Main Motorcycle: 2009 Bonneville SE
Join Date: Jun 2009
Location: Asturias, Spain
Other Motorcycle: Yamaha XV1100
Extra Motorcycle: Qingqi QM200GY-BA
P1698 is a code for "Voltage control circuit malfunction". Sounds like a problem with the rectifier/regulator. If you have a multimeter measure the voltage at the battery with the engine running at a fast idle. Should be over 13 volts but no more than 14.8 or so.
I can't see what difference having a passenger makes, but can could happen is that the ECM supply relay could be slipping out of its socket. This is the small (1"x1") black box under the seat, between the barometric sensor and the tip-over cut-out switch. Its mounted on a floppy rubber mounting and might have slipped off it.
Last edited by Forchetto; 04-19-2010 at 07:53 AM.