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P3499 — Cylinder 2 Deactivationintake Valve Performance

Manufacturer-specificPowertrain (engine & transmission)

This code indicates that the engine computer has detected a performance issue with the intake valve deactivation system specifically on cylinder 2. Cylinder deactivation systems shut off certain cylinders to improve fuel economy, and this code triggers when the intake valve on cylinder 2 fails to properly deactivate or reactivate as commanded.

Symptoms

What causes it — most likely first

1. Failed cylinder 2 intake deactivation solenoid

The oil control solenoid that directs oil pressure to deactivate the intake valve can become stuck or fail electrically, preventing proper valve operation.

2. Collapsed or stuck intake valve lifter/rocker arm

The mechanical lifter or rocker arm on cylinder 2 can fail internally, collapsing or sticking so it cannot transition between active and deactivated states.

3. Low or contaminated engine oil

The deactivation system relies on precise oil pressure; low oil levels or sludge-contaminated oil can starve the solenoid and lifter, causing a performance failure.

4. Wiring or connector fault

An open circuit, short to ground, or corrosion in the wiring harness connected to the cylinder 2 intake deactivation solenoid will prevent it from functioning.

5. Failed PCM/ECM

A failure in the engine computer's internal driver for the solenoid circuit is extremely rare and should only be considered after all mechanical and wiring possibilities are eliminated.

How it's diagnosed

  1. Verify engine oil level and condition; top off or change the oil if it is low or heavily contaminated with sludge.
  2. Inspect the wiring and electrical connector at the cylinder 2 intake deactivation solenoid for damage, corrosion, or loose pins.
  3. Test the resistance of the cylinder 2 intake deactivation solenoid and compare it to manufacturer specifications; apply direct power and ground to verify mechanical click operation.
  4. Check oil pressure to the cylinder deactivation system and inspect the oil passages for blockages if the solenoid tests okay.
  5. Remove the valve cover to physically inspect the cylinder 2 intake valve lifter/rocker arm for collapse or mechanical binding.

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationManufacturer-specific (P1/B1/C1/U1)
Related codesP3490 — Cylinder 12 Deactivationintake Valve CP3491 — Cylinder 12 Deactivationintake Valve CP3492 — Cylinder 12 Deactivationintake Valve CP3493 — Cylinder 12 Exhaust Valve Control CircP3494 — Cylinder 12 Exhaust Valve Control CircP3495 — Cylinder 12 Exhaust Valve Control Circ

Frequently asked

Can I still drive my vehicle with code P3499?

You can drive cautiously, but the engine may run rough and lack power. Prolonged driving with a stuck deactivation valve can cause catalytic converter damage from unburned fuel, so it should be repaired promptly.

Does this code mean my engine computer (PCM/ECM) is bad?

No, rarely. Mechanics are sometimes quick to blame the computer, but the actual cause is almost always a mechanical failure of the solenoid, lifter, or an oil delivery issue, not the PCM itself.

Will simply changing the engine oil fix this code?

If the oil is severely degraded or low, an oil change might restore proper hydraulic function to the deactivation system. However, if the solenoid or lifter is already mechanically damaged, fresh oil will not clear the code.

Why does this only affect cylinder 2?

The code is specific to cylinder 2 because the engine computer monitors each cylinder's deactivation hardware individually. The intake valve circuit on cylinder 2 has a dedicated solenoid and lifter, and one of those specific parts has failed independently.