P3490

  • Powertrain
  • Manufacturer-specific
  • Emissions
SeveritySeverity level 3 of 5: Diagnose soon.

Diagnose soon

Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.

Standard definition

Cylinder Deactivation System Performance Bank 1

This code is in our catalogue but has not yet been through editorial review, so the guidance below is limited to what our structured data supports. We publish deeper diagnostic content only after a code has been reviewed — here is why.

In plain English

The engine control module has detected that the cylinder deactivation system on bank 1 is not performing as expected. Closed-loop monitoring of pressure response, valve timing or misfire counters during transitions indicates the system fails to deactivate or reactivate cylinders within calibrated limits.

A trouble code records what a control module measured. It does not identify which part failed. Test before replacing anything.

Can I keep driving?
Safe to drive
Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.
Urgency
Diagnose soon
Will it pass emissions
No
Check engine light
Solid
Clearing the light
A completed drive cycle is normally required before the monitor re-runs and the light can clear.
Likely causes
#CauseHow oftenComponent
1Switching lifter stuck or wornVery common
2Insufficient oil pressureCommon
3Solenoid slow or contaminatedCommon

Ordering reflects how often each cause is responsible in general, not a probability for your vehicle. Confirm by testing.

Components involved
  • Cylinder Deactivation Solenoid
  • Lifter
  • Oil Control Valve
Sources
Definition
Generic code set (SAE J2012 / ISO 15031-6) via the OBDexopen database, dedicated to the public domain under CC0-1.0.
Diagnostic guidance
Written and reviewed in-house. See our editorial policy.
Review status
Awaiting review

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