http://users.ev1.net/~sturgeon/car/focus/diag/diag.htm
The Focus ECU has a diagnostic mode which can be accessed through the instrument panel. To access it, hold in the trip reset button which turning the ignition switch to the on position. There is no need to start the engine. Continue to hold the button in until TEST is displayed on the LCD panel. You can then use the button to cycle through all the various readouts as shown below. Of course, performing this procedure will reset your trip odometer back to zero.
The photos below show the displays after each press of the trip reset button. Some of the functions are obvious while others are somewhat difficult to decipher. If anybody can provide any further information, or correct any erroneous data on this page, I'd welcome your feedback. Email me at: focuszx3@ev1.net
Sorry about the fingers in some of the photos :-)