Fiat PSA Remote Marelli vs Delphi

What is the difference between Fiat after-market remote?  Looks no difference on the PCB.

Fiat Marreli And Delphi Remote 1

Left: Marelli,  Right Delphi


Marelli and Delphi are the 2 brand models, of FIAT brand BSI (intelligent service box).

Xxxxx25 is Marelli, xxxxxx2Y where Y is for letter its Delphi

The difference from delphi and Marelli is only the pin used for the push buttons (resistors allocations for buttons).

Fiat Marreli And Delphi Remote 2

there is a difference, look closer. There are 2 types of remote, the difference is in an integrated circuit on the PCB: 8 pin IC for cars with Marelli BSI and 10 pin IC for cars with Delphi BSI, they are not interchangeable.

Fiat Marreli And Delphi Remote 3

With this information, it should help you a lot.

Fiat Marreli And Delphi Remote 5

Tips to program Fiat remote:

Chinese remotes incl. Keydiy and Xhorse keys are not good for Mareli Fiat. Best is to buy 2nd hand original, change PCF and enjoy fully working key without any issues. Or use silca key.

So use original/slica keys for Fiat Marelli type and Chinese key for Delphi system.

Pre-coding a Fiat/Alfa/Lancia remote it’s a thing since years, but you need the right tools to do it.
You have to read Immo data (and Pincode), and from that you can precode a simply PCF7936 only for start the car, or you can precode a remote key with PCF7946, if it’s not precoded or it’s not the right type of remote for that car, the remote will never works.

This Precoding can be done only with AVDI, Autel IM508/IM608, TMPro, SmartPRO, ZedFull,  also OBDStar and Lonsdor are pretty good and other diagnostics of this level. No remote can be precoded with clone tools or low level diagnostic tools. These remotes can be reset and reused on another car only swapping the PCF7946 with a new virgin one.
You can also order the key from Dealer, in this case they will arrive already blade-cutted and also pre-coded for your car’s BSI, only need OBD learning.