Volvo 2006 V70 Operation And Care Manual page 59

L (Low gears)
The transmission is locked in gears 1 and 2 when the selector is in this position.
NOTE:
Gears 4, 3, or L can be used if you are driving in a mountainous area, towing a trailer or to increase engine braking
effect.
The transmission has a built-in limiter designed to help prevent excessive engine speeds (high rpm) when gears 4, 3
or L are selected.
pg. 95 Automatic transmission AW5
Automatic transmission - shift gate positions
The gear selector can be moved freely between N and D.
Depressing the button on the front of the gear selector knob enables you to move the gear selector to positions P, R, N,
D, 4, 3 and L.
W Winter/Wet driving mode - enhanced vehicle traction
Mode W will only function if the gear selector is in the (D)rive position.
Press the button at the base of the gear selector to engage/disengage this driving mode (see illustration).
An LED in the button will light up to indicate that W is engaged and this will also be displayed in the instrument
panel (see page 27).
This mode may be selected for starting/moving off on slippery roads.
NOTE: R-models are not equipped with this button.