Instructions Manual

4-1

Troubleshooting

4.1 Vehicle Inspection

Many problems can be found by performing a visual and “hands-on”

under-the-hood inspection before starting any diagnostic procedure.

• Has the vehicle been serviced recently?

Sometimes things are reconnected in the

wrong place, or not at all.

• Do no

t take shortcuts. Inspect hoses and

wiring which may be difficult to see because

of location (under air cleaner housing,

alternators and similar components).

• Inspe

ct the air cleaner and ductwork for

defects.

• Check sensors and actuators for

damage.

• Inspec

t 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.

• Inspec

t electrical wiring for:

- Damaged insulation caused by sharp

obje

cts (a common problem) or by hot

surfaces such as engine and exhaust

manifold.

- Corroded and broken wires.