Field service test fuel injected engines only – Actron GM Code Scanner CP9001 User Manual
Page 25
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3) Turn Ignition Key to ON Position
but DO NOT START THE ENGINE.
•
WARNING: Stay away from the
radiator cooling fan! It may turn on.
• Ignore the flashing Check Engine
light.
4) Computer Controlled Relays and
Solenoids are Turned ON
Exception: Fuel pump and fuel
injectors are OFF. (Refer to vehicle
service manual for any other
exceptions.)
• Make any relay or
solenoid circuit
checks at this
time. Note the
following special
circuit actions...
– Fuel Injected
Engines Only:
The Idle Air
Control (IAC)
motor fully extends (most vehicles)
or moves back and forth.
– Carbureted Engines Only: The
Idle Speed Control (ISC) motor, if
used on vehicle, moves back and
forth. Also, the Exhaust Gas
Recirculation (EGR) solenoid is
energized for 25 seconds.
5) Turn Ignition Key OFF.
• Remove Code Scanner and re-
install connector cover, if supplied.
• The computer system is now back
to normal.
• This completes the Relay and
Solenoid Circuit Test.
Model CP 7676
Automotive Volt/Ohm
Dwell/Tach
10 Megohm V
V
Ohms
RPM
X10
Dwell
4
CYL
5
CYL
CYL
6
CYL
8
4
CYL
5
CYL
CYL
6
CYL
8
OFF
200
2K
200
K
2M
20K
2
20
750
200
20
M
Digital Engine Analyzer
Field Service Test Fuel
Injected Engines Only
This is a quick check of the fuel control
system to verify proper operation -
especially after repair work. Service
manuals call this the “Field Service
Mode”. Do the following:
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.
• 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.)
3) Start the Engine
WARNING: Always operate vehicle
in well ventilated area. Exhaust
gases are very poisonous!
4) Plug the
Code
Scanner into
the Test
Connector.
Put TEST
switch on
ENGINE.
The engine
computer is now
in the “Field
T E S T
ABS
ENGINE
TM
GM 1982 & higher - CP 9001
Ca
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