Initial Inspection and Diagnostic Overview

1. Visually inspect the components of the EGR system.

VISUAL INSPECTION CHART

Mechanical

^ Loose, leaking, or damaged vacuum lines
^ EGR valve stuck open
^ EGR valve attaching bolts loose or missing
^ EGR valve flange gasket damaged or leaking

Electrical

^ Damaged connectors
^ Damaged insulation
^ Damaged components that affect EGR
^ Damaged EGR components

2. Exercise the wiring harness and connectors for the EGR components. Check for looseness, corrosion, or other damage. This must be done until the engine reaches normal operating temperature for activation of all EGR system components.

3. Check the vacuum lines and connections for looseness, pinching, leakage, splitting, blockage, damage or liquid contamination.

4. If the vehicle System Inspection is OK, proceed to the Pinpoint Tests. Pinpoint Tests