Test A: No Communication With the 4-Wheel Drive (4WD) Control Module

Pinpoint A: No Communication With The 4-Wheel Drive (4WD) Control Module

Test A1:

Test A1:

CAUTION: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use the standard multimeter probes.

Normal Operation
The 4WD control module (PCM) communicates with the diagnostic tool through the CAN communications network. If the 4WD control module (PCM) loses power, it will not be able to communicate. Check power circuit 994 (WH) for an open. If the circuit proves out; Refer to Information Bus for further diagnostics.

Possible Causes
^ Circuit 994 (WH)
^ 4-wheel drive (4WD) control module (PCM)