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Buying MB Star

There are plenty of diagnostic solutions out there but why not spend a bit more and have what smart use in their garages?

Modification Details

What Is MB Star?

It's the common name for the set of tools used by Mercedes and Smart to perform all diagnostics and coding.

It consists of a laptop, various pieces of software, several cables and a multiplexer.

What Can MB Star Do?

You can code keys, activate paddles, activate auto, activate cruise control, turn off all the error lights, read out
all of the error codes, set the clutch, check all systems, actuate everything on the car etc. The list is enormous.

How Much Is MB Star?

Due to the varying prices, I won't put a figure here as it'll be wrong next week. Read the rest of the page and
at the base of this page you'll see a link to who I bought mine from. Click the link and have a look at the prices.

What Do I Actually Need To Buy?

You need a laptop (ideally a Dell D630), a hard drive suitable for the latop with the MB Star
software and you'll need the multiplexer which plugs in between the laptop and the car.

If you have a 450, 451 or Roadster and have no intention of buying a 453, you are probably best off buying 2011
or 2012 software and a C3 multiplexer. Being wired instead of wireless makes it all a lot less complicated.

If you have a 453 you will have to have a C4 multiplexer. (Double check to make sure it has the UDS protocol).
The minimum date for the software is 2015 but I would recommend getting the newest version you can.

What Software Is Used?

Xentry DAS - Diagnosis Assistance System. This is the main diagnostics software.
WIS - Workshop Information System. This shows you how things are fixed.
EPC - Electronic Parts Catalogue. Lists out all of the part numbers for each car.

They are all handy to have and generally come as 1 package from the seller.

What Is A Multiplexer?

A multiplexer (or mux) is a device that can take several input signals and forward them all down a single line.
Essentially, it takes data received through several pins and transfers it down 1 line
into the laptop for the software to view. There are a few main types of multiplexer

C3 Multiplexer

This was the original design from Mercedes. It's a rubber capped aluminium brick with a connector at each end.
200mm x 130mm x 85mm and weighing in at 1.3 kilograms*. It has 1 LED on the front panel.

This multiplexer was created to communicate with the CAN bus cars that were being brought out. 
It could also communicate with K-line diagnostic cars like the smart 450 fortwo and Roadster.

C4 Multiplexer
a.k.a. SDconnect

The update was called the C4. An aluminium extrusion with a hard plastic surround and 2 connectors at 1 end.
215mm x 155mm x 50mm and weighing in at 1 kilogram*.

It has 4 LEDs, an LCD and 4 buttons. This multiplexer is wireless between the laptop and the multiplexer.

This replaced the C3 multiplexer due to an addition of a third diagnostic protocol.
It still covered K-line and CAN bus but now it also covered the new UDS protocol.

UDS is what is used in the smart 453 fortwo and forfour.

*Actual size and weight may vary slightly depending on the manufacturer.

Alternative C4 Multiplexer

Before Mercedes even came out with the official C4 multiplexer, a Chinese company decided to make
their own and attempt to sell it as an update. Steer well clear of this type. They are very unreliable.

Essentially, it is a C3 multiplexer, made as small as possible using the cheapest parts available.
They were a massive bodge up and they would fail all the time. Don't buy this type.

C5 Multiplexer
a.k.a. Xentry Connect

This is the newest multiplexer from Mercedes.

As of July 2016, clones of this unit are now available although this type is not required for the smart.
It is recommended that you don't get this version as it may not work at all on your smart.

I don't know how this differs from the C4 device but it is required for the new Merc hybrid (W222).

C6 Multiplexer
a.k.a. VCI

The C6 is an updated C5 multiplexer that supports the new DoIP protocol. (Diagnostics over Internet Protocol).
No smart uses this protocol so there is no point getting this multiplexer.

a.k.a. VCX C6

The VXDiag is a multipurpose multiplexer that can be programmed to connect to many car makes.
The VCX C6 comes pre-programmed to emulate the C6 Multiplexer.
It really is not any cheaper than buying a C4 Multiplexer.
There is no good reason for a smart owner to buy this over a C4.

Original Multiplexer Or Chinese Clone?

I hate to be the messenger of bad news but you aren't buying an official multiplexer for less than about £7,000.
So it's a no-brainer to get a Chinese clone multiplexer from a reputable company for less than 1/10th of the prce.


