12 Section 1 Introduction to Automotive Technology
Computer System
The computer system uses electronic and electrical
devices to monitor and operate various mechanical
systems. Electronic controls are provided for the
engine, drive train, suspension, instrumentation,
restraint, and other systems. The use of computer
systems has improved vehicle effi ciency and
dependability. Additionally, all on-board computers
now have a powerful self-diagnostic capability.
Today’s vehicle computers can troubleshoot every
major assembly, circuit, component, and system
almost instantly.
There are three major parts of an automotive com-
puter system:
• Sensors—Sensors are input devices that can
produce or modify electrical signals with a
change in a condition, such as motion, tempera-
ture, pressure, speed, location, etc. The sensors
are the “eyes, ears, and nose” of the computer
control system.
• Electronic control module—The electronic con-
trol module is a computer (complex electronic
circuits) that uses signals from input devices
(sensors) to control various output devices
Intake
manifold
Intake
valve
Timing
chains
Combustion
chamber
Crankshaft
pulley
Crankshaft
Oil pan Piston rings Connecting rod
Piston
Exhaust
manifold
Block
Cylinder
head
Valve spring
Camshaft
Figure 1-10. Study the major parts from the front view of a modern engine. (Ford)