AutoCodes – RAM – P0304 RAM

P0304 RAM Code - Cylinder Misfire Fault Detected

Quick Answer

When a misfire occurs, engine speed will fluctuate. Common causes include Faulty Spark Plug #4, Clogged or faulty Fuel Injector #4, Faulty Ignition Coil #4. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0304 RAM indicates Cylinder Misfire Fault Detected .
Common causes: Common causes include Faulty Spark Plug #4, Clogged or faulty Fuel Injector #4, Faulty Ignition Coil #4.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 1,363

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on May 02, 2021

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0304 RAM Description

When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the Crankshaft Position (CKP) sensor signal to vary, the Engine Control Module (ECM) can determine that a misfire is occurring.

OBDII Code P0304 RAM - Cylinder Misfire Fault Detected - AutoCodes.com — P0304 RAM Code - Cylinder Misfire Fault Detected

What does this mean?

What are the Possible Causes of the DTC P0304 RAM?

Faulty Spark Plug #4
Clogged or faulty Fuel Injector #4
Faulty Ignition Coil #4
Fuel Injector #4 harness is open or shorted
Fuel Injector #4 circuit poor electrical connection
Ignition Coil #4 harness is open or shorted
Ignition Coil #4 circuit poor electrical connection
Insufficient cylinder 4 compression
Incorrect fuel pressure
Intake air leak

How to Fix the DTC P0304 RAM?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

The P0304 code means that cylinder 4 is misfiring or is randomly misfiring. Start by checking for intake leaks and if no leaks are found the next step is to replace the spark plugs on cylinder 4. If the problem persists more tests need to be done to diagnose the problem, see "Possible Causes".

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0304 RAM code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0304 RAM Code

1. What does the OBDII code P0304 mean on a RAM vehicle?

P0304 indicates a misfire has been detected in cylinder 4 of the engine.

2. What are the common symptoms of a P0304 code in a RAM?

Symptoms include rough idling, reduced engine performance, poor fuel economy, and sometimes a flashing Check Engine Light.

3. What causes a P0304 code to appear on a RAM?

Common causes include a faulty spark plug, ignition coil, fuel injector, vacuum leak, or low cylinder compression in cylinder 4.

4. Can driving with a P0304 code damage my RAM engine?

Yes, prolonged driving with a misfire can cause damage to the catalytic converter and other engine components.

5. How do you diagnose a P0304 code on a RAM?

Diagnosis typically involves inspecting the spark plug and ignition coil for cylinder 4, checking for vacuum leaks, testing fuel injectors, and performing a compression test.

6. Can a dirty fuel injector cause a P0304 code?

Yes, a clogged or malfunctioning fuel injector in cylinder 4 can lead to a misfire and trigger this code.

7. Is a bad spark plug the most common cause of a P0304 code in a RAM?

Yes, a worn or damaged spark plug is one of the most common causes of a cylinder 4 misfire.

8. How much does it cost to fix a P0304 code on a RAM?

Repair costs vary depending on the cause, but replacing a spark plug or ignition coil typically costs between $100 and $300, while more extensive repairs like fixing compression issues can be more expensive.

9. Can a vacuum leak trigger the P0304 code on a RAM?

Yes, a vacuum leak near cylinder 4 can disrupt the air-fuel mixture and cause a misfire.

10. What should I do if my RAM has a P0304 code?

Start by checking the spark plug and ignition components for cylinder 4. If those are fine, consult a mechanic for further diagnosis to avoid further engine damage.