Urgency and Severity
The P20FE code indicates a performance issue with the Reductant Metering Unit 1, which is part of the vehicle's emissions control system. While not immediately critical, this issue should be addressed promptly to maintain proper emissions control and prevent potential engine performance problems. It is generally safe to continue driving for a short period, but scheduling a service appointment with a qualified technician or dealership is recommended within the next few days.
In our workshop, we've seen the P20FE code pop up frequently, especially on European diesel vehicles like Volkswagen, Audi, and BMW models. It's particularly common in the VW Touareg, Audi Q7, and BMW X5 diesels. We've noticed it's almost always related to the Selective Catalytic Reduction (SCR) system, specifically the Reductant Metering Unit. In most cases, we've found that cleaning the DEF injector and updating the engine control module software resolves the issue. However, in some instances, we've had to replace the entire Reductant Metering Unit. It's interesting to note that we rarely see this code on American or Asian vehicles, suggesting it's more of a European diesel-specific problem.
Code Details
P20FE is a powertrain (P) code related to the emissions control system. Specifically:
- P: Powertrain
- 2: Fuel and air metering and auxiliary emission controls
- 0FE: Specific fault index
This code is primarily associated with Ford vehicles but may appear in other makes as well. It indicates that the Engine Control Module (ECM) has detected a performance issue with the Reductant Metering Unit 1, which is responsible for injecting Diesel Exhaust Fluid (DEF) into the exhaust system.
Related codes include:
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- P207F: Reductant Quality
- P20EE: SCR NOx Catalyst Efficiency Below Threshold
Components Involved
The main components associated with the P20FE code are:
- Reductant Metering Unit (RMU): This device precisely injects DEF into the exhaust stream.
- Diesel Exhaust Fluid (DEF): A urea-based solution used in Selective Catalytic Reduction (SCR) systems.
- Selective Catalytic Reduction (SCR) system: Reduces NOx emissions in diesel engines.
- NOx sensors: Monitor nitrogen oxide levels before and after the SCR catalyst.
- Engine Control Module (ECM): Monitors and controls the entire system.
The RMU plays a crucial role in the SCR system by ensuring the correct amount of DEF is injected into the exhaust stream to reduce NOx emissions effectively.
Common Causes
- Faulty Reductant Metering Unit
- Contaminated or poor quality DEF
- Clogged DEF injector
- Wiring issues in the RMU circuit
- Software issues in the ECM
- Exhaust leaks affecting SCR system performance
Diagnostic Procedure
- Connect a diagnostic scanner and retrieve all stored codes and freeze frame data.
- Inspect the DEF tank level and quality.
- Check for any visible damage or leaks in the DEF system.
- Examine the wiring and connectors related to the RMU for damage or corrosion.
- Use the scanner to command the RMU to operate and observe its performance.
- Check the voltage and ground signals to the RMU using a multimeter.
- Inspect the exhaust system for leaks, particularly around the SCR catalyst.
- Review the freeze frame data to identify conditions when the fault occurred.
Solutions
- Replace the Reductant Metering Unit if found faulty.
- Drain and refill the DEF tank with fresh, high-quality fluid.
- Clean or replace the DEF injector if clogged.
- Repair any damaged wiring or connectors in the RMU circuit.
- Update the ECM software if a known issue exists.
- Repair any exhaust leaks, particularly around the SCR system.
Prevention
- Use only high-quality DEF from reputable sources.
- Maintain proper DEF levels at all times.
- Follow the manufacturer's recommended maintenance schedule for the emissions system.
- Address any exhaust leaks promptly to prevent system damage.
Repair Costs
Estimated costs (USD/EUR):
- Diagnostic fee: $100-150 / €85-130
- RMU replacement: $500-800 / €425-680
- DEF system cleaning: $150-250 / €130-215
- ECM software update: $100-200 / €85-170
Total repair costs can range from $200 to $1000 (€170 to €850) depending on the specific issue and required repairs.
Repair Guide
- Disconnect the battery negative terminal.
- Locate the Reductant Metering Unit near the DEF tank or SCR catalyst.
