Folding Seat Module
DESCRIPTION
The Folding Seat Module (FSM) (1) controls the position of the third row seats and releases the second row seat backs so that they can be folded flat using the folding seat switch bank, located on the right rear upper quarter trim panel or the third row seat switches located on the lower C-pillar trim panels. When commanded by the seat-appropriate seat back control switch, it moves the selected third row seat from the seated position to the folded position, or from the folded position to the seated position.
The second row seat backs can be released using a seat back release motor under the front of each outboard seat to fold flat by individual switches for the seats located on the right rear upper trim panel. The second row seat backs can also be released manually using the seat back release lever located next to the seat cushion on the second row seats. The seat backs can be released electronically, but can only be put back into the seated position manually as they do not have a motor on the seat for that purpose.
The FSM is attached to the left lower D-pillar using a slide and snap fit design.
OPERATION
Battery positive voltage is supplied at all time to the module through the battery positive voltage circuit and the FSM fuse located in the fuse block. The voltage is used to power up the FSM and also to apply power to the seat motors when commanded.
If the FSM detects that the key is in the START position, it will stop seat motor operation. The FSM will hold the seat in its current position until the engine crank event has completed and then continue the requested movement to completion.
The FSM uses inputs from the fold flat switches on the lower C-pillar trim panels which include the third row seat switches, right rear upper quarter trim panel seat switch bank which includes the second and third row seat selector and seat mode switches, the Controller Area Network (CAN) data bus and hall sensors located in each seat motor to determine the proper control of the third row seat motors.
The FSM receives inputs from the seat switches on the lower C-pillar trim panels or right rear upper quarter trim panel. The FSM uses the seat switch inputs to decode which seat(s) it is to control (for example, left, right or both simultaneously). The FSM uses the seat switch input to determine which seating mode is being requested for each seat. All third row switches are momentary switches that, when pressed, signal the FSM to either fold the seat back flat or raise the seat back to the seating position.
The FSM is capable of adjusting the seat(s) to the requested position when it receives the proper momentary signal from the mode-appropriate seat switch input. The possible seat modes are:
- Seated - the third row seat backrest is up and the seat cushion is in a position to allow an occupant to sit facing forward in the vehicle.
- Fold - the third row seat backrest is folded down to the seat cushion.
- Fold - the second row seat backrest is released allowing it to be folded down to the seat cushion.
The power folding system includes one motor on each seat that are obstruction sensitive to determine if the seat back is in the proper position and to stop the motor operation. The motor folds the seat back flat or into the seating position. The motors contain a hall sensor that provides inputs to the FSM for seat back position and motor speed.
The system also includes obstacle detection for safe operation. When the system detects an obstacle, the motors will stop and reverse the motion for a brief period. If the FSM detects an obstruction preventing it to back off by the required distance, the FSM will abort all seat movement. The obstacle detection feature is deactivated when the seat is (approximately 100 mm / 4 inches) before reaching the fully lowered or raised position to ensure best possible placement. Obstacle detection is also inactive during motor movements that result from diagnostic scan tool active commands.