Pinpoint Test 3: 4X4 Control Module Received No/Invalid Data From PCM

PINPOINT TEST 3: 4X4 CONTROL MODULE RECEIVED NO/INVALID DATA FROM PCM

Normal Operation

The on-demand four wheel drive (4WD) 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 the rear axle) that delivers the desired torque to the rear wheels. Specific inputs to the 4X4 control module are: accelerator pedal 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 4X4 control module and other modules is obtained through the high-speed controller area network (HS-CAN). 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 4WD operation.

- DTC U0415 (Invalid Data Received from Anti-Lock Brake System (ABS) Control Module) - sets when the 4X4 control module receives invalid HS-CAN bus data or invalid wheel speed(s) from the ABS module for more than 5 seconds.

Possible Causes
- ABS module

Diagnostic Procedure

WARNING:When directed to drive the vehicle as part of this test, drive the vehicle on a hard surface in an area without traffic to prevent a crash. Failure to follow these instructions may result in personal injury.
NOTE:Carry out Steps 1-10 outlined in Inspection and Verification prior to carrying out this test. See Initial Inspection and Diagnostic Overview.

Step 1-Step 2: