Pretest Inspection

Before proceeding with diagnosis, the following precautions must be followed:

• Vehicle must have a fully charged battery and functional charging system.
• Always start at SYMPTOM ID TEST 1A: IDENTIFYING VEHICLE EQUIPMENT & SYSTEM PROBLEMS. Starting with any other test may result in incorrect results.
• Only perform test steps indicated. It is NOT necessary to perform all steps in a test.
• VEHICLE COMMUNICATIONS article should only be used when instructed to do so by another test. Always start at SYMPTOM ID TEST 1A: IDENTIFYING VEHICLE EQUIPMENT & SYSTEM PROBLEMS.
• Turn ignition switch to OFF position before disconnecting or connecting components.
• Use extreme care when connecting or disconnecting wiring during testing to prevent accidental grounding or shorting.
• DO NOT use a test light in place of a voltmeter.
• Always disconnect scan tool after use.
• Always disconnect scan tool before charging battery.
• Always perform appropriate verification test after repairs are made.