Pretest Inspection

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

• Vehicle must have a fully charged battery and functional charging system.
• Only perform test steps indicated. It is NOT necessary to perform all steps in a test.
• VEHICLE COMMUNICATIONS tests should only be used when instructed to do so by another test. Always start at TEST 1A: BLANK DRB-II MESSAGE SCREEN.
• Always perform VERIFICATION TEST after repairs are made.
• At the end of each test step, reconnect all wires and install any components removed for testing.
• 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 DRB-II after use.
• Always disconnect DRB-II before charging battery.