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P codepowertrainMedium severity

P3497Cylinder Deactivation System Bank 2

The cylinder deactivation system on engine bank 2 is not responding correctly when the PCM commands cylinders on or off.

Definition

Engines with cylinder deactivation (GM AFM/DFM, Chrysler MDS, Honda VCM) collapse lifters or hold valves closed on selected cylinders during light load to save fuel. The PCM verifies the bank 2 deactivation hardware responded — via oil pressure, solenoid feedback, and crankshaft speed — and sets P3497 when the bank fails to deactivate or reactivate as commanded. Expect the MIL, possible misfires or lifter tick on bank 2 cylinders, reduced fuel economy, and on some engines a risk of lifter and camshaft damage if the fault is ignored.

Common causes

  • Low oil level, worn-out oil, or incorrect oil viscosity reducing control pressure to the deactivation hardware
  • Faulty cylinder deactivation solenoid or valve lifter oil manifold (VLOM) on a bank 2 cylinder
  • Collapsed or mechanically failed deactivation lifter
  • Clogged oil passages or solenoid screens from sludge
  • Wiring or connector fault in a bank 2 solenoid circuit
  • Inaccurate engine oil pressure sensor feeding the PCM bad data

Common misdiagnoses

  • Ignition coils and spark plugs replaced for the resulting bank 2 misfire
  • Fuel injectors replaced when the miss is a collapsed lifter
  • Lifters replaced when the actual fault is a solenoid, VLOM, or low oil pressure
  • PCM replacement for an oil-supply problem

Troubleshooting steps

  1. 1.Check oil level and condition

    Verify the level is correct and the oil is the specified viscosity (e.g., 0W-20/5W-30 per the cap); deactivation systems are very sensitive to low or degraded oil.

  2. 2.Scan for companion codes

    Misfire codes on bank 2 cylinders (e.g., P0304/P0306/P0308 on a V8) or individual solenoid circuit codes point to which cylinder's hardware failed.

  3. 3.Command deactivation with a bidirectional scan tool

    Activate each bank 2 solenoid at idle and watch for the RPM/roughness change that confirms the cylinder actually drops out.

  4. 4.Verify engine oil pressure with a mechanical gauge

    Compare actual pressure at hot idle and 2,000 RPM against spec; inadequate pressure prevents lifter unlocking regardless of solenoid operation.

  5. 5.Inspect the solenoids/VLOM and screens

    Remove the manifold or solenoids and check the filter screens for debris; measure solenoid coil resistance against spec (typically single-digit ohms).

  6. 6.Mechanically inspect suspect lifters

    If a cylinder still misfires with the solenoid proven good, pull the rocker cover and check for a collapsed lifter or worn cam lobe before reassembly.

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