Engine-CodesMercedes-Benz – P0382 Mercedes-Benz

P0382 Mercedes-Benz Code - Glow Plug/Heater Circuit 'B' Malfunction

Quick Answer

The P0382 diagnostic trouble code (DTC) for Mercedes-Benz vehicles refers to a Glow Plug/Heater Circuit 'B' Malfunction. Common causes include Faulty glow plug 'B', Damaged or corroded wiring in the glow plug circuit, Defective glow plug relay. 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
P0382 Mercedes-Benz indicates Glow Plug/Heater Circuit 'B' Malfunction.
Common causes
Common causes include Faulty glow plug 'B', Damaged or corroded wiring in the glow plug circuit, Defective glow plug relay.
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.
Table of contents Created and updated by William Orellana on Sep 07, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P0382 Mercedes-Benz Description

The P0382 diagnostic trouble code (DTC) for Mercedes-Benz vehicles refers to a Glow Plug/Heater Circuit 'B' Malfunction. Glow plugs are essential components in diesel engines, as they help preheat the combustion chamber to facilitate easier starting in cold weather conditions. When the engine is cold, glow plugs heat up to ensure proper ignition of the fuel-air mixture. In this case, the code specifically points to a malfunction in the circuit related to glow plug 'B'.

OBDII Code P0382 Mercedes-Benz - Glow Plug/Heater Circuit 'B' Malfunction
P0382 Mercedes-Benz Code - Glow Plug/Heater Circuit 'B' Malfunction

Common Causes of P0382 Mercedes-Benz

  1. Faulty glow plug 'B'.
  2. Damaged or corroded wiring in the glow plug circuit.
  3. Defective glow plug relay.
  4. Malfunctioning engine control module (ECM).
  5. Poor electrical connections in the circuit.

Symptoms of P0382 Mercedes-Benz

  1. Difficulty starting the engine, especially in cold weather.
  2. Rough idle or misfires upon startup.
  3. Decreased fuel efficiency.
  4. Illumination of the check engine light on the dashboard.
  5. Increased exhaust emissions.

How to Fix P0382 Mercedes-Benz

  1. Begin by diagnosing the specific cause of the Glow Plug/Heater Circuit 'B' Malfunction using a diagnostic scanner.
  2. Inspect the glow plug 'B' for functionality and replace it if necessary.
  3. Check the wiring and connections in the glow plug circuit for any damage or corrosion, repairing or replacing as needed.
  4. Test the glow plug relay and ECM for proper operation, replacing them if found to be faulty.
  5. Clear the DTC from the vehicle's computer system and test the vehicle to ensure the issue has been resolved.

Cost to Fix P0382 Mercedes-Benz

The typical repair costs for addressing a Glow Plug/Heater Circuit 'B' Malfunction in a Mercedes-Benz can range from $200 to $500, including parts and labor. However, it is important to note that prices can vary depending on the specific diagnosis time and labor rates at auto repair shops. Rates may be higher at dealerships or in metropolitan areas, while independent shops often offer more affordable options. It is advisable to obtain quotes from local shops for a more accurate estimate.

When is the Code Detected?

- The glow plugs are commanded OFF and the glow plug feedback is more than 2 volts. or
- The glow plugs are commanded on and the glow plug feedback is not between 5 volts and 6.2 volts.

Need more information about the P0382 Mercedes-Benz code?

Need more information on how to fix the P0382 Mercedes-Benz code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0382 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 P0382 Mercedes-Benz Code

What does OBDII code P0382 mean for a Mercedes-Benz?

P0382 indicates a malfunction in the Glow Plug/Heater Circuit 'B,' which affects the preheating system needed for diesel engine starts.

What are the common symptoms of code P0382 in a Mercedes-Benz?

Symptoms include difficulty starting the engine, rough idling, poor fuel efficiency, and potentially a check engine light.

What causes the P0382 code on a Mercedes-Benz?

Common causes include faulty glow plugs, damaged glow plug control module, wiring issues, or corroded electrical connections in the circuit.

How can I diagnose the P0382 code on a Mercedes-Benz?

Use an OBDII scanner to confirm the code, then inspect the glow plugs, wiring, control module, and connectors for damage or corrosion.

Can I still drive my Mercedes-Benz with the P0382 code?

While the car may still run, prolonged driving with this code can lead to cold start issues and potential damage to the engine. It’s best to address it promptly.

How do I fix the P0382 code on a Mercedes-Benz?

Repairs may include replacing faulty glow plugs, repairing damaged wiring, cleaning corroded connectors, or replacing the glow plug control module.

How much does it cost to repair the P0382 code on a Mercedes-Benz?

The repair cost varies but typically ranges from $200 to $500, depending on whether glow plugs or the control module need replacement.

Can the P0382 code cause long-term damage to my Mercedes-Benz?

If ignored, the code can lead to harder starts in cold weather and strain on the engine, potentially causing more expensive repairs over time.

What tools do I need to fix the P0382 code on a Mercedes-Benz?

You’ll need an OBDII scanner, a multimeter, basic hand tools, and possibly replacement glow plugs or a control module.

Does the P0382 code affect all Mercedes-Benz diesel models?

The P0382 code is specific to vehicles with diesel engines and may appear on various Mercedes-Benz models with glow plug systems.

Discuss the causes and fixes for P0382 Mercedes-Benz OBDII Code

Code P0382 Mercedes-Benz comments

No comments found for this page.