Components activated in selected gears

Fig 1: Identifying Selected Gear System Function Chart

Courtesy of VOLVO CARS OF NORTH AMERICA.

Clutches: 

1. C1- Engages the input shaft with the rear planetary train (P1) ring gear.
2. C2 - Engages the input shaft with the sun gear shaft for the primary shaft planetary trains (P1, P2).
3. C3 - Engages the planetary gear carrier with the sun gear for the secondary shaft planetary gear (P3).

Brakes: 

1. B1 - Locks the sun gear shaft for the primary shaft planetary trains (P1, P2) so that it cannot rotate in any direction.
2. B2 - Locks, using F1, the sun gear shaft for the primary shaft planetary trains (P1, P2) so that it cannot rotate counter-clockwise.
3. B3- Locks the front planetary train (P2) ring gear so that it cannot rotate in any direction.
4. B4 - Locks the sun gear for the secondary shaft planetary train (P3) so that it cannot rotate in any direction.

Freewheel: 

1. F1 - Prevents the sun gear shaft for the primary shaft planetary trains (P1, P2) from rotating counter-clockwise when B2 is engaged.
2. F2 - Prevents the front planetary train (P2) ring gear from rotating counter-clockwise.
3. F3 - Prevents the sun gear for the secondary shaft planetary train (P3) from rotating clockwise.

Gear shift solenoids: 

1. S1 - Controls shifting in the transmission. Activated in 2nd and 3rd gears.
2. S2 - Controls shifting in the transmission. Activated in back-up (reverse) gear, 1st and 2nd gears.