary modules for major components like the engine (PCM), transmission (ETC), ABS, ESP (electronic stability protection) and ASR (acceleration slip reduction), and other systems designed to protect the driver against making bad driving decisions. The other wire is used to connect accessory systems such as locks, windows, HVAC and even the audio system. That second wire also is supposed to provide a backup path if the main or primary control wire is damaged.

Since these systems were first integrated into wiring harnesses, the ability of the controllers and control units to handle more information at faster speeds has made reliability a problem. With each increase in data transfer protocol, or bandwidth, the integrity of the wiring has been the limiting factor for reliable and efficient operation.
Since the system uses digital technology, even a small hiccup will cause miscommunication, false signals and fault codes. This is probably why we see code descriptions like “implausible.” The processors (See Photo 1) are taking in and distributing information that has been interrupted or misinterpreted by another module or controller. These CAN signals are also prioritized depending on whether the information is needed by the master control module (Mercedes calls this the HFM-SFI module). Wiring and connector condition becomes a problem at even lower mileages than has been typical of Mercedes cars.
Mercedes 'CAN' Diagnostics ? Uncovering Faults Speeds The Repair Process ...

... and this important discussion continues.

mlfun is offline  
Sponsored Links

  Mercedes-Benz Forum > General Mercedes-Benz Forums > General Mercedes-Benz

Quick Reply

Register Now

In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


  • Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
    Thread Tools
    Show Printable Version Show Printable Version
    Email this Page Email this Page
    Display Modes
    Linear Mode Linear Mode

    Posting Rules  
    You may post new threads
    You may post replies
    You may not post attachments
    You may not edit your posts

    BB code is On
    Smilies are On
    [IMG] code is On
    HTML code is Off
    Trackbacks are On
    Pingbacks are On
    Refbacks are On


    Title goes here

    video goes here
    description goes here. Read Full Story
    For the best viewing experience please update your browser to Google Chrome