Powertrain Control Module (PCM)

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 PCM is on the SCP communication network. 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, or if some but not all termination resistors are lost, communications can continue at a degraded level. Check the SCP circuits 915 (PK/LB) and 914 (TO/OG) between the PCM C175 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 SCP network, damage to the DLC C251, damage to the PCM C175, or a problem in the in-line connector. For additional PATS information, refer to ANTI-THEFT . For additional PCM information, refer to INTRODUCTION - CNG, FLEX-FUEL & GASOLINE .