Vehicle On-Board Diagnostics (OBD) System Check

This should be the starting point of any driveability or symptom diagnosis. Perform the "Vehicle OBD" system check as defined in the diagnostics section of this manual. This check verifies the communication integrity of all on-board control modules and their self-diagnostic capabilities. If Diagnostic Trouble Codes (DTCs) are stored, go directly to the numbered DTC chart. Testing and Inspection