A vehicle occupant sensing system for detecting a condition of a vehicle seat assembly that includes at least one base and at least one upper slide member supported for movement toward and away from the base. The upper slide member is movable in response to the condition of the vehicle seat assembly. The vehicle occupant sensing system further includes at least one biasing member for biasing the upper slide member away from the base. At least one of the base and the upper slide member includes at least one retention member that is adapted for retaining the biasing member. The vehicle occupant sensing system may be employed in a vehicle seat to detect a condition of the vehicle seat.