The
DLC
(
Data
Link
Connector
or
Diagnostic
Link
Connector
)
is
the
standardized
16
-
cavity
connector
where
diagnostic
scan
tools
interface
with
the
vehicle
'
s
on
-
board
computer
.
The
DLC
is
usually
located
12
inches
from
the
center
of
the
instrument
panel
(
dash
),
under
or
around
the
driver
'
s
side
for
most
vehicles
.
If
the
Data
Link
Connector
is
not
located
under
the
dashboard
,
a
label
should
be
there
revealing
its
location
.
For
some
Asian
and
European
vehicles
,
the
DLC
is
located
behind
the
ashtray
and
the
ashtray
must
be
removed
to
access
the
connector
.
If
the
DLC
cannot
be
found
,
refer
to
the
vehicle
'
s
service
manual
for
the
location
.
Figure 1-3: The DLC connector (left) can be found in the
area of the car interior seen at right (black arrow).
2.3 Location of the Data Link Connector (DLC)
2
.
4
OBD
II
Definitions
Powertrain Control Module (PCM) -
the
OBD
II
terminology
for
the
on
-
board
computer
that
controls
the
engine
and
the
drive
train
.
Malfunction Indicator Light (MIL) -
Malfunction
Indicator
Light
(
Service
Engine
Soon
,
Check
Engine
)
is
a
term
used
for
the
light
on
the
instrument
panel
.
It
is
to
alert
the
driver
and
/
or
the
repair
technician
that
there
is
a
problem
with
one
or
more
of
vehicle’s
systems
and
may
cause
emissions
to
exceed
federal
standards
.
If
the
MIL
illuminates
with
a
steady
light
,
it
indicates
that
a
problem
has
been
detected
and
the
vehicle
should
be
serviced
as
soon
as
possible
.
Under
certain
conditions
,
the
dashboard
light
will
blink
or
flash
.
This
indicates
a
severe
problem
and
flashing
is
intended
to
discourage
vehicle
operation
.
The
vehicle
onboard
diagnostic
system
can
not
turn
the
MIL
off
until
necessary
repairs
are
completed
or
the
condition
no
longer
exists
.
Diagnostic Trouble Codes (DTC) –
These
identify
which
section
of
the
emission
control
system
has
malfunctioned
.
Freeze Frame Data –
When
an
emissions
related
fault
occurs
,
the
OBD
II
system
not
only
sets
a
code
,
but
also
records
a
snapshot
of
the
vehicle
operating
parameters
to
help
in
identifying
the
problem
.
This
set
of
values
operating
parameters
to
help
in
identifying
the
problem
.
This
set
of
values
is
referred
to
as
Freeze
Frame
Date
and
may
include
important
engine
is
referred
to
as
Freeze
Frame
Date
and
may
include
important
engine
parameters
such
as
engine
RPM
,
vehicle
speed
,
air
flow
,
engine
load
,
fuel
pressure
,
fuel
trim
value
,
engine
coolant
temperature
,
ignition
timing
advance
,
or
closed
loop
status
.
3. Using the Scan Tool
3.1 Tool Description - PlusQuip EQP-120
eQP-120 User’s Manual
4
eQP-120 User’s Manual
5
