Pretest Inspection

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

• Ensure self-diagnostic tests apply to vehicle being tested. See BODY CONTROL COMPUTER TESTS DIRECTORY table.
• Vehicle must have a fully charged battery and functional charging system.
• Always start at 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.
• Always start at TEST 1A.
• 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 TEST VER-1 after repairs are made.