For 1990-2009 cars only
- Measure the engine oil level. Fill, as required.
- Using the scan tool, inspect for diagnostic codes within the engine control module (ECM). Refer to Diagnostic System Check - Vehicle . Repair, as required.
- Verify proper engine oil pressure and operation of the active fuel management oil pressure relief valve. Refer to Oil Pressure Diagnosis and Testing .
- Verify proper operation of the active fuel management system components. Refer to Cylinder Deactivation (Active Fuel Management) System Compression Test .
- Remove the valve lifter oil manifold. Refer to Valve Lifter Oil Manifold Replacement .
- Verify proper operation of the valve lifter oil manifold. Refer to Cylinder Deactivation (Active Fuel Management) Valve Lifter Oil Manifold Diagnosis and Testing .
- Replace the active fuel management valve lifters, as required. Both intake and exhaust lifters should be replaced in pairs. Refer to Valve Lifter Replacement .
Important: Active Fuel Management System Diagnosis is applicable for RPO LC9/LY5/LMG/L76.
