I really appreciate the offer and the great info. I may take you up on that shortly, as I must resolve this. What you said about the update possibly failing is probably exactly why the Autologic folks advise against their customers updating these units. It makes sense, how could a shop justify the risk of bricking a customers erratically functioning unit? They could end up buying the customer a new unit. But if it is a HW problem, I'd certainly want to repair it rather than replace the whole unit it if it's not too difficult. But while taking apart computers, laptops, or swapping a nav screen on my E53 is pretty much in my wheelhouse, if it's a matter of micro soldering, that's something I would rather have done by an expert.

However, I did check the battery out this morning, and it is at least slightly suspect. So I think I need to address that first.

With a VOM, after the car sitting all night, I got 12.35 V at the battery, and from my understanding, it should be more like 12.75 V. Not good.

I have a little Solar digital batter tester. That showed 12.49 V, but when set for the 900 CCA the current AGM battery is supposed to have, it showed 997 CCA. It also showed the green LED indicating the battery was good, but significantly, it also the yellow LED indicating that it's weak and needs a charge. So this afternoon, I'm going to put it on the battery charger for a few hours, and see the result. If the CCC starts functioning normally, I guess that means it's time for a battery, as there's no reason it should be weak...the car has been in constant use.

I really have no idea if the current battery was properly coded to the car, so it may not be getting the proper charge either. I could be wrong on this, but as far as I know, the only way to remedy a situation with where a battery was installed at some point in the past without being coded, is to start fresh with a new battery, and immediately code it...which I can certainly handle with a friend's Autologic.

Let me know, i will send you all info that I have.
There is another problem with Autologic and the devices on the MOST(optical) bus. The ICOM and OPPS, original BMW tools, are programming them thru a special MOST interface. Many people have tried to update the MOST devices with Winkfp, thru a standart OBD interface, I dont know of any attempt that was succeeded. It also takes enormously long time. I dont know if Autologic has a a MOST interface, but my guess is no.

Thanks!

Autologic does now have a fibre optic interface. I think it's an added cost option, so I gather not all Autologic users have this, but that's what we used to do the drivetrain updates on my car. Even with the fibre optic connection, some of the updates took a really long time, so if you used just the obdii interface, you'd be there forever. We used a Snap-on battery charger hooked to the car that has a special option for providing stable voltage to the car throughout the process.

Well, I replaced the battery, (new Bosch battery, properly coded), and I'm still having problems with the Nav/radio. It seems to take 2-3 minutes to start up after the car's been sitting for a while. I get the disclaimer message, but clicking the iDrive knob does nothing. Eventually the unit wakes up and performs normally.

Once the unit is up and running, if I shut off the car, and immediately restart the car, the nav/radio comes on immediately.

Well two days after the new battery, the CCC seems to be back to normal. It was not good at first, but got gradually better to the point where it is now working as it should. I guess it took some time for the car to stabilize the voltage level and adjust to the new battery. You would think it's a living thing adjusting to a transplanted organ.

So I would.conclude your nav radio is very sensitive to the voltage? Not until battery was adapted to did your radio work well again.

Good to hear it is Ok now. Hopefully for long.

Thanks again for your assistance and advice.

On to next BMW project....replacing the NAV screen on the SO's 325xi work beater, (waiting for the two special tools 651110 to arrive from ECS...)