Test D: The Four-Wheel Drive (4WD) Control Module Does Not Respond To The Diagnostic Tool

PINPOINT TEST D: THE FOUR-WHEEL DRIVE (4WD) CONTROL MODULE DOES NOT RESPOND TO THE DIAGNOSTIC TOOL

D1:

D2:

Normal Operation
The 4WD control module communicates with the diagnostic tool through the high speed controller area network (CAN), circuits 1908 (WH) and 1909 (BK). If one of the bus wires becomes shorted to ground or voltage, communication can continue at a reduced level. Check circuits 1908 (WH) and 1909 (BK) between the 4WD control module C3253 and the data link connector (DLC) C251. Total resistance values must not be more than 5 ohms. If the resistance is more than 5 ohms there is an open in one of the high speed CAN circuits, damage to the DLC C251, damage to the 4WD control module C3253, or a problem in an in-line connector.

Possible Causes
- high speed CAN circuit 1908 (WH) open
- high speed CAN circuit 1909 (BK) open
- 4WD control module
- 4WD control module C3253