What this code means

The cylinder deactivation system (Active Fuel Management/Multi-Displacement) for Bank 1 has detected a fault. The system deactivates cylinders during light load for fuel savings.

Symptoms

• Check Engine Light
• Engine vibration at highway cruise
• No cylinder deactivation occurring
• Reduced fuel economy
• Engine sounds different than normal
• MIL with misfire-like symptoms

Common causes

• Deactivation solenoid failure
• VLOM (valve lifter oil manifold) stuck
• Low oil pressure to lifters
• Collapsed deactivation lifter
• Oil passage blockage

Diagnostic steps

1. Read cylinder deactivation status PIDs
2. Command deactivation on/off with scan tool
3. Check oil pressure at VLOM
4. Test deactivation solenoid resistance
5. Monitor individual cylinder contribution

Repair notes

Replace faulty deactivation solenoid or VLOM assembly. Collapsed lifters require cylinder head work. Use AFM-compatible oil and filter.

Other Powertrain codes on this vehicle