Pinpoint Test A: No Communication With The 4x4 Module (PCM): Notes
WARNING: This page is about a different car, the 2004 Mercury Mountaineer and 2004 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
Normal Operation
In order for the 4x4 module (PCM) to communicate with the scan tool, the operating voltage required to supply the 4WD module is in a range between 9 and 16 volts. Voltage is supplied by circuit 729 (RD/WH) and circuit 994 (WH).
Possible Causes
- CAN communication
- scan tool
- battery junction box (BJB) fuse 18 (20A)
- central junction box (CJB) fuse 24 (15A)
- power supply:
- circuit 729 (RD/WH)
- circuit 994 (WH)
- ground circuits:
- circuit 570a (BK/WH)
- circuit 570b (BK/WH)
- 570c (BK/WH)
- 4x4 module (PCM)
- charging system