Cylinder Deactivation (Active Fuel Management) System Diagnosis

Cylinder Deactivation (Active Fuel Management) System Diagnosis

Important: Cylinder Deactivation (Active Fuel Management) System Diagnosis is applicable for RPO LH6/LMG/LY5/LC9/L76.

1. Measure the engine oil level. Fill, as required.
2. Using the scan tool, inspect for diagnostic codes within the engine control module (ECM). Refer to Diagnostic System Check - Vehicle. Repair, as required. Initial Inspection and Diagnostic Overview
3. Verify proper engine oil pressure and operation of the active fuel management oil pressure relief valve. Refer to Oil Pressure Diagnosis and Testing. Testing and Inspection
4. Verify proper operation of the active fuel management system components. Refer to Cylinder Deactivation (Active Fuel Management) System Compression Test. Testing and Inspection
5. Remove the valve lifter oil manifold.
6. Verify proper operation of the valve lifter oil manifold. Refer to Cylinder Deactivation (Active Fuel Management) Valve Lifter Oil Manifold Diagnosis and Testing. Component Tests and General Diagnostics
7. Replace the active fuel management valve lifters, as required. Both intake and exhaust lifters should be replaced in pairs.