It wont scan

Only a small number of OBD II codes are universal and mandated. Each car manufacturer is allowed to add their own. Of course Ferrari has proprietary codes and that's probably what you encountered.

 

Does your 355 have an immobilizer? If so you have to dissengage it before the scanner will work. Dissarm, turn the key to on (do not start the car) plug in scanner.

I just saw that yours is a 1998 so the above info will make it work.

 

My 96 actually has to be running before the code is read. It is one of the Ferrari quirky things.

 

+1

 

There still should have been some code visible. For example, P0700 means there is a transmission related code, but to get the specific code, like P0715 or whatever, you need a bigger tool.

 

My OBDII Scanner has worked on every car I've ever used it on.
Why it doesnt work on his F355 is crazy. I tried it with the key in the on position.
It still didnt work....

 

Maybe the ground terminal is not connected, there was a recall for that, search the forums for the fix I cant remember the link

 

You dissarmed the immobilizer first?

 

Try with the engin started. That works on my 99

 

I wonder if it matters what obd scanner your using?
Mine in an Innova 3100b.

 

Try this link you may have this issue

http://www.ferrarichat.com/forum/showpost.php?p=141824782&postcount=2

Here is the recall notice
Image Unavailable, Please Login

 

My '97 must be running too for codes to be retrieved.

 

All Ferraris prior to 2005 had a missing ground pin on the OBDII port. It was done intentionally by Ferrari, probably to get you to come to them for service . The Feds caught up with them and required them to add the ground pin so any OBDII scan tool will work. There is an open recall to add the ground pin if yours has never had the update.

Run the VIN with the local Ferrari dealer to confirm.