Single Engine Operation; Port Engine-Only Operation; Shift Override-Emergency Procedure - Mercury Axius Manual

Section 3 - Troubleshooting

Single Engine Operation

If an engine or steering system stops functioning during use, the remaining drive is electronically limited while turning inboard.
This prevents the drives from making contact with each other, since the active drive is unable to determine the position of the
disabled drive. The boat is still operational, but maneuverability is decreased when turning toward the side that is not working.
Refer to the inboard drive angle limit in the following table. The drive is still capable of turning through its full range when
turning away from the disabled drive. Use extra caution when one of the drives is disabled.
NOTE: Joystick is not available when only one engine is operating.
Drive Limits of Engine with Module Failure
4.5L Axius Joystick Piloting for Sterndrive models
6.2L Axius Joystick Piloting for Sterndrive models
The limit may be greater than specified in the previous table depending on the propulsion personality and distance between the
drives. Single engine operation should be intentionally experienced in order to become familiar with the limits of the vessel
maneuverability.
IMPORTANT: Intentionally experiencing single engine operation for the first time should be conducted in an open area that is
not congested with obstacles or other vessel traffic.
To experience single engine operation, proceed with the following:
1. Ensure the vessel is in an open area with a calm sea.
2. Turn off the engines.
3. Start the starboard engine only.
4. Shift the starboard engine into forward gear.
5. At idle, attempt to steer the vessel, noting how it maneuvers.
6. Advance the throttle slowly while attempting to steer the vessel. Note how it maneuvers.
7. After experiencing single engine operation at various different engine RPMs, shift the starboard engine into neutral.
8. Start the port engine to continue with normal vessel operations.
IMPORTANT: There are two possible conditions that can be encountered when experiencing single engine operation with
the port engine running. 1) With the port engine running and the starboard engine key in the OFF position, you will not feel
the steering wheel end stop feedback. 2) Turning the starboard engine key to the ON position will provide steering wheel
end stop feedback.
Port Engine–Only Operation
The force feedback feature of the steering wheel is only available when the starboard key switch is in the on position. If the
starboard key switch is off or there has been damage to the starboard electrical system, the port control system monitors the
steering wheel.
If only the port side is operational, or only the port key switch is in the on position, the force feedback system will not provide
end stops for the steering wheel. In this case, the drive will turn in the direction of steering wheel rotation until the mechanical
limits of the drive are reached.
Note that joystick is not available in single‑engine operation. However, Axius features redundant trackpad systems, so Auto
Heading mode is still available during single‑engine operation.
Shift Override—Emergency Procedure
If the VesselView display shows the error message "GEAR POS DIFF" and an engine will not start or will not shift into gear,
there is a problem with the electronic shift control (ESC) system. If one drive is working, you may operate on one engine and
drive.
Using the emergency procedure to manually shift the drive disengages shift control at the helm. To avoid damage or injury,
drive cautiously when a gear is engaged manually. To stop the drive and its propeller, you must turn the key switch to the off
position.
You can disengage the shift actuator to manually shift the drive into neutral for starting and into forward gear position for
operation. Engine speed will be limited to 1000–1200 RPM while operating in emergency shift override.
To disengage the shift actuator:
1. Turn the ignition switch to the off position and engage the emergency lanyard, if equipped.
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Model
CAUTION
!
Maximum Inboard Drive Angle Limit
3.0°
3.0°
90-8M0099745 MAY 2015
eng