Active Components In Different Gear Positions

Clutches:
C1: Connects the input shaft with the rear planetary gear train's (P1) ring gears.
C2: Connects the input shah with the common sun wheel of planetary gear trains P1 and P2.
C3: Connects the lower planetary gear train's (P3) planet carrier with the sun wheel.

Brakes:
B1: Locks the primary shaft's sun wheel to prevent it from rotating.
B2: Prevents the primary shaft's sun wheel from rotating anti-clockwise.
B3: Locks the primary shaft's ring gear.
B4: Locks the lower planetary gear train's (P3) sun wheel.

Freewheel:
F1: Prevents the front planetary gear train's (P2) ring gear from rotating counter-clockwise when B2 is applied.
F2: Prevents the front planetary gear train's (P2) ring gear from rotating counter-clockwise.
F3: Prevents the lower planetary gear train's (P3) sun wheel from rotating clockwise.