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Pinpoint Test 4: Four-Wheel Drive (4WD) Control Module Does Not Respond to the Diagnostic Tool

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

Step 1:




Step 2-Step 4:




Chart 1:




Chart 2:




Normal Operation
The 4WD control module communicates with the scan tool through the high speed controller area net-work (HS-CAN). Circuits (W/L) (HS-CAN +) and (W) (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 (L/R), (G/R) and (Y/O). Ground is supplied by circuits (B/Y) and (B/W).

Possible Causes
- Battery junction box (BJB) fuse 27 (20 A)
- Smart junction box (SJB) fuse 10 (10 A)
- Smart junction box (SJB) fuse 28 (15 A)
- Circuit (W/L) open (HS-CAN +)
- Circuit (W) open (HS-CAN -)
- Circuit (Y/O) open
- Circuit (G/R) open
- Circuit (L/R) open
- Circuit (B/Y) open
- Circuit (B/W) open
- 4WD control module

CAUTION: Use the correct probe adaptor(s) when making measurements. Failure to use the correct probe adaptor(s) may damage the connector.