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Pinpoint Test 4: Four Wheel Drive (4WD) Control Module Received No/Invalid Data From ABS Module

PINPOINT TEST 4: FOUR WHEEL DRIVE (4WD) CONTROL MODULE RECEIVED NO/INVALID DATA FROM ABS MODULE

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 pulse-width modulated (PWM) command 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 U0415 Invalid Data Received from ABS - When the 4WD control module receives invalid HS-CAN bus messaged wheel speed(s) from the ABS module for more than 30 seconds from the PCM, this DTC is set.

Possible Causes
^ ABS module

Diagnostic Procedure

Caution
^ This test must be carried out on a hard surface in a vacant area without traffic.


Note
^ Conduct Steps 1-10 outlined in Inspection and Verification prior to performing this test. See FOUR WHEEL DRIVE (4WD) SYSTEMS INSPECTION AND VERIFICATION. Four Wheel Drive (4WD) Systems Inspection and Verification

Step 1-Step 2: