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Carsoft 7.4 Multiplexer Diagnostic Tool for MB

280052 Views 376 Replies 72 Participants Last post by  bluerooster
Kajtek1 - I am moving this discussion to a new thread from here ... since the "W210 Aux Water Pump" sticky was getting off topic. Sorry, I'm the one that digressed.

I and Texholdem provided the following links for the Carsoft Multiplexer kit...

$106.80 - MB Carsoft 7.4 Interface Multiplexed MCU Interface for Mercedes Benz - OBD/OBD2 Car Diag. Tools

MB Carsoft 7.4 Multiplexer Diagnostic Tool for sale at

I have the first kit. The two kits seem identical except the first one includes a nice carrying case. The second link doesn't explicitly say that a copy of the software is included. My kit came with Carsoft 7.4 software. Software installation was a bit kludgy but it works.

I am running the software on a spare IBM Thinkpad T40 laptop with Windows XP. This laptop doesn't have a serial port that is need for the Carsoft kit. I use a SIIG Single-Serial PC Card that I got off ebay for 10 bucks.

There is not much documentation for the software. There's just a quick overview under the help menu. The usage is mostly self evident.

Some nice features in the software:

1. Live data analysis for ME (including O2 sensors) and EGS. But there's no graphing capability like the one found on ELMSCAN. In any case, I don't see myself driving around with the carsoft setup; you can't close the hood with the 38 pin connector plugged in. I might get the ELMSCAN some day just for live engine analytics and graphing (the ELMSCAN plugs into the OBD-II connector; you can plug it in and drive the car. But you shouldn't look at the laptop screen while driving :) Have someone else drive the car while you observe the live data).

2. Ability to do "coding" for ME, Airbag, and D2B and to perform "adaptation erase" for EGS and ME (I haven't tested these features.) I recall reading on another thread here that someone coded a new transmission control unit with carsoft. I don't see that feature in the software.

3. Ability to reset service interval

4. The software includes a glossary of all the MB acronyms such as PSE, EGS, etc. This was a big help for me. Also, as part of the live Airco analysis, it lists what all the 20 or so climate control diagnostic readings stand for.

If nothing else, Carsoft kit gives me peace of mind.
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The carsoft software can cost $500-$2500 according to other threads. Beware with downloaded software because of virus.

I ordered an ELM327 for $30 but it has not arrived yet. It won't do some of the things like Carsoft but I need the live data.

CAN-BUS Auto Scanner, ELM327 USB CAN-BUS Auto Scanner
  • Features: ELM327 is the latest PC-based scan tool. It supports all OBD-II protocols and is dispatched with a number of compatible programs. The processor is an ELM327. The output protocol (connection to laptop) is USB.
  • Processor: ELM327.
  • OBD-II Software for ELM327 is a free program that allows you to use your PC and a hardware interface to get the information from your car's computer.
  • The program is very user-friendly, and easy to learn. It is also very easy to install: simply extract the files into a folder on your computer's hard drive, and you're ready to go. To uninstall the program, simply delete the entire contents of the folder where the program resides.
  • The software supports two platforms - DOS and Windows.
  • The program lets you perform the following operations: Read diagnostic trouble codes, both generic and manufacturer-specific, and display their meaning (over 3000 generic code definitions in the database).
  • Clear trouble codes and turn off the MIL ("Check Engine" light)
  • Display current sensor data, including:
  • Engine RPM
  • Calculated Load Value
  • Coolant Temperature
  • Fuel System Status
  • Vehicle Speed
  • Short Term Fuel Trim
  • Long Term Fuel Trim
  • Intake Manifold Pressure
  • Timing Advance
  • Intake Air Temperature
  • Air Flow Rate
  • Absolute Throttle Position
  • Oxygen sensor voltages / associated short term fuel trims
  • Fuel System status
  • Fuel Pressure
  • Many others...
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The carsoft software can cost $500-$2500 according to other threads. Beware with downloaded software because of virus.

I ordered an ELM327 for $30 but it has not arrived yet.
Mbvis - I agree that the genuine carsoft software costs $500-$2500. What's included with the $100 kits is a cracked version of the software. Because you never know what's included with such software, I am running it on an old laptop that I've solely dedicated to running carsoft.

As I said, the ELM software is good for what it can do including live engine analytics. But it can't access myriad of other control modules on an MB because it doesn't connect to the 38 pin connector. It doesn't allow you to code and erase adaptations. I have carsoft for now and will get ELM for live analytics someday.

I will post screenshots from carsoft in a few days so everyone can see the extent of the functionality.
If you follow to this page Wholesale hot sale MB Carsoft 7.4 Multiplexer for free shipping
you will find a picture showing a disc, but also one feedback telling it doesn't work.
Sounds like high risk transaction.
Last weekend my seven pass. 4matic wagon was the bus for a bunch going skiing. Amongst the 7 of us there were 3 with CELs on. That's partly why I drove. Anyhow I mentioned I'd bought the diagnostic system (Carsoft) and a chorus went up to get their cars "read." So now I'm wishing I'd bought a generic obdII or something that would do friends brand X cars too. This ELM 327 sounds like it might work. Anyone have experience with it on Hondas and Subarus?
I have one of the "offshore" versions of the Carsoft hw and sw.
1) Sw installation is a bit cludgy and need to follow the instructions specifically, but then it does work
2) It does seem to do what carsoft claims to do
3) No real documentation beyond that, your on your own to determine what the data means.
4) it does allow you to erase error codes that you can't erase with an OBDII scanner.

5) BUT BEWARE, Here is the biggest issue. the only surefire way to make sure it will work is to have a laptop with a real true serial port. E.G. a VERY old laptop. put my daughters old laptop to the task and it works fine.

Use of a laptop with a USB-RS232 or PCMCIA- RS323 or Cardbus-RS232 May or May NOT communicate with the SW. It's really hit or misss. It may appear to work, then give bogus data, it may give a communication error, it may really work, or it may work for a while or a test or two before it gives a communication error.

BTW this above issue may occur with the real SW as well.
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Does anyone know if those work on vista?
No, XP only - best compatibilty on IBM T22/T30 preferred with serial port to avoid conflicts
Does anyone know if those work on vista?
When installing/running programs on Vista, you can choose to do it in 95, XP, ME, or 2000 mode. Right mouse button click on the program icon pops up a menu, choose <property> then <compatibility>.
But beware with "cheap" software. People warned about some virus named BANCO included with "cheap" carsoft 7.4
Vista is fine if it's up to date, but it's not XP. Some programs only work correctly on the real XP.

I very much prefer Vista to XP. Now, I've never used less than the "Professional" version of each, and more often use the server versions (2003 and 2008).
No, XP only - best compatibilty on IBM T22/T30 preferred with serial port to avoid conflicts
Another option is the Dell D620/630. It's a much newer platform, so it should be more easily available.
thank you all, I see what I can tinker about :thumbsup: .
WOW. the price went from $77 to $99 overnight.
What did you guys do?
WOW. the price went from $77 to $99 overnight.
What did you guys do?
How about $43.28 free shipping?

Wholesale MB Carsoft 7.4 Interface diagnostic tool
Not clear to me whether this is a genuine multiplexer, or just a simple interface?

Feedback, please!

I decided I can risk $43 and ordered the product. I guess in about a week, or 2 I will be asking how da heck make that thing working.
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