Component Description

PCM 

The PCM is the logic module for the four-wheel drive system. Multiple modules/system inputs are used for the four-wheel drive system to determine the percentage of torque to be transferred to the rear wheels.

Transfer Case 

The transfer case is a gearbox that attaches to the transmission. The transfer case directs power to the rear driveshaft and the Rear Drive Unit (RDU). For more information on the transfer case, Refer to: POWER TRANSFER UNIT - OVERVIEW - 2.0L EcoBoost (184kW/250PS) - MI4. Refer to: POWER TRANSFER UNIT - OVERVIEW - 2.7L EcoBoost (238kW/324PS). Refer to: POWER TRANSFER UNIT - OVERVIEW - 3.5L Duratec (212kW/278PS).

AWD Relay Module 

The AWD relay module receives the command from the PCM, and in turn supplies a PWM output to the Automatic Torque Coupling (ATC) solenoid for the requested torque to be applied.

Automatic Torque Coupling (ATC) Solenoid 

The Automatic Torque Coupling (ATC) solenoid is integral to the Rear Drive Unit (RDU), and applies clutch pressure as controlled by the AWD relay module to increase or decrease torque to the rear wheels. The Rear Drive Unit (RDU) transfers torque from the drive shaft to the rear wheels depending on the specific request from the FWD system module (PCM). The Rear Drive Unit (RDU) and Automatic Torque Coupling (ATC) solenoid are serviced in Chassis, Driveline information. Refer to: Rear Drive Axle and Differential .