Section 131 (Engine Vacuum Diagrams): Introduction

WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Information in this article also applies to Cab & Chassis Sierra and Cab & Chassis Silverado.

This article contains underhood views or schematics of vacuum hose routing. Use these vacuum diagrams as a guide during the visual inspection in appropriate BASIC DIAGNOSTIC PROCEDURES article. This will assist in identifying improperly routed vacuum hoses which may cause driveability and/or computer-indicated malfunctions. Always verify vacuum hose routing using underhood emission and vacuum label (if equipped) for specific applications.

NOTE: If underhood vacuum label and diagram in manual differ, underhood label should always take precedent, unless it is suspected of not being correct application.