Powertrain Management: Description and Operation

PURPOSE
Computerized Engine Control (CEC) Systems electronically regulate the air/fuel mixture, idle speed and ignition timing to achieve optimum[1] engine performance.

INFORMATION STRUCTURE
Information in this section is divided into the following four major sub-headings:

COMPUTERS AND
CONTROL SYSTEMS Addresses the on-board computer system and components as related to engine management. Consult this section for information regarding on-board diagnostics, sensor inputs, computer outputs, etc.

EMISSION CONTROL
DEVICES Addresses emission related systems and components only. Includes (but is not limited to) Exhaust Gas Recirculation (EGR) systems, Evaporative Emission (EVAP) systems, Positive Crankcase Ventilation (PCV) systems, Exhaust Emission controls, Air Injection Systems (AIS), etc.


FUEL SUPPLY AND
AIR INDUCTION
SYSTEMS Focuses on systems and components related to fuel and intake air delivery. Does NOT include information regarding electronic engine controls.

IGNITION SYSTEM Focuses on primary and secondary ignition systems and components. Does NOT include information regarding electronic engine controls.


[1] Optimum performance means the best possible compromise between the demands of high power, low fuel consumption, and the cleanest possible exhaust emissions.

ABBREVIATIONS:


ACP Air Conditioning Programmer
ALDL Assembly Line Data Link
CTS Coolant Temperature Sensor
DERM Diagnostic Energy Reserve Module (part of SIR)
DIS Distributorless Ignition System
ECM Engine Control Module
EECS Evaporative Emission Control System
EGR Exhaust Gas Recirculation
ESC Electronic Spark Control
EST Electronic Spark Timing
IAC Idle Air Control
IAT Intake Air Temperature
MAP Manifold Air Pressure
[1][2]PCV Positive Crankcase Ventilation
PROM Programable Read Only Memory
PSPS Power Steering Pressure Switch
P/N Park/Neutral
SES Service Engine Soon
SIR Supplemental Inflatable Restraint
TBI Throttle Body Injection
TCC [1][2]Torque Converter Clutch
TPS Throttle Position Sensor
VSS Vehicle Speed Sensor