Test F: Vehicle Has No or Inadequate Torque at Rear Wheels
Pinpoint Test F: Vehicle Has No or Inadequate Torque at Rear WheelsRefer to Vehicle/Diagrams, Four-Wheel Drive System for schematic and connector information.
Normal Operation
The on-demand four wheel drive (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 controller area network (HS-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.
^ DTC P1635 Tire/Axle Out of Acceptable Range - When the 4WD control module detects incorrect input values from ABS module (due to wheel size/tire mismatch greater than 5 percent [mini-spare installed as a road wheel]), this DTC is set.
^ DTC P1824 4WD Clutch Relay Circuit Failure When the 4WD control module detects a 4WD solenoid short to ground or short to battery on the active torque coupling feedback circuit, this DTC is set. DTC P1825 4WD Clutch Relay Open Circuit When the 4WD control module detects an open on the active torque coupling command or feedback circuit, this DTC is set.
This pinpoint test is intended to diagnose the following:
^ Tire(s)/axle(s) out of range
^ Active torque coupling
^ 4WD control module
^ Power transfer unit (PTU)
^ Circuit GD126GS (BK/WH) open
^ Circuit SBP11 (BU/RD) open
^ Circuit CCF21A (VT/WH) open or short to ground
^ Circuit RCF21B (WH/VT) open or short to ground
^ Circuit A-CBP35 (YE/GY) open
F1-F2:
F2 (Continued)-F4:
F4 (Continued)-F6:
F6 (Continued)-F8:
F8 (Continued)-F9:
F10-F12:
