Powertrain Control Module (PCM)

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 is on the high speed CAN. The PCM controls the engine for better fuel economy, emissions control, failure mode detection and storage, and all passive anti-theft system (PATS) functions. If one of the bus wires becomes shorted to ground or voltage, communications can continue at a reduced level. Check the high speed CAN circuits 1908 (WH) and 1909 (BK), between the PCM C175b 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 circuit in the high speed CAN, damage to the DLC C251, damage to the PCM C175b, or a problem in the in-line connector. Since both the PCM and the instrument cluster share network termination responsibilities, a problem in either of these modules can result in a high speed CAN failure. For additional PATS information, refer to ANTI-THEFT - PATS . For additional PCM information, refer to the INTRODUCTION - GASOLINE article. For removal and installation information, refer to ELECTRONIC ENGINE CONTROLS - 2.3L or ELECTRONIC ENGINE CONTROLS - 3.0L (4V) .