AutoCodes – Mercedes-Benz – P2520 Mercedes-Benz

P2520 Mercedes-Benz Code - A/C Request 'A' Circuit Low

Quick Answer

The Powertrain Control Module (PCM) monitors the refrigerant pressure through the Air Condition (A/C) Pressure Sensor. Common causes include Low refrigerant, Too much refrigerant, Faulty Low Side Pressure Sensor. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

What it means: P2520 Mercedes-Benz indicates A/C Request 'A' Circuit Low.
Common causes: Common causes include Low refrigerant, Too much refrigerant, Faulty Low Side Pressure Sensor.
Severity: Low - monitor the vehicle and repair when practical.
Can I drive?: The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

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Code Popularity 6,245

How popular is this code, among other codes? Low

Repair Importance Level

Low (Monitor) (1 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jan 17, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P2520 Mercedes-Benz Description

The Powertrain Control Module (PCM) monitors the refrigerant pressure through the Air Condition (A/C) Pressure Sensor. The PCM supplies a 5V reference and a low reference to the sensor. Changes in the A/C refrigerant pressure causes the sensor signal to the PCM to vary. When the pressure is high, the signal is high. When the pressure is low, the signal is low. The PCM sets the OBII code when the signal from the sensor is out of factory specifications.

OBDII Code P2520 Mercedes-Benz - A/C Request 'A' Circuit Low - AutoCodes.com — P2520 Mercedes-Benz Code - A/C Request 'A' Circuit Low

What does this mean?

What are the Possible Causes of the DTC P2520 Mercedes-Benz?

Low refrigerant
Too much refrigerant
Faulty Low Side Pressure Sensor
Low Side Pressure Sensor harness is open or shorted
Low Side Pressure Sensor circuit poor electrical connection

How to Fix the DTC P2520 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 P2520 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 P2520 Mercedes-Benz code?

Need more information on how to fix the P2520 Mercedes-Benz code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P2520 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 P2520 Mercedes-Benz Code

1. What are the common symptoms of OBDII code P2520 in a Mercedes-Benz related to the A/C Request 'A' Circuit Low?

- Common symptoms include the air conditioning system not working properly, lack of cool air, and potential issues with climate control.

2. What are the possible causes of OBDII code P2520 (A/C Request 'A' Circuit Low) in a Mercedes-Benz?

- The code may be triggered by a faulty A/C compressor, damaged wiring or connectors, a malfunctioning AC control module, or low refrigerant levels.

3. How can I diagnose the A/C Request 'A' Circuit Low issue in my Mercedes-Benz?

- A thorough inspection of the A/C system, checking for damaged wiring or connectors, testing the A/C compressor, and using an OBDII scanner to read the specific fault codes can help diagnose the problem.

4. Can I continue driving my Mercedes-Benz with the P2520 code (A/C Request 'A' Circuit Low) present?

- It is not recommended to drive your vehicle with this code present, as it can lead to further damage to the A/C system and potentially affect the overall performance of the vehicle.

5. How can I repair the A/C Request 'A' Circuit Low issue in my Mercedes-Benz?

- Repair may involve replacing the A/C compressor, repairing or replacing damaged wiring, checking and refilling refrigerant levels, or resetting the AC control module.

6. Is it possible to reset the OBDII code P2520 related to the A/C Request 'A' Circuit Low in a Mercedes-Benz?

- Resetting the code can be done using an OBDII scanner after the underlying issue has been identified and resolved. However, the code may reappear if the root cause is not properly addressed.

7. Can a DIY enthusiast fix the OBDII code P2520 (A/C Request 'A' Circuit Low) issue in a Mercedes-Benz?

- While some basic troubleshooting and inspections can be done by a DIY enthusiast, diagnosing and repairing complex A/C system issues may require professional expertise and specialized tools.

8. How much does it typically cost to repair the A/C Request 'A' Circuit Low issue in a Mercedes-Benz?

- The cost of repair can vary depending on the specific cause of the issue, but it may range from a few hundred to over a thousand dollars, including parts and labor.

9. Will fixing the P2520 code related to the A/C Request 'A' Circuit Low improve the overall performance of my Mercedes-Benz?

- Yes, resolving the A/C system issue indicated by the code can help restore proper functioning of the air conditioning system, improve comfort while driving, and prevent potential damage to other components.

10. Are there any preventive maintenance tips to avoid triggering the OBDII code P2520 in a Mercedes-Benz?

- Regularly servicing the A/C system, checking refrigerant levels, inspecting wiring for damage, and addressing any unusual noises or performance issues promptly can help prevent the occurrence of this code.