Prior to disconnecting the battery, is there any way to retrieve the radio code if you don't have the card or owners manual from previous owner?

 

Not really...unless someone wrote the radio code on top of the radio housing in which event you have to pull the radio to verify.
Go to the dealer...for free...they will get you the code.....usually past work orders from dealers have the radio code on the work order.
If you are not the original owner...the dealer will still have a record...they need the VIN, etc.
If you have a 1432 radio...it's a 4 digit code...

 

OK, Thanks! I'll try the dealership and see if they can give it to me.

 

https://mbworld.org/forums/e-class-w...adio-code.html