In the MS906, under DIAGNOSIS -> CONTROL UNIT -> ENGINE, and SPECIAL FUNCTIONS, I see the option to READ VIN and WRITE VIN. Those are the only VIN options. The READ VIN works, it simply displays the VIN from either ECM. The WRITE VIN, though, doesn't actually seem to be able to write a new VIN to either ECM. When I go through the WRITE VIN option, it seems to say it will write a new VIN, but shows the existing VIN and says it is already written. When I press "OK" it does not acknowledge that it is writing or has written a new VIN. In addition to manually typing in the original VIN, I have also scanned in the original VIN while the original ECM was connected, then turned off the ignition, plugged in the used replacement ECM, turn the ignition back to ON, and then did the WRITE VIN option but it does not work.

Could anyone please advice if/how the MS906 can change the VIN on the used replacement ECM?

Thank you for your help.

I thought that the MS906 would be able to do this, but unless I am missing something, it definitely seems like this MS906 tool cannot write a VIN to an ECM that already has an existing VIN. The option to actually enter a new VIN with a used ECM only shows up when the tool is fooled into thinking the VIN is blank (by turning the ignition to off) . My guess is that it would probably write a VIN to an ECM whose VIN is empty/blank. At least that appears to be the case with a 2007 Hyundai Elantra.

Can any of the Autel tools actually write a new VIN to a used ECM that already has a VIN on it, or this basically "hit and miss" depending on your car make, model and year?