Davicho is correct. It's basically giving you two digits. It will start blinking quickly. Count how many times. It will pause shortly and start blinking quickly again. Count the quick blinks again. You'll be looking for a code like "three" "five", or 35.
There's usually a clearly long delay before the cycle starts over, but I have actually seen some cars pause the same amount of time when it resets the count, as it does when it pauses between digits. The way you tell which comes first in that case is to observe that you can't have the same number twice in the table of outcomes.
