Test F: The Four Wheel Drive (4WD) Control Module Does Not Respond To The Scan Tool

PINPOINT TEST F: THE FOUR WHEEL DRIVE (4WD) CONTROL MODULE DOES NOT RESPOND TO THE SCAN TOOL

F1-F3:

F3-F4:

Normal Operation
The 4WD control module communicates with the scan tool through the high speed controller area network (HS-CAN). Circuits VDB04 (WH/BU) (HS-CAN +) and VDB05 (WH) (HS-CAN -) provide the network connection to the 4WD control module. The 4WD control module shares the HS-CAN with the powertrain control module (PCM), the restraints control module (RCM), the occupant classification sensor module, the instrument cluster, and the smart junction box (SJB). Voltage is supplied by circuits SBB27 (BU/RD), SBP28 (GN/RD) and CBP10 (YE/OG). Ground is supplied by circuits GD161 (BK/YE) and GD174 (BK/WH).

Possible Causes
- Fuse
- Circuit VDB04 (WH/BU) open (HS-CAN +)
- Circuit VDB05 (WH) open (HS-CAN -)
- Circuit CBP10 (YE/OG) open
- Circuit SBP28 (GN/RD) open
- Circuit SBB27 (BU/RD) open
- Circuit GD161 (BK/YE) open
- Circuit GD174 (BK/WH) open
- 4WD control module