P3404
System
Powertrain (Engine)
Scanner som krävs
Full-system scanner (engine, ABS, SRS, transmission, service resets)

Cylinder 4 Deactivation System Performance

Understand P3404, common causes, and the right FOXWELL scanner to diagnose it.

Active Fuel Management (AFM/DOD) system cannot deactivate or reactivate cylinder 4 as commanded — common on GM V6/V8 with cylinder deactivation.

Vanliga symptom

  • Ticking or misfire on affected cylinder
  • P0304 may accompany
  • Rough idle
  • Check engine light
  • Reduced fuel economy benefit lost

Typiska orsaker

  • Failed AFM lifter on cylinder 4
  • Low oil pressure to AFM solenoids
  • Wrong oil viscosity or low oil level
  • AFM solenoid oil passage blockage
  • Collapsed AFM lifter on cylinder 4

Vilken scanner behöver du?

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

Använd live-data och freeze frame innan du byter delar. ABS-, SRS- och U-koder kräver oftast en fullsystems-scanner.

Diagnostiktips

  • Spara freeze frame när koden först sätts
  • Rensa koden först efter att orsaken är åtgärdad
  • Kontrollera relaterade väntande koder
  • Verifiera batterispänning över 12,4 V innan du misstänker sensorer

Rekommenderade FOXWELL-scannrar

Vanliga frågor

Can I diagnose P3404 with a basic code reader?
P3404 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 P3404?
It depends on the code and symptoms. Flashing check engine lights and misfire codes should be addressed immediately. Consult a professional if unsure.