Vacuum Diagrams: Introduction

This article contains underhood views or schematics of vacuum hose routing. Use these vacuum diagrams during visual inspection in BASIC DIAGNOSTIC PROCEDURES article. Canada and some states or metropolitan areas in the United States require periodic emission, or Inspection/Maintenance (I/M) tests. Use these vacuum diagrams during a visual inspection for one of these tests. This will assist in identifying improperly routed vacuum hoses, which may cause driveability and/or computer-indicated malfunctions.