Generic OBD-II OBD-II Error Code P0305

Generic OBD-II OBD-II Critical Misfire

Model: OBD-II | Code: P0305

Applicable Systems
OBD-II

Symptoms

An engine cylinder misfire has been detected. Rough running and increased emissions may result.

Possible Causes

  • Ignition system component failure (spark plug, coil, or wire)
  • Fuel injector not delivering fuel properly
  • Mechanical issue affecting compression in the cylinder

Troubleshooting Steps

  1. Step 1: Inspect spark plugs and ignition coils for the affected cylinder
    Faulty ignition component identified
  2. Step 2: Test fuel injector operation and pulse
    Injector operating correctly
  3. Step 3: Perform compression test on the affected cylinder
    Compression within specification

How to Reset

To reset: Clear the DTC after repairing the misfire cause and verify smooth idle.

Source: SAE J2012 OBD-II Diagnostic Trouble Codes, SAE International

Category: OBD-II