AutoCodes – Mercedes-Benz – P0357 Mercedes-Benz

P0357 Mercedes-Benz Code - Ignition Coil 7 Primary/Secondary Circuit Malfunction

Quick Answer

The ignition system on the vehicle uses individual ignition coils for each cylinder. Common causes include Faulty Ignition Coil 7, Ignition Coil 7 harness is open or shorted, Ignition Coil 7 circuit poor electrical connection. 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: P0357 Mercedes-Benz indicates Ignition Coil 7 Primary/Secondary Circuit Malfunction.
Common causes: Common causes include Faulty Ignition Coil 7, Ignition Coil 7 harness is open or shorted, Ignition Coil 7 circuit poor electrical connection.
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 8,413

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0357 Mercedes-Benz Description

The ignition system on the vehicle uses individual ignition coils for each cylinder. The Engine Control Module (ECM) controls each ignition coil operation. The ECM sends a ON/OFF signal to energize the ignition coil to create a spark at the spark plug when a spark is required at the cylinder.

OBDII Code P0357 Mercedes-Benz - Ignition Coil 7 Primary/Secondary Circuit Malfunction - AutoCodes.com — P0357 Mercedes-Benz Code - Ignition Coil 7 Primary/Secondary Circuit Malfunction

What does this mean?

What are the Possible Causes of the DTC P0357 Mercedes-Benz?

Faulty Ignition Coil 7
Ignition Coil 7 harness is open or shorted
Ignition Coil 7 circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P0357 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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0357 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 P0357 Mercedes-Benz code?

Need more information on how to fix the P0357 Mercedes-Benz code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0357 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 P0357 Mercedes-Benz Code

1. What are the common symptoms of OBDII code P0357 in a Mercedes-Benz related to Ignition Coil 7 Primary/Secondary Circuit Malfunction?

Symptoms may include engine misfires, rough idle, lack of power, and illuminated check engine light.

2. What are the possible causes of OBDII code P0357 in a Mercedes-Benz?

Potential causes include a faulty ignition coil, damaged wiring or connectors, ECM issues, or a problem with the spark plug related to cylinder 7.

3. How can I diagnose the OBDII code P0357 in my Mercedes-Benz?

You can diagnose this code by using a diagnostic scanner to read the code, inspecting the ignition coil and related components, checking for loose connections, and performing a resistance test on the ignition coil.

4. Can I continue driving my Mercedes-Benz with OBDII code P0357 related to Ignition Coil 7 Primary/Secondary Circuit Malfunction?

It is not recommended to continue driving with this code as it can cause further damage to the engine and emission control system.

5. How can I repair OBDII code P0357 in my Mercedes-Benz?

The repair typically involves replacing the faulty ignition coil for cylinder 7, addressing any wiring or connector issues, and clearing the code with a diagnostic scanner.

6. Can a DIY enthusiast fix OBDII code P0357 in a Mercedes-Benz?

Yes, if you have the necessary tools and knowledge, you can attempt to fix this issue yourself. However, it is recommended to consult a professional if you are unsure.

7. Is it common for Ignition Coil 7 to fail in Mercedes-Benz vehicles?

While ignition coil failures can occur in any vehicle, it is not uncommon for them to fail in Mercedes-Benz vehicles, especially as they age.

8. Are there any preventive maintenance tips to avoid OBDII code P0357 in a Mercedes-Benz?

Regularly inspecting the ignition system, replacing spark plugs at recommended intervals, and using high-quality fuel can help prevent ignition coil issues.

9. How long does it typically take to repair OBDII code P0357 in a Mercedes-Benz?

The repair time can vary depending on the extent of the issue and the availability of parts, but it generally takes a few hours to complete the repair.

10. Will resetting the check engine light make OBDII code P0357 go away in a Mercedes-Benz?

Resetting the check engine light may temporarily make the light go away, but the underlying issue causing the code will still need to be diagnosed and repaired to prevent further problems.