You disconnected the battery, bought a second Connect NAV navigation unit, or perhaps you simply never had the code for your radio? In each of these cases, a moment after switching on the ignition, you will see a screen asking for a 4-digit code. Master Code request in Magneti Marelli navigation units is a common problem for owners of cars such as Fiat (Stilo, Panda, Croma, Bravo, Doblo), Alfa Romeo (MiTo, 147, GT, 156, 159, Brera, Spider, Giulietta) or Lancia (Ypsilon, Musa, Delta, Thesis). Unfortunately, most car audio services are unable to unlock such a unit. The barrier here is not the software itself, but the ability to solder properly and program flash memory, that is, the chips in which the data is stored. That is where the digits needed to accept the Master Code request are stored.
Magneti Marelli Master Code request – navigation unlock
When correctly connected, the navigation unit communicates with the car’s computer via the CAN bus, that is, the vehicle’s communication bus. If the chassis number is different from the one previously stored in memory, the radio will display a prompt to enter the code.
In practice, you then need to enter four digits and you can enjoy the sound again.
Procedure for reading the original radio code
In Connect NAV / Connect NAV+ navigation units, the pin for your system is stored in flash memory on the main board. If that sounds too technical, it is worth simply looking at photos of the main board.
If you are wondering what is needed to read the pin for Master Code request, you need the right setup to power up the radio outside the car, the ability to solder memory chips in TSOP packages, and a programmer that supports these memory chips. Finally, you also need to know the code-reading algorithm or have the right software. If all this seems too complicated, you can commission this service from OEMatic.
And to top it off, a few photos — for those who are curious what the main board and the unit menu look like.
Unlocked Connect Nav navigation
And what if your car is a Giulietta with a similar system? In such units, the code is stored in different chips, but there is a method for that as well. Take a look at our post code for Alfa Romeo Giulietta navigation.
