Principles of Operation

WARNING: This page is about a different car, the 2007 Lincoln Mark LT and 2007 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.

The all wheel drive (AWD) system is an electronic shift system that allows the operator to choose between 2 different four wheel drive (4WD) modes. The operator can switch the mode select switch (MSS) between AWD and 4H mode at any speed.

In AWD mode at rest under cruising conditions, the 4WD control module (PCM) activates the transfer case clutch at a minimum level. This allows for the small difference between the front and rear driveshaft speeds that occur normally when negotiating corners on dry pavement.

When wheel slippage occurs, the 4WD control module (PCM) will increase the torque sent to the transfer case clutch to the front wheels in order to prevent or control wheel slip.

In 4H mode the 4WD control module (PCM) signals the transfer case clutch to lock the front and rear driveshafts for maximum 4WD traction. The 4H mode is not intended for use when driving on dry or barely wet pavement. It should be used only for off-road or in severe winter driving conditions.

Feature Inputs

Mode select switch (MSS)
Wheel speeds (via CAN communication)

Feature Outputs

Transfer case clutch
Instrument cluster indicators (via CAN communication)
AWD mode (via CAN communication to PCM)