Reading my email at the office this AM, found a new offering from
International Rectifier. They have a new regulator mechanism that gets built
into the alternator. Similar to the ones used for years except now there is
a serial communication link between the alternator and bcm/ecu modules.
http://www.irf.com/whats-new/nr041020.html

So, in the years to come, diagnosing a bad alternator gets either more
complicated or easier depending on what tools will be available. My big beef
with the diagnostic tools that are available to us vehicle owners is that
they only will read codes (and signals on the more elaborate readers). There
is nothing that will allow you to perform actuator tests (read only and no
write control).

Oppie