P3403
Sistema
Powertrain (Engine)
Escáner necesario
Full-system scanner (engine, ABS, SRS, transmission, service resets)

Cylinder 3 Deactivation System Performance

Understand P3403, common causes, and the right FOXWELL scanner to diagnose it.

Active Fuel Management (AFM/DOD) system cannot deactivate or reactivate cylinder 3 as commanded — common on GM V6/V8 with cylinder deactivation.

Síntomas habituales

  • Ticking or misfire on affected cylinder
  • P0303 may accompany
  • Rough idle
  • Check engine light
  • Reduced fuel economy benefit lost

Causas típicas

  • Failed AFM lifter on cylinder 3
  • Low oil pressure to AFM solenoids
  • Wrong oil viscosity or low oil level
  • AFM solenoid oil passage blockage
  • Collapsed AFM lifter on cylinder 3

¿Qué escáner necesita?

Full-system scanner (engine, ABS, SRS, transmission, service resets)

Use datos en vivo y freeze frame antes de cambiar piezas. Códigos ABS, SRS y U suelen requerir un escáner de todos los sistemas.

Consejos de diagnóstico

  • Registre el freeze frame cuando se active el código
  • Borre el código solo tras corregir la causa
  • Revise códigos pendientes relacionados
  • Verifique que la batería esté por encima de 12,4 V antes de sospechar sensores

Escáneres FOXWELL recomendados

Preguntas frecuentes

Can I diagnose P3403 with a basic code reader?
P3403 may set in the engine module, but related diagnostics often benefit from an enhanced or full-system scanner with live data and freeze frame.
Is it safe to drive with P3403?
It depends on the code and symptoms. Flashing check engine lights and misfire codes should be addressed immediately. Consult a professional if unsure.