Normal Operation
The active, on-demand 4WD system utilizes data from other systems as inputs to the 4WD control module. The 4WD control module uses the inputs to determine the appropriate duty cycle to send to the active torque coupling that delivers the desired torque to the rear wheels. Specific inputs to the 4WD control module are: throttle position output from the PCM, transmission range from the PCM, as well as brake system status and all 4 wheel speeds from the ABS module. Communication between the 4WD control module and other modules is obtained through the high speed controller area network (CAN). If other modules communicate with the diagnostic tool and the 4WD control module cannot, check the power and ground circuits to the 4WD control module before replacement of the module.
If the 4WD control module observes an over-power or under-power condition, DTCs are set and the 4WD control module may not allow 4WD operation.
The on-demand 4WD system uses data from other systems as inputs to the 4WD control module. The 4WD control module uses the inputs to determine the appropriate duty cycle to send to the active torque coupling that delivers the desired torque to the rear wheels. Specific inputs to the 4WD control module are: throttle position output from the PCM, transmission range from the PCM, brake system status and all 4 wheel speeds from the ABS module. Communication between the 4WD control module and other modules is obtained through the high speed CAN. If the 4WD control module loses communication with, or receives invalid data from any of the necessary modules, DTCs are set and the 4WD control module may not allow 4WD operation.
The on-demand 4WD system uses data from other systems as inputs to the 4WD control module. The 4WD control module uses the inputs to determine the appropriate duty cycle to send to the active torque coupling that delivers the desired torque to the rear wheels. Specific inputs to the 4WD control module are: throttle position output from the PCM, transmission range from the PCM, brake system status and all 4 wheel speeds from the ABS module. Communication between the 4WD control module and other modules is obtained through the high speed CAN. If the 4WD control module loses communication with, or receives invalid data from any of the necessary modules, DTCs are set and the 4WD control module may not allow 4WD operation.
The on-demand 4WD system uses data from other systems as inputs to the 4WD control module. The 4WD control module uses the inputs to determine the appropriate duty cycle to send to the active torque coupling that delivers the desired torque to the rear wheels. Specific inputs to the 4WD control module are: throttle position output from the PCM, transmission range from the PCM, brake system status and all 4 wheel speeds from the ABS module. Communication between the 4WD control module and other modules is obtained through the high speed CAN. If the 4WD control module loses communication with, or receives invalid data from any of the necessary modules, DTCs are set and the 4WD control module may not allow 4WD operation.
The on-demand 4WD system uses data from other systems as inputs to the 4WD control module. The 4WD control module uses the inputs to determine the appropriate duty cycle to send to the active torque coupling that delivers the desired torque to the rear wheels. If the 4WD control module loses communication with, or receives invalid data from any of the necessary modules, DTCs are set and the 4WD control module may not allow 4WD operation.
The 4WD control module communicates with the instrument cluster through the high speed CAN. The instrument cluster illuminates the 4WD indicator when as requested by the 4WD control module. Problems with either the high speed CAN or the instrument cluster can effect 4WD operation.
4WD - Illuminates continuously when the 4WD system is locked into permanent four-wheel drive due to heat protection mode. In the locked mode the vehicle resists turning and binds up when driven on dry pavement. To exit the locked mode, stop the vehicle and allow it to cool. When the 4WD indicator turns off, normal 4WD system function is restored.
4WD - Blinks continuously when the 4WD system is disabled due to its heat protection mode. To exit the disabled mode, stop the vehicle and allow it to cool. When the indicator turns off, normal 4WD system function is restored.
4WD - Blinks 3, 6, 8 or 10 times every minute when the 4WD system requires service. Use a diagnostic tool to check for DTCs. Refer to the FOUR-WHEEL DRIVE (4WD) CONTROL MODULE DIAGNOSTIC TROUBLE CODE (DTC) INDEX .
| Blinks | Cause |
|---|---|
| 3 | Cluster is not receiving the 4WD indicator message from the 4WD control module |
| 6 | Invalid throttle position data received from the PCM |
| 8 | Invalid wheel speed data received from the ABS module |
| 10 | Active torque coupling circuit fault |
4WD INDICATOR CODE DESCRIPTIONS
The vehicle is equipped with an on-demand 4WD system that is always active and requires no driver input. The system has no mode select switch. The system combines transparent all-surface operation with highly capable four-wheel drive, and is capable of handling all road conditions, including street and highway driving as well as off-road and winter operation.
The 4WD system continuously monitors vehicle conditions and automatically adjusts the torque distribution between the front and rear wheels. During normal operation, most of the torque is sent to the front wheels. If wheel slip between the front and rear wheels is detected, or if the vehicle is under heavy acceleration, the 4WD system will increase the torque to the rear wheels to prevent or control wheel slip.
The 4WD control module varies the torque sent to the rear wheels by sending a duty cycle to the active torque coupling located inside the rear axle. The 4WD control module also provides the brake system with its current clutch duty cycle and whether or not the brake system may take command of the clutch duty cycle.
The 4WD system continuously monitors vehicle conditions and automatically adjusts the torque distribution between the front and rear wheels. During normal operation, most of the torque is sent to the front wheels. If wheel slip between the front and rear wheels is detected, or if the vehicle is under heavy acceleration, the 4WD system increases the torque to the rear wheels to prevent or control wheel slip.
The 4WD control module varies the torque sent to the rear wheels by sending a duty cycle to the active torque coupling located inside the rear axle. The 4WD control module also provides the brake system with its current clutch duty cycle and whether or not the brake system may take command of the clutch duty cycle.