Engine Control Module: Description and Operation
DescriptionThe Powertrain Control Module (PCM) controls spark advance and fuel injection for all driving conditions. The PCM monitors input signals from the following components as part of its ignition control function to determine the required ignition timing:
^ Ignition Control Module (IC Module).
^ Engine Coolant Temperature (ECT) sensor.
^ Manifold Absolute Pressure (MAP) sensor.
^ Transaxle Range (TR) switch.
^ Throttle Position (TP) sensor.
^ Vehicle Speed Sensor (VSS).
^ Knock Sensor (KS).
Control Module Function
The Control Module supplies a buffered voltage to various sensors and switches. The input and output devices in the control module include an analog to digital converters, signal buffers, counters, and special drivers. The Control Module controls most components with electronic switches which complete a ground circuit when turned ON. These switches are arranged in groups of 4 and 7 called one of the following:
^ Quad Driver Module
^ Output Driver Modules
The surface mounted Quad Driver Module can independently control up to 4 outputs (Control Module) terminals. The Output Driver Modules can independently control up to 7 outputs. Not all outputs are always used.