Actron GM Code Scanner CP9001 - Manual (Page 8)

8
Reading Codes
Using the Code Scanner to Read Codes
1) Safety First!
• Set the parking brake.
• Put shift lever in PARK (automatic
transmission) or NEUTRAL
(manual transmission).
• Block the drive wheels.
• Make sure ignition key is in OFF
position.
2) Test the “Check Engine” Light
(Also called “Service Engine Soon”,
“Service Engine Now” or labeled
with a small engine picture.)
• Turn ignition key from OFF to ON
position, but do not start the
engine.
• Verify that the light turns on.
• The connecter is located under the
dashboard on the driver’s side.
Exceptions:
–LeMans: Located behind passen-
ger side kick panel. Remove snap-
on cover for access.
–Fiero: Located in the center
console behind cover panel.
–Corvette: Sometimes located in
centerconsole behind ashtray.
Consult service manual for exact
location.
• The connector may be in full view, or
it may be recessed behind a panel.
An opening in the panel allows
access to recessed connectors.
O
FF
ON
• If the light does not turn on, you
have a problem with this circuit
which must be repaired before
proceeding. Refer to the “Diagnos-
tic Circuit Check” procedure in
your vehicle service manual. (See
manual listings on page 4.)
• Turn ignition key OFF.
3) Have a Pencil
and Paper
Ready
This is for
writing down
all the codes.
4) Find the Computer Test Connector
• Service manuals call this connec-
tor the Assembly Line Diagnostic
Link (ALDL) connector. It may also
be called the Assembly Line
Communication Link (ALCL) or
simply test connector.
• The connector may have a slip-on
cover labeled “Diagnostic
Connector.” Remove cover for
testing. Replace cover after
testing. Some vehicles require this
cover in place for proper operation.
5) Verify Ignition Key is OFF
OF
F
ON