P0173 Mercedes-Benz Code - Fuel Trim Malfunction Bank 2
Quick Answer
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. Common causes include Intake air leaks, Faulty front heated oxygen sensor, Ignition misfiring. 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 Intake air leaks, Faulty front heated oxygen sensor, Ignition misfiring.
- 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 P0173 Mercedes-Benz Description
In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the ECM judges the condition as the fuel injection system malfunction and light up the MIL (2 trip detection logic).
What are the Possible Causes of the DTC P0173 Mercedes-Benz?
- Intake air leaks
- Faulty front heated oxygen sensor
- Ignition misfiring
- Faulty fuel injectors
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Faulty Mass Air Flow (MAF) sensor
- Incorrect Positive Crankcase Ventilation (PCV) hose connection
How to Fix the DTC P0173 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.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0173 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 P0173 Mercedes-Benz code?
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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
-
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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