OK, here's the summary for my Brand-new (leftover 2016) Eldorado 1400 purchased 28 May 2019
June 07, 2019 - (850 miles) flashing red triangle and "URGENT SERVICE" message on instrument cluster and bike is in limp mode
June 08, 2019 - trailered bike to dealer and home. I tell them that it's the TPS sensor. They said that it's not "throwing a code". They replaced the oil sending unit (while I waited) and changed the oil and sent me on my way. Got home and let out one quart of oil from the overfilled crankcase and then rode all around and then the light and message came back again. Still riding bike and mostly able to clear the warning triangle by selective cycling of the ignition. The issue is semi-consistent.
June 26, 2019 - returned bike to dealer, as the error is consistent now. I ask them to replace the TPS sensor.
July 31, 2019 - They pulled, inspected, cleaned and re-connected all of the electrical connections. Twice. I asked them if they replaced the TPS sensor. "No". Get bike back from dealer and ride to the 800 mile round-trip Wisconsin rally. All is well until I get home and then the error is back.
Throughout all of this, there is some amount of discussion about the Moto Guzzi diagnostic software (PADS). I offer to bring my laptop and cables and they politely decline. I get that. Customers are typically NOT trained mechanics. It turns out they either had the wrong software or no software because when they did get the PADS correctly installed, then the bike was throwing the 0155 code (TPS sensor)
August 06, 2019 - Take bike back to dealer. They perform front brake recall and attempt to diagnose the existing error. I ask if they could PLEASE replace the TPS sensor.
September 25, 2019 - Pick up bike from dealer. They replaced the TPS (demand) sensor. Finally. Have ridden the bike every day since the 25th of September and it is behaving itself.