Possible to replace 355F1 TCU without an SD-1?

I have a spare used TCU that I'd like to swap in to see if it fixes an intermittent paddle shifting issue. The workshop manual says to use an SD-1 to first read a clutch position value out of the old TCU, do the swap, then enter that value into the new TCU. How important is this? The manual also calls for "PIS" and "IO" self-calibrations but those procedures are done with the ignition key and pedals and do not mention any use of the SD-1. I'm hoping the SD-1 step is optional so that I can do the swap myself.

Incidentally, the problem I'm hoping to fix is that sometimes paddle upshift commands are ignored. This happens randomly and can persist for a few seconds or for an entire drive. I don't believe it's the paddle switch because selecting neutral (pulling both paddles) always works perfectly. It's not mechanical or hydraulic because Auto mode always works perfectly. It's not correlated with temperature, speed, rpm, or what gear the car is in, so I'm thinking electronic glitch. Three different dealerships haven't been able to figure it out or find relevant error codes. Cleaning the TCU connector contacts had no effect, so maybe the problem is in the TCU itself. This problem has been happening for several years so it would be great to finally solve it!

 

Meaning you can shift in to neutral when the upshift doesn't occur?

 

Yes, shifting into neutral always works, while in motion or not, even when upshift paddle commands are being ignored. Also I discovered that the F1 system has an emergency override to get first gear when stopped in neutral, which is done by holding the upshift paddle back for about 12 seconds. At that point there's a beep and the car shifts from N to 1 and turns on Auto mode by itself. I've had to use this trick many times after backing out of a parking space when the upshift problem happens. The delay is embarrassing if there are other cars waiting, but at least I'm not left stranded.

Anyway the ability to always select neutral and the ability to activate the override both indicate that the system is still getting signals from the upshift paddle, so that makes me think the paddle switch is not the problem.

 

Could it be the upshift switch hanging up? could be easy to check.

 

Hmm, well the switch certainly works well for neutral. There are times when I'm accelerating in say third gear, then flick the paddle repeatedly to get fourth with no response, then I try both paddles and that always gets neutral instantly. Also the Ferrari dealerships that worked on this issue checked out the switch and said it was good.

My current theory is that some circuit in the TCU is occasionally not passing through the upshift commands or is rejecting them for some reason. Since I already have a spare TCU, I'm anxious to test that theory, but I don't know if I can do the swap at home. I'll try asking the technical forum.