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P0309

Overview

Code

P0309

Code Type

P

Code Class

P0

System

Engine

Severity Level

High

Emissions Related

true

Drivability Impact

Major

Diagnostic Protocol

OBD2

Freeze Frame Useful

true

Code Definition

Diagnostic trouble code P0309 indicates a misfire detected in cylinder 9 (if equipped)

Symptoms

Engine vibration; Rough idle; Loss of power

Overview applies to this diagnostic code.

Affected Systems

On This Page

  • Code Definition

  • Symptoms

  • Affected Systems

  • Possible Causes

  • Diagnostic Steps

  • Drive Safety Notes​

More Resources

Cylinder-specific combustion and engine balance

Possible Causes

Faulty spark plug/coil; Fuel injector issues; Compression loss

Diagnostic Steps

1 Inspect ignition components; 2 Test fuel injector; 3 Perform compression test if needed; 4 Swap ignition components with another cylinder

Drive Safety Notes

Continued misfire may damage catalytic converter

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