Just wanted to throw this out for comment or observation. I had a problem with my diesel truck causing the clock to go screwy on start up. Since I have to turn the key forward and wait for the glow plugs, my F90BT starts to boot up and then is inturrupted when I crank the engine and it reboots. This makes the clock reset to 12:00 a.m. and then have to get a GPS fix again before it will be accurate, which can take a couple of minutes. It does this every morning.
Friday, I chipped the truck with a product from DP-Tuner in hopes of better fuel mileage. One thing I noticed right away was that the engine really kicks over when cranked--starts much faster. The last couple of days, I noticed that the clock remains accurate--even though the starting procedure hasn't changed at all. Makes me wonder if the longer crank time was drawing too much current causing the AVIC to be 'starved'.
Before deciding on the F90 I looked into other brands/models. One that I can't remember the name had crash problems, but one guy found that if he ran a heavy gauge wire, directly from the battery to the constant current wire of his headunit--all problems went away. Any possibility that this could be contributing to any of the problems that some may be experiencing with erratic behavior of the AVIC F series?