DTC 1601 and 1602 not clearing after battery replacement in 2010 599

Hello,

I have a 2010 Ferrari 599 GTB with 6500 miles on it. I had this car converted to a gated 6-speed by EAG. The car has been running perfectly for several months. Last week, the battery was dead (7 v). After replacing the battery, many error messages and lights appeared in the instrument cluster.

There is a thread here somewhere that lists steps to do after a battery replacement. Disconnect the battery, wait until the car is cold, reconnect the battery (using the Torx battery shutoff switch), then follow a pattern of key turns and running the car. I tried that, it didn't work.

I have an Autel and a FiCom. Both have the latest software updates. I was able to clear almost all of the codes with a few exceptions.

1. Instrument Display - 1601/Node Missing
2. Body Control Unit - 1602/B-Can Line Error (bus off)

The airbag light and message appear as well as a yellow triangle that says "Electrical System Failure".

The car starts and drives normally, as far as I can tell.

Two nights ago, I took the car out and drove it. Ten minutes into the drive, all of the error messages cleared and the car looked completely normal. Five minutes after that, they came back on.

Sam the programmer (works wtih Trevor) also tried to help me solve it and was unable to.

One other thing to note is that when reading the codes with the FiCom, the errors show as "Stored". When using the AuTel, the codes show as "Active".

I have tried going into each module and clearing the codes that way, no change.

Any ideas?
Thanks!