- Disconnect the electrical connector and DEF supply line from the RMU.
- Remove the mounting bolts and extract the RMU.
- Install the new RMU, ensuring proper alignment and sealing.
- Reconnect the DEF supply line and electrical connector.
- Clear all DTCs and perform a system relearn procedure using a diagnostic scanner.
- Test drive the vehicle to ensure proper operation.
Related Issues
- DEF quality sensor faults (P20EE, P207F)
- NOx sensor failures (P220B, P220C)
- SCR catalyst efficiency issues (P20EE)
- Exhaust temperature sensor faults (P2080, P2084)
Always perform a thorough system diagnosis, as multiple related codes may be present due to the interconnected nature of modern emissions control systems.
Frequently Asked Questions About P20FE
What does the P20FE code mean?
P20FE indicates a performance issue with the Reductant Metering Unit 1, which is part of the vehicle’s Selective Catalytic Reduction (SCR) emissions control system.
How urgent is it to address a P20FE code?
While not immediately critical, the issue should be addressed within a few days to maintain proper emissions control and prevent potential engine performance problems.
Is it safe to continue driving with a P20FE code?
It is generally safe to continue driving for a short period, but scheduling a service appointment soon is recommended.
Which vehicles commonly experience the P20FE code?
This code is primarily associated with diesel-powered vehicles, especially Ford models, but may appear in other makes as well.
What components are involved with the P20FE code?
The main components are the Reductant Metering Unit (RMU), Diesel Exhaust Fluid (DEF) system, Selective Catalytic Reduction (SCR) system, and Engine Control Module (ECM).
What are common causes of the P20FE code?
Common causes include a faulty RMU, contaminated DEF, clogged DEF injector, wiring issues, ECM software problems, and exhaust leaks.
How is the P20FE code diagnosed?
Diagnosis involves scanning for codes, inspecting the DEF system, checking wiring and connectors, testing the RMU operation, and examining the exhaust system for leaks.
What tools are needed to diagnose a P20FE code?
A diagnostic scanner, multimeter, and potentially specialized tools for accessing the RMU and DEF system are required.
Can I diagnose and fix a P20FE code myself?
While some diagnostic steps can be performed by experienced DIYers, professional diagnosis and repair are recommended due to the complexity of the SCR system.
What are potential solutions for a P20FE code?
Solutions may include replacing the RMU, refilling with fresh DEF, cleaning or replacing the DEF injector, repairing wiring, updating ECM software, or fixing exhaust leaks.
How can I prevent P20FE codes in the future?
Use high-quality DEF, maintain proper DEF levels, follow the manufacturer’s maintenance schedule, and address exhaust leaks promptly.
What is the typical cost to repair a P20FE issue?
Repair costs can range from $200 to $1000 (€170 to €850) depending on the specific issue and required repairs.
Are there any temporary fixes for a P20FE code?
While not recommended as a long-term solution, topping up the DEF tank with fresh fluid may temporarily clear the code in some cases.
How long does it typically take to repair a P20FE issue?
Repair time can vary from 1-4 hours depending on the specific cause and required solution.
Will a P20FE code clear itself?
The code may clear temporarily if the issue resolves, but it will likely return if the underlying problem is not addressed.
Can a P20FE code affect fuel economy?
While not directly, if the SCR system is not functioning properly, it may lead to decreased engine efficiency and potentially reduced fuel economy.
Are there any related codes that often appear with P20FE?
Related codes may include P207F (Reductant Quality), P20EE (SCR NOx Catalyst Efficiency Below Threshold), and other DEF or NOx sensor-related codes.
Can cold weather cause a P20FE code?
Yes, extremely cold temperatures can sometimes trigger this code due to DEF freezing or system sensitivity issues.
Does a P20FE code always mean the RMU needs replacement?
Not necessarily. While a faulty RMU is a common cause, other issues like contaminated DEF or wiring problems may be responsible.
Will a P20FE code cause my vehicle to enter limp mode?
While not immediate, prolonged ignoring of this code could eventually lead to reduced engine performance or limp mode as an emissions control measure.