Malibu V6-3.1L VIN J (2002)
Engine Control Module: Description and Operation
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 Powertrain Control Module (PCM) contains the remainder of the logic of the theft deterrent system. If a class 2 message containing a valid
password is received from the BCM, the PCM will continue to allow the fuel injectors to operate. The PCM will allow the fuel injectors to operate until
it decides there is no valid password coming from the BCM If the PCM does not receive a class 2 message, or receives a class 2 message with an
incorrect password, the engine will crank and will not run or will start and stall immediately.
