Ford Focus 2004 Owner's Manual page 74

Controls and features
6. After the coding process is
completed remove the key from the
ignition switch. Wait five seconds
for the system to be activated.
If coding is not completed
correctly, the indicator light flashes
after the ignition is switched on
with the newly coded key and the
engine will not start.
Repeat the coding process after
waiting 20 seconds with the
ignition switched on (position II).
If a key is lost, it is
imperative to erase and
recode the remaining keys.
Consult your Ford Dealer if you
now have only one valid key.
72
Coding erasure
With two keys coded for your
vehicle you can make all the other
coded keys unusable, e.g. after loss:
Complete each of the following
steps within five seconds.
Carry out the first four steps under
Key coding, then continue as
follows:
1. Insert the second key in the
ignition switch and turn to
position II.
2. Remove the key from the
ignition switch.
3. Insert the first key in the
ignition switch, turn to position II
and hold. The control light flashes
for five seconds.
4. If the ignition is switched off
during these five seconds, the
erasure process is terminated and
no key is erased.
5. If the erasure process is
completed, all the other keys, apart
from the two used for erasure, can
no longer be used unless recoded.
Additional keys can now be coded.