P0306
High Severity

P0306 — Cylinder 6 Misfire Detected

System Subgroup: Powertrain

Quick Diagnosis Guide

Meaning: Code P0306 indicates that the vehicle's onboard computer (ECU) has registered a fault in the powertrain (p) circuits.

Can I still drive? No. Park immediately.

What does the P0306 code mean?

Diagnostic Trouble Code (DTC) P0306 stands for Cylinder 6 Misfire Detected. This is a generic OBD-II trouble code indicating that the ECU has detected system performance parameters that fall outside normal calibrated tolerances.

When this code is logged, the ECU illuminates the dashboard check engine light and triggers a freeze frame record of engine sensor values to help diagnose the issue.

Common Symptoms of Code P0306

Depending on the vehicle make and driving conditions, you may observe the following symptoms:

  • Heavy engine vibration
  • Exhaust sputtering
  • Flashing MIL

What causes the P0306 fault code?

Root causes for a P0306 code typically include:

  • Potential Cause 1: Failing spark plug or coil pack on Cylinder 6
  • Potential Cause 2: Fuel injector circuit problem
  • Potential Cause 3: Mechanical valve failure

Repair Database Status

No verified vehicle-specific workshop fix is currently logged in our mobile mechanic database for this code. Refer to the diagnostic checklist below to isolate the fault.

Step-by-Step Diagnostic & Inspection Checklist

To inspect and troubleshoot a P0306 code, mechanics follow these validation steps:

  • Step 1: Identify the misfire on Cylinder 6 using OBDAssistant.
  • Step 2: Inspect coil wiring harness for Cylinder 6.

Estimated Repair Cost Band

$60 - $250.

Note: Repair estimates vary based on vehicle make, model, local labor rates, and whether you require a full parts replacement.

Related Trouble Codes

If your scan tool registers other codes, check out these related guides:

Frequently Asked Questions

What does a Cylinder 6 misfire mean?

It means the cylinder number 6 is failing to complete proper fuel combustion.