I've read tons of posts in the archives about the maintenance mode of the various BMW headunits. You know, this is where you set the speed sensitive volume (GAL). On the newer headunits like the Z3 in-dash, one of the settings is AF ON. I'm dying to know what this does. Has anyone figured it out yet?
Thanks,
-cliff

The AF function refers to the "Automatic Frequency tuning" function and when this is turned on the radio looks for the strongest signal. So as the car moves out of range from one transmitter the radio will search for a stronger signal and it will change the frequency when a stronger signal becomes available . the benefits are that you dont need to keep re tuning the radio on a journey.when the AF is switched off the radio will stay on the frequency that was set regardless of signal strength. This function is only avialable on FM .