General Description

Figure 1 - Typical Inputs and Outputs:

General Description
The Powertrain Control Module (PCM) will be referred to as a control module. The control module located on the right hand fender well, is designed to maintain exhaust emission levels to Federal or California standards, while providing excellent driveability and fuel efficiency. The functions of the system are based on data gathered by the sensors and switches located throughout the vehicle. The Powertrain Control Module maintains control over fuel delivery, ignition, idle air flow, the fuel pump and other system components, while monitoring the system for faulty operation with its diagnostic capabilities. The Powertrain Control Module language for communicating the source of the malfunction is a system of diagnostic trouble codes. When it finds a problem, it may illuminate the Malfunction Indicator Lamp (MIL) on the instrument panel and a Diagnostic Trouble Code (DTC) will be stored in the Control Module memory. Which can identify the problem areas to aid the technician in making repairs.
The PCM in this vehicle is programmable.
When replacing the PCM, it will be mandatory to program the EEPROM and transfer the (Knock Sensor (KS) calibrator) PROM to the new PCM.
The control module monitors numerous engine and vehicle functions and controls the following operations:
- Fuel control
- Ignition Control (IC)
- Knock Sensor (KS) system
- Generator
- Evaporative Emission (EVAP) Purge
- A/C Clutch Control
- Cooling Fan Control

Control Module Function
The Control Module supplies a buffered voltage to various sensors and switches.
The input/output devices in the control module include 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 either a surface mounted Quad Driver Module, which can independently control up to 4 outputs (Control Module) terminals or Output driver Modules which can independently control up to 7 outputs. Not all outputs are always used.