Russell Ormerod

Hi there,
Would anyone here have the variant coding string for a clk500
722.9 gearbox ?

Plutoe

Hey Biff, it does not work that way----hook up your SDS and all will be clear!!

Russell Ormerod

Nothing is unclear, all I need is the variant!

Rudeney

Can you explain what you are doing? if you have replaced the conductor plate (which contains the TCU), you will need a live version of SDS to download code from MBZ and SCN code the unit.

Russell Ormerod

The original unit has no comms. So i cannot read the SCN string to transfer to the fitted unit. I have fitted a used unit, which we made virgin.

Rudeney

Even if the original conductor plate/TCU was working, you cannot read and transfer coding. In the 722.9, the TCU is now part of the Drive Authorization System and can only be coded by downloading the VIN-specific firmware from MBZ corporate via a live, licensed copy of SDS. This is called SCN (Software Calibration Number) coding.

Unless you can find a tech who is willing to use his licensed SDS to do this for you, the only way around this would be to deal with the TCU at the EEPROM level. There are two possibilities there. One is that you physically transfer the the EEPROM from the old TCU to the new one. This requires the skills to solder the tiny surface-mounted IC and also knowing how to re-seal the TCU. The other is to get a special tool that can read and program the EEPROM "in situ", via its interface. Honestly, people with those tools charge about the same as the dealer with SDS.

Russell Ormerod

Reading the scn is easy with the right tools.
Drive authorisation part is already done and personalized.
Everything can be read and changed over CAN no need to open the unit
If anyone has a clk 500 just take a screen shot of the control unit version
7g tronic on your sds. That's the screen that shows the part number and ecu version.
Many thanks

Rudeney

Russell, what tool are you using to read the SCN coding from the old TCU?

Russell Ormerod

U can see the coding in development mode, or vediamo! I used arbritus72 to reset drive authorisation.

Rudeney

Yeah, but by the time you buy Arbritus, you can just pay the dealer to SCN code it for you. Of course unless you are running your own shop and use it every day.

Russell Ormerod

That's true. Not worth it for diy! For a diy it's just easier to SCN at a dealer.
This particular clk has a slk 350 plate fitted to it. So it first needs to be flashed with the correct flash file then SCN coded. At the moment the fault codes show No CAN messages from engine controller. It starts but has no drive.

Russell Ormerod

Job Done! Flashed and coded offline!

Janne Hahling

Sorry to bring back an older thread but that variant code. What might it be for the clk500?? :-)