Originally Posted by Poolside
In addition to the above, the ZFE controller constructs a VSS signal for use by the GPS. Though Rdcyclist says that possibly the VSS signal is no longer available in the harness. But there is still hope.
Even if there is no longer a VSS wire in the harness, the ZFE controller might continue to create the VSS signal, and still provide that signal to the same pin on the ZFE controller connector.
EDIT: For 2010 and later bikes without the blue/green VSS signal wire. From the schematics, the blue/green wire carrying the VSS signal comes from pin 42 on the ZFE module. So even if the blue/green wire is deleted from the harness on the 2010 and later bikes, the VSS signal might still appear on pin 42 of the ZFE controller.
Thank you for that Poolside. I'll check into that pin and see if it gives a usable VSS. I imagine the previously mentioned pull up resistor network will be needed to make it work with the Rostra.