Here is a guide to renew/virgin a second-hand engine computer for Mercedes W203 C270 CDI, before replacing the old one.
ECU type: BOSCH EDC15C6 CR2.
Device used to renew: Xhorse vvdi key tool plus
Connect vvdi key tool plus with EDC15C6 ECU. You need to find pinout by yourself.
Select IMMO Programming->Benz->Select from system->Engine/Gearbox/ISM->Start programming->ECU
Save ori. ECU data
Select Renew function
Get erase password successfully
Select Renew and enter erase password
Read ECU data again.
ECU is personalized and deactivated.