Normal Operation

The All-Wheel Drive (AWD) system uses data from other systems as inputs to the 4X4 control module. The 4X4 control module uses the inputs to determine the appropriate duty cycle to send to the Active Torque Coupling (ATC) solenoid (part of rear axle) that delivers the desired torque to the rear wheels. If the 4X4 control module loses communication with, or receives invalid data from any of the necessary modules, DTCs are set and the 4X4 control module may not allow Four-Wheel Drive (4WD) operation.

• DTC P1824 4-Wheel Drive Clutch Relay Circuit Failure - When the 4X4 control module detects a short to ground on the ATC solenoid feedback circuit, this DTC is set.
• DTC P1825 4-Wheel Drive Clutch Relay Open Circuit - When the 4X4 control module detects an open or short to ground on the ATC solenoid command or feedback circuit for more than 2 seconds, this DTC is set.

This pinpoint test is intended to diagnose the following: 

• Tire/axle out of range
• Wiring, terminals or connectors
• ATC solenoid (part of rear axle)
• 4X4 control module
• Power Transfer Unit (PTU)