Normal Operation

WARNING: This page is about a different car, the 2006 Mercury Mariner and 2006 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

The PCM communicates with the diagnostic tool through the high speed controller area network (CAN), circuits 1908 (WH) and 1909 (BK). If one of the bus wires becomes shorted to ground or voltage, communications can continue at a reduced level. The PCM and instrument cluster share network termination responsibilities with the use of a split termination resistor in each module. If either of these termination resistors is lost, network communication is not possible. Check circuits 1908 (WH) and 1909 (BK) between the PCM C175b and the data link connector (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 one of the high speed CAN circuits, damage to the DLC C251, damage to the PCM C175b, or a problem in an in-line connector.