Powertrain Control Module
NOTE:
Powertrain Control Module (PCM) may also be referred to as Electronic Control Module (ECM) or Vehicle Control Module (VCM). PCM is located either in front of shifter below center console, or on fenderwell in engine compartment.
PCM analyzes all electrical data signals from input devices to control fuel injection, ignition and emissions. PCM includes a backup fail-safe control system. If a malfunction should occur in any PCM controlled systems, in most cases PCM will substitute default settings to maintain necessary engine functions and permit operation of vehicle.
Electronically Erasable Programmable Read Only Memory (EEPROM) is factory-programmed engine calibration data, which modifies PCM for specific transmission, engine, emission, vehicle weight and rear axle ratio application. It can be reprogrammed using Tech II scan tool. EEPROM is permanently soldered into PCM and is cannot replaced separately. If battery voltage is removed, EEPROM information is retained.