Ford Ecosport: Four-Wheel Drive Systems / Description and Operation - Four-Wheel Drive Systems - System Operation and Component Description

System Operation

System Diagram

Network Message Chart

  Module Network Input MessagesPCM

Spare Tire And Mismatched Tire Sizes

If the spare tire is installed, the AWD system may disable automatically and enter FWD only mode to protect driveline components. This condition may be indicated by AWD OFF message in the message center. If there is a Check AWD message in the message center from using the spare tire, this indicator should turn off after reinstalling the repaired or replaced normal road tire and cycling the ignition OFF and ON. It is recommended to reinstall the repaired or replaced road tire as soon as possible. Major dissimilar tire sizes between the front and rear axles could cause the AWD system to stop functioning and default to FWD or damage the AWD system. If this condition occurs, a DTC is set and a Check AWD message is displayed on the message center.

AWD Control And Fault Indicators

The AWD system consists of a transfer case, driveshaft, front and rear halfshafts, AWD relay module, Rear Drive Unit (RDU) with integral Active Torque Coupling (ATC) solenoid, and includes the PCM for AWD control logic. Using inputs from various module/systems, the PCM sends a command to the AWD relay module which controls the amount of torque sent to the rear wheels by sending a PWM duty cycle to the Active Torque Coupling (ATC) solenoid. AWD system faults are indicated by a driveline icon indicator in the IPC as well as the Check AWD message in the message center.

AWD Bar Code Identification

The AWD system on this vehicle is equipped with an Active Torque Coupling (ATC) solenoid to reduce the tolerance of electrical current to torque delivered to the Active Torque Coupling (ATC) solenoid. The Active Torque Coupling (ATC) solenoid has a bar code label that can be found on the bottom of the Rear Drive Unit (RDU). The PCM uses this bar code information to match the clutch characteristics of the Active Torque Coupling (ATC) solenoid with the desired output torque. If the bar code information does not match the PCM information, driveline damage or driveability concerns can occur. Therefore, if the PCM is replaced, the new PCM must be configured with the existing Active Torque Coupling (ATC) solenoid bar code information. If the Rear Drive Unit (RDU) is replaced, the existing PCM must be configured with the new Active Torque Coupling (ATC) solenoid bar code information. Also, for PCM or Rear Drive Unit (RDU) replacement the AWD Drive Cycle must be performed after the Automatic Torque Coupling Configuration.

Automatic Torque Coupling Configuration Bar Code Label

Automatic Torque Coupling Configuration

NOTICE: If the Active Torque Coupling (ATC) solenoid bar code information is not correct, Rear Drive Unit (RDU) damage or driveability concerns can occur.

NOTE: The 4-digit alpha numeric bar code is located on the label attached to the Rear Drive Unit (RDU).

1. Using a diagnostic scan tool, perform the Automatic Traction Coupling Barcode Entry procedure. This procedure is located within Powertrain, under the toolbox icon. Follow the instructions displayed on the diagnostic scan tool.

NOTE: If the PCM was not replaced, the barcode information is already populated. If the information is different it must be changed to match the label on the Rear Drive Unit (RDU).

NOTE: The diagnostic scan tool verifies the digits entered are valid and displays a message if the information is not valid.

2. Verify and if necessary, change the barcode information to match the label on the Rear Drive Unit (RDU).

3. Carry out the AWD Drive Cycle after downloading the Active Torque Coupling (ATC) solenoid bar code information to the PCM .

AWD Drive Cycle

NOTE: Always drive the vehicle in a safe manner according to driving conditions and obey all traffic laws.

1. Carry out 3 accelerations from 0-30 mph (0-48 km/h) in a straight line.

• Perform this procedure at low, medium and full accelerator pedal position.
• Verify there is no perceived front wheel slip.

2. On dry pavement, drive the vehicle at 5 mph (8 km/h) in a fully locked turn.

• Verify there is no driveline binding.

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: Transfer Case - Overview (308-07B Transfer Case - 6-Speed Automatic Transmission – 6F35, Description and Operation).

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 AWD module. The Rear Drive Unit (RDU) and Automatic Torque Coupling (ATC) solenoid are serviced in Chassis, Driveline section.
Refer to: Axle Assembly (205-02 Rear Drive Axle/Differential, Removal and Installation).