AutoCodes – Mercedes-Benz – P0278 Mercedes-Benz

P0278 Mercedes-Benz Code - Cylinder 6 Contribution/Balance Fault

Quick Answer

Code P0278 is triggered when the Engine Control Module (ECM) detects that the acceleration rate of the crankshaft for Cylinder 6 was less than a calibrated amount. Common causes include Dirty Fuel Injector 6, Faulty Fuel Injector 6, Plugged Fuel Injector 6. 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: P0278 Mercedes-Benz indicates Cylinder 6 Contribution/Balance Fault.
Common causes: Common causes include Dirty Fuel Injector 6, Faulty Fuel Injector 6, Plugged Fuel Injector 6.
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 9,596

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 Jun 02, 2022

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0278 Mercedes-Benz Description

Code P0278 is triggered when the Engine Control Module (ECM) detects that the acceleration rate of the crankshaft for Cylinder 6 was less than a calibrated amount. During normal conditions, the ECM turns the Fuel Injectors ON and OFF in the Fuel Injection System.

OBDII Code P0278 Mercedes-Benz - Cylinder 6 Contribution/Balance Fault - AutoCodes.com — P0278 Mercedes-Benz Code - Cylinder 6 Contribution/Balance Fault

What does this mean?

What are the Possible Causes of the DTC P0278 Mercedes-Benz?

Dirty Fuel Injector 6
Faulty Fuel Injector 6
Plugged Fuel Injector 6
Fuel injector 6 harness is open or shorted
Fuel injector 6 circuit poor electrical connection

How to Fix the DTC P0278 Mercedes-Benz?

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

Clogged or partially clogged fuel injector can cause this code. Start by performing an injector flush before replacing the injector.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0278 Mercedes-Benz 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.

Need more information about the P0278 Mercedes-Benz code?

Need more information on how to fix the P0278 Mercedes-Benz code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0278 Mercedes-Benz code diagnosed by a professional: Find a repair shop in your area

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 P0278 Mercedes-Benz Code

1. What are the common symptoms of OBDII code P0278 on a Mercedes-Benz?

- Common symptoms include rough idling, reduced engine performance, misfires, and potentially increased fuel consumption.

2. What does the OBDII code P0278 for a Mercedes-Benz indicate?

- The code P0278 specifically points to a Cylinder 6 Contribution/Balance Fault, indicating an issue with the performance of the number 6 cylinder in the engine.

3. What are the possible causes of a Cylinder 6 Contribution/Balance Fault on a Mercedes-Benz?

- Potential causes include a faulty fuel injector, fuel delivery issues, ignition problems, vacuum leaks, or mechanical issues within the cylinder itself.

4. How can I diagnose the source of the Cylinder 6 Contribution/Balance Fault on my Mercedes-Benz?

- Diagnosing the issue may involve conducting a cylinder balance test, checking the fuel injector for proper operation, inspecting ignition components, and performing a compression test on the number 6 cylinder.

5. Can driving with OBDII code P0278 on a Mercedes-Benz cause further damage?

- Continuing to drive with a Cylinder 6 Contribution/Balance Fault can potentially cause damage to the catalytic converter, oxygen sensors, or other engine components over time.

6. Is it safe to continue driving my Mercedes-Benz with code P0278 present?

- It is not recommended to drive the vehicle with this fault code present, as it can lead to poor engine performance and potential damage if left unresolved.

7. How can I repair OBDII code P0278 on my Mercedes-Benz?

- Repair options may include replacing the faulty fuel injector, addressing fuel delivery issues, fixing ignition problems, repairing vacuum leaks, or resolving any mechanical issues within the cylinder.

8. Are there any specific maintenance tips to prevent OBDII code P0278 on a Mercedes-Benz?

- Regularly servicing the fuel system, ensuring proper ignition system maintenance, and promptly addressing any engine performance issues can help prevent the occurrence of this fault code.

9. Can a DIY enthusiast fix OBDII code P0278 on a Mercedes-Benz?

- While some aspects of diagnosing and repairing the issue may be possible for experienced DIYers, resolving a Cylinder 6 Contribution/Balance Fault often requires specialized tools and expertise best left to professional technicians.

10. How much can I expect to pay for repairing OBDII code P0278 on a Mercedes-Benz?

- The cost of repairing this fault code can vary depending on the underlying issue, but it may involve expenses for parts replacement, labor costs, and diagnostic fees, potentially ranging from a few hundred to over a thousand dollars.