Honda HSM1590i Manuel De L'utilisateur page 21

Characteristics of POWER mode:
Travel speed is automatically adjusted according to the workload so
engine power can be maintained at or near the maximum level.
Engine speed is automatically adjusted according to operating
conditions so the snow discharge distance remains constant that
have been set with the throttle control lever.
The auger is automatically raised when the snowblower is reversing.
In case the auger clutch switch is in the ON position, the auger is
automatically returned to the original position when the
snowblower begins moving forward again.
Characteristics of SELF mode:
No automatic adjustment is made. Manually adjust the engine
speed and travel speed according to the workload.
Do not turn the mode selector switch to another position while the
snowblower is moving. The electronic control unit will interpret this
as a failure; the snowblower will stop moving and the auger will stop
turning.
When the snowblower and auger stop moving/turning, move the
main shift lever to the N (neutral) position, release the drive clutch
lever once, and then squeeze it again.
Check each part to verify it is in its proper position before resuming
operation.
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