Volvo FM Handbook page 263

252 I-Shift
2 Inactivate TCS (see "Driver's Manual")
3 Choose driving program P/P+
4 Move the gear shift lever to the M position, gear
1, or the 1st reverse gear
5 Carefully press and release the accelerator pedal
with a smooth pumping action
2. Heavy starts
When stuck with a heavy load on a hill or soft surface:
1 Choose driving program P/P+ or HD
2 Select starting gear 1
3 Completely depress the accelerator pedal
4 Keep the accelerator pedal depressed even if the
warning for overloaded clutch appears
Extra torque from the engine is provided to help drive
away.
The function should be used already at the first attempt
to start, if it is an extra heavy start, as most torque is
obtained with a cold clutch.
3. Jerk starting
(Only for driving program P+)
If the truck has got stuck, it can be jerked loose by
using extra engine torque obtained during a short time.
The engine is set to a somewhat higher engine speed
and then the engine speed is reduced by using the
clutch, which helps to give extra torque during a short
time. The function can be used if the truck has e.g. got
stuck in deep clay.
1 Choose driving program P+
2 Move the gear shift lever to the A or M position,
gear 1, or to R
3 Keep the minus button pressed in
4 Completely depress the accelerator pedal (the
engine speed will rise to 1300 rpm)
5 Release the minus button, the clutch is engaged
Warning!
Starting in too high a gear strains
the clutch a lot and can increase
the risk for clutch breakdown.