Powertrain Control Module (PCM) Description

Powertrain Control Module (PCM) Description:

The powertrain has electronic controls to reduce exhaust emissions while maintaining excellent driveability and fuel economy. The Powertrain Control Module (PCM) is the control center of this system. The PCM monitors numerous engine and vehicle functions. The PCM constantly looks at the information from various sensors and other inputs, and controls the systems that affect vehicle performance and emissions. The PCM also performs the diagnostic tests on various parts of the system. The PCM can recognize operational problems and alert the driver via the Malfunction Indicator Lamp (MIL). When the PCM detects a malfunction, the PCM stores a Diagnostic Trouble Code (DTC). The problem area is identified by the particular DTC that is set. The control module supplies a buffered voltage to various sensors and switches. Review the components and wiring diagrams in order to determine which systems are controlled by the PCM.


The PCM verifies that the password received from the theft deterrent control module via the Class 2 serial data circuit is correct. The theft deterrent control module can learn only one enable password. If the enable password is correct, the PCM enables the starting and fuel delivery systems. The PCM disables the starting and fuel delivery systems if any of the following conditions occur:
^ The enable password is incorrect.
^ The system disable password is sent by the theft deterrent control module.
^ No passwords are received - there is no communication with the theft deterrent control module.