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P3479

Cylinder Deactivation Solenoid Bank 1 Control Circuit Open

The engine control module has detected an open circuit at the bank 1 cylinder deactivation solenoid. The solenoid routes oil pressure to the switching lifters; an open circuit prevents activation and the system disables deactivation requests on bank 1.

  • Check engine light: Yes
  • Emissions related: Yes
  • Repair difficulty: hard

Common causes

Ordered by how often each turns out to be the cause.

  • Solenoid coil openCommon
  • Wiring or connector openPossible
  • ECM driver failedLess likely

Parts involved

  • Cylinder Deactivation Solenoid
  • Engine Wiring Harness
  • ECM

P3479 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.