9-7X V8-5.3L (2005)
Variable Valve Timing Actuator: Testing and Inspection
Displacement on Demand (Dod) System Diagnosis
Displacement on Demand (DoD) System Diagnosis
1. Check the engine oil level. Fill, as required.
2. Using the scan tool, check for diagnostic codes within the engine control module (ECM). Refer to Diagnostic System Check - Vehicle. Repair, as
required. See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System Check - Vehicle
3. Verify proper engine oil pressure and operation of the displacement on demand (DoD) oil pressure relief valve. Refer to Oil Pressure Diagnosis
and Testing. See: Testing and Inspection/Component Tests and General Diagnostics/Oil Pressure Diagnosis and Testing (5.3L)
4. Verify proper operation of the DoD system components. Refer to Displacement on Demand (DoD) System Compression Test.
5. Remove the valve lifter oil manifold (VLOM).
6. Verify proper operation of the VLOM. Refer to Displacement on Demand (DoD) Valve Lifter Oil Manifold Diagnosis and Testing. See:
Displacement on Demand (Dod) Valve Lifter Oil Manifold Diagnosis and Testing
7. Replace the DoD valve lifters, as required. Both intake and exhaust lifters should be replaced in pairs. Refer to Valve Lifter Replacement.
