AutoCodes – Mercedes-Benz – P0242 Mercedes-Benz

P0242 Mercedes-Benz Code - Turbocharger/Supercharger Boost Sensor 'B' Circuit High

Quick Answer

The boost pressure sensor responds to pressure changes in the intake manifold. Common causes include Boost pressure sensor harness is open or shorted, Boost pressure sensor circuit poor electrical connection, Faulty boost pressure sensor. 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: P0242 Mercedes-Benz indicates Turbocharger/Supercharger Boost Sensor 'B' Circuit High.
Common causes: Common causes include Boost pressure sensor harness is open or shorted, Boost pressure sensor circuit poor electrical connection, Faulty boost pressure sensor.
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 6,662

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 14, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0242 Mercedes-Benz Description

The boost pressure sensor responds to pressure changes in the intake manifold. This pressure is created by the turbocharger and changes with accelerator pedal position (APP) and engine speed. The Engine Control Module (ECM) uses this information to assist in diagnosis of the barometric pressure (BARO) sensor and to provide engine overboost protection. The boost pressure sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. The Engine Control Module (ECM) supplies 5 volts to the boost pressure sensor on the 5-volt reference 2 circuit, and provides a ground on a low reference circuit. The boost pressure sensor provides a signal to the ECM on a signal circuit relative to the pressure changes. The ECM monitors the boost pressure sensor signal for voltage outside of the normal range. The ECM calculates a predicted value for the boost pressure sensor. The ECM then compares the predicted value to the actual signal.

OBDII Code P0242 Mercedes-Benz - Turbocharger/Supercharger Boost Sensor 'B' Circuit High - AutoCodes.com — P0242 Mercedes-Benz Code - Turbocharger/Supercharger Boost Sensor 'B' Circuit High

What does this mean?

What are the Possible Causes of the DTC P0242 Mercedes-Benz?

Boost pressure sensor harness is open or shorted
Boost pressure sensor circuit poor electrical connection
Faulty boost pressure sensor
Faulty Turbo/Super Charger
Engine over temperature
Ignition misfire exceeds the calibrated threshold
Faulty Knock sensor (KS)

How to Fix the DTC P0242 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 P0242 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 P0242 Mercedes-Benz 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 P0242 Mercedes-Benz Code

1. What are the common symptoms of OBDII code P0242 in a Mercedes-Benz related to the Turbocharger/Supercharger Boost Sensor 'B' Circuit High?

- Common symptoms include reduced engine performance, potential turbocharger or supercharger issues, and the illumination of the Check Engine light.

2. What are the possible causes of OBDII code P0242 in a Mercedes-Benz?

- Possible causes may include a faulty boost sensor, wiring issues in the boost sensor circuit, a malfunctioning turbocharger or supercharger, or an ECM (Engine Control Module) problem.

3. How can I diagnose the Turbocharger/Supercharger Boost Sensor 'B' Circuit High issue in my Mercedes-Benz?

- Diagnosis typically involves using an OBDII scanner to retrieve the specific fault code, inspecting the boost sensor and its wiring for any visible damage or corrosion, and testing the sensor for proper functionality.

4. Can I continue driving my Mercedes-Benz with OBDII code P0242 present?

- It is not recommended to continue driving with this code as it can lead to further damage to the turbocharger or supercharger system and may result in decreased engine performance and efficiency.

5. How can I repair OBDII code P0242 in my Mercedes-Benz?

- Repair options may include replacing the boost sensor, repairing any damaged wiring or connections in the boost sensor circuit, addressing any turbocharger or supercharger issues, or resetting the ECM after fixing the problem.

6. Is it possible to reset the Check Engine light after fixing OBDII code P0242 in my Mercedes-Benz?

- Yes, the Check Engine light can be reset using an OBDII scanner or by disconnecting the car's battery for a few minutes to clear the fault code and extinguish the light.

7. Are there any maintenance tips to prevent OBDII code P0242 from occurring in my Mercedes-Benz?

- Regularly inspecting and maintaining the turbocharger or supercharger system, checking the boost sensor and its wiring for any signs of wear or damage, and ensuring proper engine performance can help prevent this issue.

8. Can a DIY enthusiast fix OBDII code P0242 in a Mercedes-Benz?

- While some aspects of diagnosing and repairing this code can be done by a DIY enthusiast, it is recommended to consult a qualified mechanic or technician for accurate diagnosis and proper repair to avoid further complications.

9. How long does it typically take to repair OBDII code P0242 in a Mercedes-Benz?

- The repair time can vary depending on the exact cause of the issue, but it may take a few hours to a full day to diagnose, repair, and reset the system to clear the fault code.

10. Will fixing OBDII code P0242 improve the overall performance of my Mercedes-Benz?

- Yes, resolving this code can help restore the proper functioning of the turbocharger or supercharger system, leading to improved engine performance, fuel efficiency, and overall driving experience.