AutoCodes – Mercedes-Benz – P0320 Mercedes-Benz

P0320 Mercedes-Benz Code - Ignition/Distributor Engine Speed Input Circuit

Quick Answer

Ignition failure sensor is used to check whether the spark ignition is occurred correctly or not and also used to tachometer drive. Common causes include Faulty Ignition/Distributor engine speed sensor, Faulty Crankshaft Position sensor, Ignition/Distributor engine speed sensor harness is open or shorted. 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: P0320 Mercedes-Benz indicates Ignition/Distributor Engine Speed Input Circuit.
Common causes: Common causes include Faulty Ignition/Distributor engine speed sensor, Faulty Crankshaft Position sensor, Ignition/Distributor engine speed sensor harness is open or shorted.
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 9,053

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 Apr 16, 2019

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0320 Mercedes-Benz Description

Ignition failure sensor is used to check whether the spark ignition is occurred correctly or not and also used to tachometer drive. The sensor monitors the voltage difference between a resistance which is on the battery circuit for ignition coil. When the ignition coil works properly, the electric current through the resistance is detected as voltage drop. This is confirmed for every ignition event with the crankshaft sensor and the camshaft sensor. If Engine Control Module (ECM) detects a malfunction, no ignition is possible, so the engine would not start. If there is no ignition signal for a predetermined cycle for one or two ignition coils, an ignition coil circuit failure exists.

OBDII Code P0320 Mercedes-Benz - Ignition/Distributor Engine Speed Input Circuit - AutoCodes.com — P0320 Mercedes-Benz Code - Ignition/Distributor Engine Speed Input Circuit

What does this mean?

What are the Possible Causes of the DTC P0320 Mercedes-Benz?

Faulty Ignition/Distributor engine speed sensor
Faulty Crankshaft Position sensor
Ignition/Distributor engine speed sensor harness is open or shorted
Ignition/Distributor engine speed sensor circuit poor electrical connection
Low battery charge
Faulty Engine Control Module (ECM)

How to Fix the DTC P0320 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 P0320 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 P0320 Mercedes-Benz code?

Need more information on how to fix the P0320 Mercedes-Benz code? Get Access to Factory Service Manuals

Need Help with the Code?

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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 P0320 Mercedes-Benz Code

1. What does the OBDII code P0320 mean for a Mercedes-Benz?

P0320 indicates a problem with the Ignition/Distributor Engine Speed Input Circuit, which monitors engine speed and helps the ECU manage ignition timing and fuel delivery.

2. What are the common symptoms of the P0320 code in a Mercedes-Benz?

Symptoms may include engine stalling, difficulty starting, rough idling, reduced power, and an illuminated Check Engine Light.

3. What causes the P0320 code to appear on a Mercedes-Benz?

Common causes include a faulty crankshaft position sensor, damaged wiring or connectors in the circuit, a malfunctioning ignition module, or issues with the PCM/ECU.

4. Can a bad crankshaft position sensor trigger the P0320 code?

Yes, a faulty or failing crankshaft position sensor is one of the most common causes of the P0320 code.

5. Is it safe to drive a Mercedes-Benz with the P0320 code?

Driving with the P0320 code is not recommended, as it can lead to stalling or other safety issues, especially if the engine speed signal is lost while driving.

6. How is the P0320 code diagnosed in a Mercedes-Benz?

A mechanic will use an OBDII scanner to retrieve the code, inspect the crankshaft position sensor, ignition system, and related wiring, and test the components for proper functionality.

7. How can I fix the P0320 code on my Mercedes-Benz?

Repairs may include replacing the crankshaft position sensor, repairing or replacing damaged wiring, checking the ignition module, or reprogramming the ECU if needed.

8. Can a loose or corroded connector cause the P0320 code?

Yes, loose, corroded, or damaged connectors in the engine speed input circuit can disrupt the signal and trigger the P0320 code.

9. How much does it cost to repair the P0320 code on a Mercedes-Benz?

Repair costs vary but typically range from $100 to $400, depending on whether the crankshaft position sensor, wiring, or other components need replacement.

10. Can a faulty ECU cause the P0320 code in a Mercedes-Benz?

While rare, a malfunctioning or damaged ECU can cause the P0320 code if it fails to process the engine speed input signal correctly.