The software you get will normally be preinstalled onto a laptop or hard drive for you to install into your own laptop.
Preinstalled is a lot easier than doing it yourself and will save you 2 or 3 hours of installing and messing around.
You will get cracked versions of all of the software that you require. Some companies will also add other
software on there too like the TAN code calculator.

Software Installation - The Easy Way

What is easier than getting someone else to do it?

When I bought my 1st and HDD with the Xentry/DAS software on, I noticed a file on the desktop called Team Viewer.
I quick Google search showed me that, with the right details, someone else could control your laptop.

I assumed that the reseller did this for a reason so I left my laptop on and connected online and sent the
Team Viewer details to the reseller, asking them if they could activate the software. Next day, it was done!

This was from MBStarShop (link at the bottom of the page) but it's worth asking 1st. Just to be sure.
I suspect it's a service that any good reseller would offer so again, it's worth asking 1st.


The original MB Star setup uses an unknown Toshiba touchscreen tablet or the newer Panasonic CF-D1 tablet.
The CF-D1 is very expensive so not worth considering. You could buy 30-40 compatible laptops for the same price.

Can I Use Any Laptop?

You can but you really shouldn't. I don't advise it for simplicity sake.

The MB Star software was tweaked to work with 1 specific touchscreen tablet. When loaded onto other laptops,
it wouldn't function properly. Wouldn't connect to the car, kept crashing and didn't do what it was supposed to.
This was mainly down to the MB Star drivers controlling the hardware in the computer.

Over time, hundreds of laptops were tested for compatibility but only 2 laptops were found to work correctly.

Dell Latttude D630
IBM Thinkpad T30

The IBM T30 has a smaller screen, slower processor and was launched in 2002.
The Dell D630 has a larger screen, faster processor and was launched in 2007.

As you can imagine, the Dell D630 is the better of the 2 to go for. It's also easier to find as they aren't as old.

If you really want to use your own laptop, you can get the MB Star software on an external hard drive and run it
all through a virtual machine. This is a terrible way to do it, full of problems and I really suggest you don't bother.

The Dell D630 can be bought in working condition for around £50. I paid less than £100 for
these 2 including postage. The orange top is just vinyl to cover up the scratches on the lid.

It makes more sense to source your own laptop instead of buying it in a kit from a Chinese seller.
You'll pay more for the laptop, you'll pay more postage and you'll pay more import duty.

However, if you buy the laptop from the supplier, it will all arrive ready to use.
If you fit a hard drive to a laptop you bought separately, the software needs some setting up.
This involves collecting numbers and contacting the supplier so they can give you codes to enter.

The Dell Latitude D630 came in 2 subtle variations but they both work as an MB Star laptop.
The difference can be seen in the touchpad button layout.

450 Fortwo

Get a C3 multiplexer and the earliest version of the software that you can find.
Early versions had more options and was less restrictive when it comes to coding.
If you can get software before 2010, that'd be great.

451 Fortwo

Get a C3 multiplexer for reliability or a C4 multiplexer if you really want wireless.
MB Star software between 2010 to 2012 seems less restrictive but all MB Star software will work.

452 Roadster

Get a C3 multiplexer and the earliest version of the software that you can find.
Early versions had more options and was less restrictive when it comes to coding.
If you can get software before 2010, that'd be great.

453 Fortwo & Forfour

Get a C4 multiplexer and make sure it supports UDS (I'd imagine all the clones do now).
Get the most up-to-date MB Star software that you can.

454 Forfour

Get a C3 multiplexer for reliability or a C4 multiplexer if you really want wireless.
Software version doesn't really matter on this model as there's not many programming opportunities.

Where Can I Buy These From?

There are countless shops online and 10 times more sellers on Aliexpress who will sell you these items.
However, it's always nice to have a company recommended that someone has experience with.

These are the people I bought my C4 and HDD from.

I'm sure they aren't the cheapest but they did answer all of my emails in 24 hours and my order
only took 7 working days to arrive. Their orders can be tracked online so you know where it is.
They seemed happy to connect tomy laptop and register all of the software for me.

And this is who I bought a full touchscreen setup from.

Delivery took about 2 weeks as they had a supply issue and they forgot to install the touch screen driver
but they admitted that before I received it and sent me the link to the driver. It was a 2 minute job.

Because I bought a full system, it was already registered and functioning.
I don't know if they would connect to your laptop and register the software if you just bought an HDD.

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