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Tango Key Maker Function

By Richard Bunn
A Fiat 500 cannot be by OBD when no keys are available (in an all keys lost scenario).

Fiat 500 (from 2008 until 2012) – Tango Key Maker

So what is a Key Maker function? This is the terminology used by Tango which describes the function of creating a new transponder key by manipulating data which has been extracted from a vehicles ECU. This data is found from either reading the EEPROM or the Microcontroller. Therefore if you have a TANGO machine you can make new transponder keys to a huge variety of vehicles where sometimes an OBD solution is not possible.  In order to extract data from EEPROMs and MCUs you will also need an additional piece of equipment to do the actual data extraction, such as Orange5, Codex etc.

TIP: Make sure you practice your soldering BEFORE you go onto a customer’s car – don’t say I didn’t warn you!



In this case we have removed the BSI from the vehicle and used TANGO ‘Maker help’ under the help heading to show us which component we need to read on the PCB, its location and which transponder we will then use.

In summary we need to remove and extract the data from the eeprom 93C86 (using Orange5 etc), we then have the choice to program a new ID46 key using TANGO; either using a PCF7936 (standard key) or a PCF7946 (which is a remote key).


So you have successfully extracted the data from the eeprom and you have saved this file (commonly known as a bin file) to your desktop.

You then need to select which continent your vehicle is from (ASIA, EUROPE or USA).

(In this case the FIAT 500 is an Italian manufacturer therefore we select the Europe option.)


Once you have selected Europe you then move across to the ‘car model’. After selecting the car model option a drop down box of all the vehicles currently covered under the ‘Europe’ heading will appear. Select ‘Fiat’, then another drop down will automatically appear and choose ‘500’. Tango will then show you one option from where the data can be manipulated, in this case the eeprom 93C86.


Once you select the 93C86 option the following screen will appear. The next step on this screen is the ‘F icon’ (which is circled below). This is a button which allows you (once pressed) to select and open the bin file that you have created previously from reading the Fiats eeprom. TANGO will then instantly analyse the file once you have selected it (providing that the file is the correct size and has not been corrupted).


TANGO will now show you, in this case, that there are two keys already programmed to the vehicle (although lost!) and you can either overwrite the existing keys (Key 1 or Key 2 options) OR choose the Key 3 option which will just add a key to the system.

In this case we now have placed a PCF7936 (ID46) transponder into the TANGO device, selected Key 3 as our option, and then pressed the ‘W icon’ which starts the writing of the transponder process into the bin file.

ADDITIONAL INFORMATION: The ‘Key 1’ slot has a remote key already programmed which uses a PCF7946 transponder, and the ‘Key 2’ slot has a standard PCF7936 transponder already programmed.


TANGO will now open up a dialogue box which you can save with a ‘meaningful’ file name. This NEW bin file now contains the new transponders IDE and also TANGO has written that vehicles specific 6 byte secret key to the NEW transponder.


 TANGO will now prompt you to write the new file back to the eeprom (using Orange5 or Codex etc). Once the BSI is then fitted back onto the FIAT 500 the car will start with the NEW transponder key. In this case we labelled our file ‘New transponder key added 2010 Fiat 500’ – although its ’wordy’ it is descriptive; plus I would also add the registration of the vehicle to that filename in case of any future contact with the customer.


Please note that after 2012 on a FIAT 500 the eeprom was removed and the microcontroller was upgraded to a NEC MCU 70F3632. So, the transponder data is now stored inside the eeprom section of the microcontroller. At present TANGO has not released a solution for these later vehicles.

TIP: If you have time, and if your customer can wait, you can remove the BSI to look for the eeprom on the PCB. It has been reported that some Fiat 500s as late as 2014 had the older PCB with the eeprom located as previously shown.