Quoted from another thread, how to access hidden menu, actual revs is under menu item 7.2:
Originally Posted by savage.ulm1
The reset button for the partial km will be named from now : 'T'.
1: insert the ig.key into the slot pushing in the meantime the T button. You enter into the secret menu. It will appear a code like for example ZB12345.
2: You have to add all the numbers you see. Example:12345 = 1+2+3+4+5 = 15.
Remember this sum.
3: Push 'T' several times untill you will see the menu n.19. Wait for about 2 seconds.
4: it will appear the sentence : "lock on" and after other 2 sec. "code 00".
ush the "T" button how many times like the sum you got before (in this case : 15).Ok now you have entered into the secret menu.
Now the menu will go automatically to menu number 01.
6: push the "T" button for example 7 times and wait for some seconds untill you will enter into the sub-menu 7.1- 7,2 etc . In this area you will see the water temperature...For the complete list read the precedent post.
Note: when the car is not with the engine running, make a test with the menu n. 2....Very spectacular....
Reference to old thread: