P0173 Mercedes-Benz Code - Fuel Trim Malfunction Bank 2
Quick Answer
The P0173 code for a Mercedes-Benz indicates a fuel trim malfunction in Bank 2. Common causes include Vacuum leaks, Faulty oxygen sensor, Malfunctioning fuel injector. 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
- P0173 Mercedes-Benz indicates Fuel Trim Malfunction Bank 2.
- Common causes
- Common causes include Vacuum leaks, Faulty oxygen sensor, Malfunctioning fuel injector.
- 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 P0173 Mercedes-Benz Description
The P0173 code for a Mercedes-Benz indicates a fuel trim malfunction in Bank 2. The fuel trim is the adjustment made by the engine control module (ECM) to the air-fuel mixture being fed into the engine. In the case of Bank 2, this refers to the side of the engine that does not contain the number one cylinder. This code signifies that the ECM has detected that the fuel trim in Bank 2 is outside of the specified range, indicating a potential issue with the air-fuel mixture.
Common Causes of P0173 Mercedes-Benz
- Vacuum leaks
- Faulty oxygen sensor
- Malfunctioning fuel injector
- Clogged fuel filter
- Issue with the mass airflow sensor
Symptoms of P0173 Mercedes-Benz
- Decreased fuel economy
- Engine performance issues
- Rough idling or stalling
- Increased emissions
- Check engine light illuminated
How to Fix P0173 Mercedes-Benz
- Diagnose the specific cause of the fuel trim malfunction using a scan tool to read live data and pinpoint the issue.
- Repair or replace any faulty components such as vacuum lines, oxygen sensors, fuel injectors, fuel filters, or mass airflow sensors.
- Clear the diagnostic trouble codes from the ECM using the scan tool.
- Perform a test drive to ensure the issue has been resolved and that the fuel trim is now within the correct range.
- If the problem persists, further diagnostic procedures may be necessary to identify any underlying issues.
Cost to Fix P0173 Mercedes-Benz
The cost of repairing a P0173 code on a Mercedes-Benz can vary depending on the specific cause of the fuel trim malfunction and the cost of parts and labor. On average, the repair costs for this issue can range from $200 to $500. However, it's important to note that labor rates can vary significantly based on location, vehicle make and model, and the expertise of the repair shop. It's recommended to contact local auto repair shops for a more accurate estimate.
Tech Notes for P0173 Mercedes-Benz
When is the Code Detected?
- The amount of mixture ratio compensation is not correct
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Frequently Asked Questions about P0173 Mercedes-Benz Code
1. What does OBDII code P0173 for a Mercedes-Benz mean?
- OBDII code P0173 indicates a fuel trim malfunction on Bank 2 of the engine in a Mercedes-Benz vehicle.
2. What are the common symptoms of a P0173 code in a Mercedes-Benz?
- Common symptoms of a P0173 code in a Mercedes-Benz may include rough idling, decreased fuel efficiency, loss of power, and the illumination of the Check Engine light.
3. What are the possible causes of a P0173 code in a Mercedes-Benz?
- The potential causes of a P0173 code in a Mercedes-Benz include a vacuum leak, faulty oxygen sensor, clogged fuel filter, malfunctioning mass airflow sensor, or issues with the fuel injectors.
4. How can I diagnose a P0173 code in my Mercedes-Benz?
- Diagnosing a P0173 code in a Mercedes-Benz typically involves using an OBDII scanner to read the code, conducting a visual inspection for any obvious issues, checking for vacuum leaks, and testing the oxygen sensor and other related components.
5. Can I continue driving my Mercedes-Benz with a P0173 code?
- It is not recommended to drive your Mercedes-Benz with a P0173 code, as it can lead to poor engine performance and potential damage if left unresolved.
6. How can I repair a P0173 code in my Mercedes-Benz?
- Repairing a P0173 code in a Mercedes-Benz may involve fixing any vacuum leaks, replacing the oxygen sensor, cleaning or replacing the mass airflow sensor, inspecting and cleaning the fuel injectors, and ensuring the fuel system is in good condition.
7. Will resetting the OBDII code P0173 in my Mercedes-Benz make it go away permanently?
- Resetting the OBDII code P0173 in your Mercedes-Benz may temporarily turn off the Check Engine light, but if the underlying issue causing the code is not addressed, the code is likely to reappear.
8. How much does it typically cost to repair a P0173 code in a Mercedes-Benz?
- The cost of repairing a P0173 code in a Mercedes-Benz 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. Can a DIY enthusiast fix a P0173 code in a Mercedes-Benz?
- Depending on the DIY enthusiast's experience and tools, some may be able to address simpler causes of a P0173 code, such as replacing an oxygen sensor or cleaning a mass airflow sensor. However, more complex issues may require professional assistance.
10. How often should I check for a P0173 code in my Mercedes-Benz?
- It is recommended to regularly monitor your Mercedes-Benz for any signs of engine trouble, including checking for OBDII codes like P0173, especially if you notice any changes in the vehicle's performance or fuel efficiency.
Discuss the causes and fixes for P0173 Mercedes-Benz OBDII Code
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Check eng light illuminated. Scanned ECU=code P0170 Fuel trim bank 1, P0173Fuel trim bank 2. Changed MAF, reset ECU and almost immediately eng check light came back, ECU test again, same codes returned. Propose to look at PCV valve if there is one, where located, clean throttle body and butterfly valve. Air cleaner good, will do a visual again for any hoses loose, disconnected or damaged. Any additional info appreciated. If not fixed have to check O2 sensor.
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