OTC Tools Code Scanner Manual Del Usuario página 11

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) Perform
Visual Inspection.
Doing a thorough visual and "hands-
on" underhood inspection before
starting any diagnostic procedure is
essential!! You can find the cause of
many drivability problems by just
looking, thereby saving yourself a lot
of time.
• Has the vehicle been serviced
recently?
Sometimes things get reconnected
in the wrong place, or not at all.
• Don't take shortcuts. Inspect hoses
and wiring which may be difficult to
see because of location beneath air
cleaner housings, alternators and
similar components.
• Inspect the air cleaner and ductwork
for defects.
• Check sensors and actuators for
damage.
• Inspect all vacuum hoses for:
– Correct routing. Refer to vehicle
service manual, or Vehicle Emission
Control Information (VECI) decal
located in the engine compartment.
– Pinches and kinks.
– Splits, cuts or breaks.
S T
HVAC/
CRUISE
STER
EGR
GAP VAC
REG
FUEL
PRESS
. ..
REG
.S.A.
EGR
VAC
REG
E M
BRAKE BOOSTER
TO TRANS
MODE
FRONT
OF CAR
9RAC2LAB
• Inspect wiring for:
– Contact with sharp edges. (This
happens often.)
– Contact with
hot surfaces,
such as
exhaust
manifolds.
– Pinched,
burned or
chafed
insulation.
– Proper routing and connections.
• Check Electrical Connectors for:
– Corrosion on pins.
– Bent or damaged pins.
– Contacts not properly seated in
housing.
– Bad wire crimps to terminals.
Bent Pins
Problems with connectors are common
in the engine control system. Inspect
carefully. Note that some connectors use
a special grease on the contacts to
prevent corrosion. Do not wipe off!
Obtain extra grease, if needed, from
your vehicle dealer. It is a special type
for this purpose.
3) Prepare Vehicle.
• Turn off all electrical equipment and
accessories in vehicle.
• Keep all vehicle doors closed during
testing.
• Make sure radiator coolant and
transmission fluid are at proper
levels.
• Start the engine and let it idle until
the upper radiator hose is hot and
pressurized and RPM has settled to
warm engine idle speed.
Check for leaks around hose
connections.
11
Corrosion