Normal Operation

WARNING: This page is about a different car, the 2004 Mercury Monterey and 2004 Ford Freestar. However, it is still accessible from the selected car via links, so may be relevant.

The DSM communicates with the diagnostic tool through the UART-based protocol (UBP) communications network circuit 2077 (PK/LB). If circuit 2077 (PK/LB) becomes open or shorted to ground, communications to that module will not be possible. Check circuit 2077 (PK/LB) between the DSM C341c and the 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 circuit 2077 (PK/LB), damage to the DLC C251, damage to the DSM C341 c, or a problem in the inline connectors.

The DSM fused power (overload protected) is supplied through the bussed electrical center (BEC) fuses: 10 (30A), circuit 566 (DG), and fuse 51 (10A) on circuit 1567 (RD/LB). The DSM ground circuits are circuit 1203 (BK/LB) and 1205 (BK).