Equus 3120 - OBD 2&1 Tool Kit - Manual (Page 3)

Introduction
WHAT IS OBD?
OBD2 & 1 1
E
WHAT IS OBD?
The OBD2 & 1 Tool is designed to work on most Chrysler, Ford,
GM and Toyota OBD1 systems and all
OBD2 compliant vehicles.
One of the most exciting improvements
in the automobile industry was the addition
of on-board diagnostics (OBD) on vehicles,
or in more basic terms, the computer that
activates the vehicle’s “CHECK ENGINE”
light. OBD 1 was designed to monitor manu-
facturer-specific systems on vehicles built
from 1981 to 1995. Then came the develop-
ment of OBD 2, which is on all 1996 cars and light trucks sold in the
United States. These systems are part of a government mandate to
lower vehicle emissions. The sophisticated programs in the vehicle’s
on-board computer system are designed to detect failures in a range
of vehicle systems. Diagnostic information can be accessed through a
Data Link Connector test port specifically designed for this purpose.
For all OBD systems, if a problem is found, the computer turns on the
“CHECK ENGINE” light to warn the driver, and sets a Diagnostic
Trouble Code (DTC) to identify where the problem occurred. A special
diagnostic tool, such as the OBD2 & 1 Tool, is required to retrieve
these codes, which consumers and professionals use as a starting
point for repairs.