Found this:
Will try it tomorrow:
Start the engine and keep the doors and boot closed so that you don't have a warning message displayed
Keep the odometer reset button pressed until the Board Computer screen changes (around 10 seconds)
Release the button when the screen changes. You'll see a nice menu with numbered options. To scroll through the options just press the odometer button
Go to option number 4 (UNLOCK) and then press the odometer button for a couple of seconds to enter the menu for this option. It will ask for the unlock code.
Don't panic! You have the code, it's the sum of your car's VIN number's last 5 digits. For example, if the last 5 digits on the VIN of your car are 12345, the code is 15.
To enter the code, you have to press the odometer button for as many times as the sum indicates. For the example we showed you at step 5, you'll have to press the button 15 times.
After inserting the code, press the odometer reset button for a couple of seconds to go to the previous menu, revealing the secret menu.
That's it! Now you can do all sorts of things with your hidden menu: check oil temps, coolant temps, MPG, etc. Enjoy!
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