MP3022 Transfer Case - Operation

OPERATION

ACTIVE TRANSFER CASE CONTROLS

Controls for the MP3022 transfer case active clutch (torque biasing device) are located in the Final Drive Control Module (FDCM) and communicated on the Controller Area Network (CAN) C bus. The FDCM monitors multiple vehicle sensors to anticipate conditions which may result in wheel slip or reduced performance and preemptively adjusts torque split to front and rear axles as needed. The FDCM also compares wheel speeds at the front and rear axles to detect wheel slippage. A complete vehicle dynamics model, or algorithm, calculates slip at each tire for given vehicle-operating conditions. When wheel slip is detected, pressure applied to the transfer case clutch pack can be increased or decreased to apply increased torque to the axle with higher traction.

TRANSFER CASE MODES

The transfer case operates in active full-time four-wheel drive (4WD AUTO) unless the driver chooses 4WD Low, 2WD or Neutral.

ELECTRIC SHIFT MECHANISM

The electronically controlled wet clutch pack uses and electric motor to actuate an internal gear train, clutch cam, and low range barrel cam. The clutch cam actuates the clutch levers that apply normal force to the multi-disc wet clutch pack. The clutch discs are alternately splined to the front and rear drive shafts. When normal force is applied to this clutch pack, torque is transferred to equalize speed differences between front and rear axles.

Transfer of torque from one wheel to the other on an axle is accomplished by using Brake Traction Control. Under the right conditions the vehicle can be driven by just one wheel.

ELECTRONIC STABILITY PROGRAM ( ESP)

Standard Electronic Stability Program (ESP) works with the four-wheel drive system to enhance traction and control through three new features: Hill Descent, Hill Start Assist and Trailer Sway Control.