OBD-II code · Powertrain (manufacturer / generic)

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.

Is it safe to drive with P3479?

Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.

Common causes

  • Most likelySolenoid coil open
  • PossibleWiring or connector open
  • Less likelyECM driver failed

Repair at a glance

Difficulty
Hard
DIY friendly
Best left to a mechanic
Typical labour
1–5 h
Emissions test
Likely to fail
After the fix
A drive cycle is needed before the light stays off
Parts involved
Cylinder Deactivation Solenoid, Engine Wiring Harness, Ecm

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.