Volvo FM Handbook page 254

Locking gear
Example when automatic up or down-changing is not
desired can be:
• When the truck approaches a crest of a hill and one
wants to prevent an unnecessary down-change.
• On an uphill slope with a flat section.
• When driving on poor surfaces.
When automatic up or down-changing is not desired,
move the lever from position A to M. Additional
changing will not occur now and the engaged gear is
retained. To go back to the automated program and
thereby automatic gear changing again, move the gear
shift lever back to A.
The function can be used in all forward gears (1 to 12).
I-Shift 243
Note!
There is risk of over-revving when
the gear is locked.
Note!
If the vehicle is stopped with a not
permitted starting gear engaged in
the M mode, the starting gear is
automatically selected.
Caution!
Starting in too high a gear strains
the clutch a lot and can increase
the risk for clutch breakdown.
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