P0252 Mercedes-Benz Code - Injection Pump Fuel Metering Control 'A' Range/Performance
Quick Answer
This fault code is stored in the Engine Control Module (ECM) when the system cannot correctly control the fuel pressure. Common causes include Faulty Fuel Pump, Fuel Pump harness is open or shorted, Fuel Pump 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
- P0252 Mercedes-Benz indicates Injection Pump Fuel Metering Control 'A' Range/Performance.
- Common causes
- Common causes include Faulty Fuel Pump, Fuel Pump harness is open or shorted, Fuel Pump 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.
Code P0252 Mercedes-Benz Description
Normally manufacturers will support data parameters for actual and desired fuel pressure.
A number of issues may cause this fault code to be set such as a faulty fuel rail pressure sensor, a mechanical fault with a fuel inlet metering valve could cause the valve to become stuck. An electrical fault such as an open circuit in the fuel inlet metering valve on a system with a normally closed valve will also cause this situation. A short circuit on the control wire of a normally open fuel pressure regulator will also cause this fault.
A fault in the fuel injector return system will cause the fuel pressure to be lower than expected. This causes fuel from the high-pressure circuit to be leaked back to the low-pressure circuit. A faulty maximum pressure relief valve will also cause this situation.
The high-pressure pump should also be tested to ensure it is capable of delivering the required volume of fuel.
What are the Possible Causes of the DTC P0252 Mercedes-Benz?
- Faulty Fuel Pump
- Fuel Pump harness is open or shorted
- Fuel Pump circuit poor electrical connection
- Faulty Engine Control Module (ECM)
How to Fix the DTC P0252 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 P0252 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.
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Frequently Asked Questions about P0252 Mercedes-Benz Code
1. What are common symptoms of the OBDII code P0252 in a Mercedes-Benz related to Injection Pump Fuel Metering Control 'A' Range/Performance?
- Common symptoms include hard starting, rough idling, loss of power, and potentially stalling while driving.
2. What are some possible causes of the P0252 code in a Mercedes-Benz?
- Potential causes include a faulty fuel injection pump, issues with the fuel pressure regulator, clogged fuel filters, or wiring harness problems.
3. How can I diagnose the P0252 code in my Mercedes-Benz?
- Diagnosis typically involves using a scan tool to read the code, checking the fuel system for any obvious issues, and testing the fuel injection pump and related components for proper function.
4. Can driving with the P0252 code in my Mercedes-Benz cause further damage?
- Continuing to drive with the P0252 code can potentially cause damage to the fuel system components and may lead to more severe performance issues over time.
5. How can I repair the P0252 code in my Mercedes-Benz?
- Repairing the P0252 code often involves replacing the faulty fuel injection pump, addressing any fuel pressure regulator issues, clearing out clogged fuel filters, or repairing wiring harness issues.
6. Is it safe to continue driving my Mercedes-Benz with the P0252 code present?
- It is not recommended to continue driving with the P0252 code as it can lead to poor engine performance and potential safety hazards while driving.
7. Will resetting the OBDII code P0252 in my Mercedes-Benz make the issue go away?
- Resetting the code may temporarily turn off the check engine light, but the underlying issue causing the P0252 code will still need to be diagnosed and repaired to prevent further problems.
8. Can a DIY enthusiast fix the P0252 code issue in a Mercedes-Benz?
- While some basic troubleshooting steps can be performed by a DIY enthusiast, diagnosing and repairing the P0252 code typically requires specialized tools and expertise, so it is recommended to consult a professional mechanic.
9. How much does it cost to repair the P0252 code in a Mercedes-Benz?
- The cost of repairing the P0252 code 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.
10. How can I prevent the P0252 code from occurring in my Mercedes-Benz in the future?
- Regular maintenance of the fuel system, including timely replacement of fuel filters and using quality fuel, can help prevent issues like the P0252 code from occurring in the future.
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