Powertrain Control Module

Powertrain Control Module (PCM), located behind right end of instrument panel, receives inputs from vehicle speed sensor, servo diaphragm position sensor, cruise control switch and brake release switch. Based on these inputs, PCM controls vacuum valves at servo. PCM prevents system engagement at speeds of less than 25 MPH. PCM is not serviceable; if defective, it must be replaced. System faults are stored as codes in PCM memory.