Initial Inspection and Diagnostic Overview

Diagnostic Starting Point - Engine Mechanical (5.3L)

Begin the system diagnosis by reviewing the Disassembled Views (5.3L) ([1][2]Diagrams)Disassembled Views (6.0L) ([1][2]Diagrams) , Engine Component Description (5.3L) (Engine Component Description)Engine Component Description (6.0L) (Engine Component Description) , Lubrication Description - Main Pressure Below 55 psi with Cylinder Deactivation (Active Fuel Management) Off (5.3L) (Description and Operation) , Lubrication Description - Main Pressure Above 55 psi with Cylinder Deactivation (Active Fuel Management) Off (5.3L) (Description and Operation) , Lubrication Description - Main Pressure Below 55 psi with Cylinder Deactivation (Active Fuel Management) On (5.3L) (Description and Operation) , Lubrication Description - Main Pressure Above 55 psi with Cylinder Deactivation (Active Fuel Management) On (5.3L) (Description and Operation) and Cylinder Deactivation (Active Fuel Management) System Description . Reviewing the description and operation information helps you determine the correct symptom diagnostic procedure when a condition exists. Reviewing the description and operation information also helps you determine if the condition described by the customer is normal operation. Refer to Symptoms - Engine Mechanical (5.3L) (- Symptoms - Engine Mechanical)Symptoms - Engine Mechanical (6.0L) (- Symptoms - Engine Mechanical) in order to identify the correct procedure for diagnosing the system and where the procedure is located.