1. Start the engine (it may work with only ignition on, I have not tried it) and make sure you have all doors and boot closed. If one door is open, it will not work.
2. Press the odometer reset button and keep it pressed until the BC screen changes (at least 10'').
3. When the screen changes, release the button. It will display a menu with numbered options. To scroll to each option you have press once the ODO resete button.
4. Go to option No. 4 UNLOCK and then press the odo reset button for a few seconds. It will enter the menu of this option and it will ask you for the unlock code.
5. The unlock code is the sum of the last 5 digits of your VIN. For example if your VIN is E123456, then the unlock code will be the number 20.
6. Enter the unlock code by pressing the odo reset button so many times required (in our example 20 times), until the number of the unlock code is displayed on the screen. If you accidentaly press the button more times than the required, worry not, just keep pressing it until it starts from 0 again.
7. Once you enter the unlock code, press again the odo rest button for a few seconds, to go to the previous menu. Now, the full unlocked menu should be displayed.
8. Scroll through all the option. Option No. 8 ''Temperature'' displays the outside temp, oil temp and coolant temp. To enter this option just press for a few seconds the odo reset button.
In general,when you are inside the hidden menu, by pressing the odo reset button once, you scroll through the options. By pressing it for a few seconds you will either enter the menu displayed or go back to the previous menu, depending on which screen you are at.