P3478 OBD II Trouble Code Cylinder 10 Exhaust Valve Control Circuit Performance

How to quickly diagnose and repair, and causes of a P3478 electrical code which indicates a performance problem in the cylinder 10 exhaust valve control circuit.

Symptoms of P3478 OBD II Trouble Code

  • Increased fuel consumption
  • Poor engine performance
  • Engine misfire
  • Service engine soon light illuminated
  • Check engine light illuminated

Common Causes of P3478 OBD II Trouble Code

  • Faulty variable valve timing solenoid
  • Low engine oil level or pressure
  • Restricted oil passage
  • Faulty or damaged wiring
  • Corroded, damaged or loose connector
  • Defective ECM

Severity of P3478 OBD II Trouble Code

The severity of this code can vary tremendously from moderate to severe depending on the specific symptoms of the malfunction. A misfire requires immediate attention because it can cause permanent damage to internal engine components.