Driver's Control Center Differential System: General

The Driver's Control Center Differential (DCCD) system consists of the sensors and switches such as steering angle sensor, yaw rate and lateral G sensor, or stop light switch, the planetary gear type center differential (with built-in the LSD clutch), and the DCCD control module.

The center differential of double pinion gear type planetary unit distributes the engine torque to the front wheels and rear wheels at the torque ratio of 41:59.

(In the actual planetary gear unit, 3 sets of double pinion gears are used. But the figure shows only 2 sets of double pinion gears for simplification.)

Fig 1: Identifying Driver's Control Center Differential System Components

Courtesy of SUBARU OF AMERICA, INC.

• The LSD mechanism improves the initial steering operation response further by combining and using the conventional solenoid clutch LSD mechanism and the torque sensing mechanical LSD mechanism.

  When the solenoid clutch LSD is in the free condition, the mechanical LSD mechanism performs the differential control of 0 - 30%. The other 30 - 100% differential control can be performed by activating the solenoid clutch LSD.

  Fig 2: Sectional View Of Driver's Control Center Differential System

  Courtesy of SUBARU OF AMERICA, INC.
• The drivability and stability during cornering were made compatible by using the yaw rate and lateral G sensor and the newly adapted steering angle sensor. With this, the quick steering characteristics and the improvement of cornering ability are achieved, and the tight cornering symptom may also be decreased.
• In manual mode, the engagement power of solenoid clutch LSD can be adjusted within the range of 30 to 100%.
• When a malfunction occurs in the system, the fail-safe control may be performed that releases the solenoid clutch LSD so as to maintain safe conditions. At this time, the Subaru Select Monitor can be used for the system diagnosis.