Module-Final Drive Control: Description
WARNING: This page is about a different car, the 2006 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
The Final Drive Control Module (FDCM) (2) is a microprocessor-based assembly, controlling a 4X4 Transfer Case and Front and Rear Electronic Limited Slip Differentials (ELSD's). Communication is via the CAN serial bus. Inputs include user selectable 4X4 modes that include 4WD Full Time (4HI), 4LO, Neutral. The logic and driver circuitry is contained in aluminum housing base and a stamped steel housing cover with an embedded heat sink See Fig 1.
The FDCM is installed inside the passenger compartment underneath the driver side of the rear seat.