This manual describes common test procedures used by experienced
service technicians. Many test procedures require precautions to avoid
accidents that can result in personal injury, and/or damage to your
vehicle or test equipment. Always read your vehicle's service manual
and follow its safety precautions before and during any test or service
procedure. ALWAYS observe the following general safety precautions:
When an engine is running, it produces carbon monoxide, a
toxic and poisonous gas. To prevent serious injury or death
from carbon monoxide poisoning, operate the vehicle ONLY
in a well-ventilated area.
To protect your eyes from propelled objects as well as hot
or caustic liquids, always wear approved safety eye
When an engine is running, many parts (such as the coolant
fan, pulleys, fan belt etc.) turn at high speed. To avoid serious
injury, always be aware of moving parts. Keep a safe distance
from these parts as well as other potentially moving objects.
Engine parts become very hot when the engine is running.
To prevent severe burns, avoid contact with hot engine
Before starting an engine for testing or trouble-shooting, make
sure the parking brake is engaged. Put the transmission in
park (for automatic transmission) or neutral (for manual
transmission). Block the drive wheels with suitable blocks.
Connecting or disconnecting test equipment when the
ignition is ON can damage test equipment and the vehicle's
electronic components. Turn the ignition OFF before
connecting the Code Reader to or disconnecting the Code
Reader from the vehicle's Data Link Connector (DLC).
To prevent damage to the on-board computer when taking
vehicle electrical measurements, always use a digital
multimeter with at least 10 MegOhms of impedance.
The vehicle's battery produces highly flammable hydrogen
gas. To prevent an explosion, keep all sparks, heated items
and open flames away from the battery.
Don't wear loose clothing or jewelry when working on an
engine. Loose clothing can become caught in the fan,
pulleys, belts, etc. Jewelry is highly conductive, and can
cause a severe burn if it makes contact between a power
source and ground.