1999 "EE" 90, 115 FFI, 150, 175 V4, V6 FFI Outboards Service Manual, P/N 787024, Page 60Get this manual
If sensor values are below the limits, or the sensor or its circuit malfunctions, the ECU will store service code, and turn on the "CHECK ENGINE" lightThe engine will not go into S.L.OW Shift Interrupt SwitchV6 Only: The shift interrupt switch is in contact with the shift leverThe switch is normally open; when the button is depressed (by excessive shift loads), the switch is closed and completes ground circuitThe ECU then shuts off fuel and spark to three cylinders (No.2, 4, and 6) for six revolutions (approximately seconds) to momentarily reduce drivetrain loads and ease shifting, then automatically restores normal engine operationThe signal threshold is 2500 RPM; the shift interrupt function will not work above itThe switch must be released to its normally open position before the interrupt circuit can be actuated againThe ECU provides voltage signal to the shift interrupt switch; another wire connects the switch to powerhead groundIf the switch or its circuit fails, the ECU will store service code and turn on the "CHECK ENGINE" light