HomeP0304 · Engine misfire detected · Cylinder 4
Powertrain

P0304

Engine misfire detected · Cylinder 4

P0304
Reference meaning

What does this code mean?

P0300 indicates random or multiple-cylinder misfire. P0301–P0308 identify the numbered cylinder. Ignition, fuel delivery, compression, air leaks or mechanical timing can cause misfire. Use misfire counters, freeze-frame data and appropriate tests to narrow the cause. A flashing malfunction light can signal a misfire that may damage the catalyst.

A code identifies a detected condition, not a part that must automatically be replaced.

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A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.

Manufacturer communications

3

Original wording in English

TSB-070 REV 1

KIA

Reported code forms P0304

KIA: PCM UPGRADE FOR P0304 DUE TO VCM MOTOR VARIATION. PROCEDURE TO UPGRADE THE POWERTRAIN CONTROL MODULE (PCM) OF SOME VEHICLES. THIS REFLASH HAS ENHANCED VCM (VARIABLE CHARGE MOTION) ACTUATOR LOGIC TO IMPROVE A ROUGH…

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TSB-070

KIA

Reported code forms P0304

KIA: ECM UPGRADE FOR P0304 DUE TO VCM MOTOR VARIATION. PROVIDES THE PROCEDURE TO UPGRADE THE POWERTRAIN CONTROL MODULE (PCM) OF SOME MODEL YEAR VEHICLES. REFLASH HAS ENHANCED VCM (VARIABLE CHARGE MOTION) ACTUATOR LOGIC…

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TSB-059

KIA

Reported code forms P0304

KIA: SERVICE ACTION: PCM UPGRADE DTC P0304 CYLINDER MIS FIRE WITH 2.0L ENGINE AND A/T LOGIC (SA0250 SOME VEHICLES MAY EXPERIENCE A MIL ON WITH DTC P0304 STORED IN MEMORY. IN MOST CASES THE DTC IS SET ONLY DURING A COLD…

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Check vehicle applicability

1

A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.

MakeModelModel year
KiaFORTE2010

Before replacing a part

Record codes and freeze-frame data. Check battery condition, related codes and visible wiring or hose damage. Follow the vehicle's diagnostic procedure and test results before replacing parts.

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Sources and interpretation

These explanations are editorial summaries of the linked manufacturer material. PDF page numbers count from the first file page. Original publications are in English; translations are reference aids. A cited edition is not a claim that it is the manufacturer's latest instruction.

  1. 01 13 14 / 2033805 · Engine, Misfire Diagnostic Aid ↗

    Volkswagen Group of America · PDF page(s) 1, 2 ·

  2. 2024–2025 MY OBD System Operation Summary for Gasoline Engines ↗

    Ford Motor Company · PDF page(s) 9, 10 ·

Source check date · 2026-10-27

Can I keep driving?

A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.