P2047 – Reductant Injector Circuit Open

Understanding the P2047 Engine Code: Causes, Diagnosis, and Repair

The P2047 is a diagnostic trouble code (DTC) that indicates a problem with the reductant injection valve circuit on bank 1, unit 1. This code is considered critical and should be addressed promptly to avoid potential damage to the exhaust system and other components. While it may be possible to drive short distances with this code present, it's best to have the issue diagnosed and repaired as soon as possible to prevent further issues.

About the P2047 Code

The P2047 code specifically points to an open circuit condition in the wiring for the reductant injection valve on bank 1, unit 1. This valve is a key component of the Selective Catalytic Reduction (SCR) system used on many modern diesel vehicles to reduce NOx emissions.

The reductant injection valve is responsible for spraying diesel exhaust fluid (DEF) into the exhaust stream, where it reacts with NOx and converts it into harmless nitrogen and water. If the valve or its control circuit malfunctions, it can prevent proper DEF injection, leading to increased emissions and potential damage to the SCR catalyst and other exhaust components.

While the P2047 code is a generic powertrain code, the exact configuration and location of the reductant injection valve may vary between different vehicle makes and models. However, the basic principles of operation and common causes of failure are generally the same across applications.

Common Causes

There are several potential causes that can trigger a P2047 code, including:

• Damaged or corroded wiring in the reductant injection valve circuit
• Faulty reductant injection valve (solenoid)
• Exhaust leaks upstream of the SCR catalyst
• Low DEF fluid level in the reservoir
• Issues with the SCR control module or programming errors

In some cases, other related DTCs may be stored along with P2047, such as codes related to the DEF tank temperature sensor, DEF quality sensor, or other SCR system components. It's important to diagnose and address any additional codes as well for a complete repair.

Diagnosing the Issue

To properly diagnose a P2047 code, you'll need a scan tool capable of reading powertrain DTCs, a digital multimeter (DMM), and a vehicle-specific service manual or wiring diagram. Follow these general steps to troubleshoot the issue:

1. Connect the scan tool and retrieve all stored codes and freeze frame data. Make note of any other codes present.

2. Visually inspect the wiring harness and connectors for the reductant injection valve. Look for any signs of damage, corrosion, or loose connections and repair as needed.

3. Using the DMM, test for proper voltage and ground signals at the valve connector. Refer to the service manual for the specific pinout and expected values, which may vary by application.

4. If the wiring checks out okay, test the resistance of the valve solenoid itself. Again, consult the service information for the proper specifications, but in general, the solenoid should have some resistance (not open) and read around 10-30 ohms.

5. Check for any signs of exhaust leaks before the SCR catalyst, as this can allow unmetered air to enter the system and throw off the reductant injection. Repair any leaks found.

6. If the valve, wiring, and exhaust all check out okay, there may be an issue with the SCR control module programming or hardware. In this case, more advanced diagnosis with a factory scan tool may be required.

Repairing the Problem

The specific repairs needed to address a P2047 code will depend on the root cause determined during diagnosis. Common fixes include:

• Repairing damaged wiring or connectors in the reductant injection valve circuit
• Replacing a faulty reductant injection valve/solenoid
• Repairing upstream exhaust leaks
• Updating the SCR control module software or replacing the unit if faulty

In terms of cost, repairing wiring issues may only be a few hundred dollars in parts and labor, while replacing a complete reductant injection valve assembly can range from $500-1500 or more depending on the vehicle. Exhaust repairs and SCR module replacement would likely fall somewhere in between.

For more detailed repair information and procedures, consult the factory service manual or a repair database like AllData or Mitchell 1 for your specific vehicle. Many of these resources include step-by-step guides and diagrams to help walk through the process.

Preventing P2047

To help prevent issues that can lead to a P2047 code in the future, consider the following:

• Maintain the DEF system properly, including regular fluid changes and keeping the reservoir filled
• Address any exhaust leaks promptly to prevent excess air from entering the SCR system
• Keep electrical connectors clean and protected from corrosion, especially those exposed to the elements
• Follow the manufacturer's recommended service intervals for the SCR system and related components

By staying on top of maintenance and addressing potential issues early, you can help avoid more serious and costly problems down the road.

Frequently Asked Questions About P2047

What is the P2047 engine code?

P2047 is a diagnostic trouble code (DTC) that indicates an open circuit condition in the wiring for the reductant injection valve on bank 1, unit 1. This valve is part of the Selective Catalytic Reduction (SCR) system used to reduce NOx emissions in diesel vehicles.

What does the code P2047 mean?

Code P2047 means that the powertrain control module (PCM) has detected an open circuit or lack of voltage in the control circuit for the reductant injection valve on bank 1, unit 1. This indicates a problem with the valve, its wiring, or the PCM itself.

How serious is a P2047 code?

A P2047 code should be considered a serious issue and addressed promptly. If left unresolved, it can lead to increased emissions, reduced engine performance, and potential damage to the SCR catalyst and other exhaust components.

Is it safe to drive with a P2047 code?

While it may be possible to drive short distances with a P2047 code present, it's not recommended. The SCR system may be disabled, leading to increased emissions and potential fines. It's best to have the issue diagnosed and repaired as soon as possible.

What are the common symptoms of a P2047 code?

Common symptoms of a P2047 code include:

• Illuminated check engine light
• Reduced engine performance
• Increased fuel consumption
• Rough idle or misfires
• Excessive black smoke from the exhaust

What are the common causes of a P2047 code?

Common causes of a P2047 code include:

• Faulty reductant injection valve
• Damaged or corroded wiring in the valve circuit
• Blown fuses or relays related to the SCR system
• Exhaust leaks before the SCR catalyst
• Low diesel exhaust fluid (DEF) level
• Issues with the SCR control module or PCM

How do you diagnose a P2047 code?

To diagnose a P2047 code:

1. Scan for codes and document freeze frame data
2. Visually inspect wiring and connectors
3. Test for proper voltage and ground at the valve
4. Check resistance of the valve solenoid
5. Inspect for exhaust leaks
6. Verify proper DEF level and quality
7. Check SCR control module for errors

What tools are needed to diagnose a P2047 code?

To properly diagnose a P2047 code, you'll need:

• An OBD-II scanner capable of reading generic and manufacturer-specific codes
• A digital multimeter for testing voltage, ground, and resistance
• A vehicle-specific service manual or wiring diagram
• Basic hand tools for accessing wiring and connectors

Can a P2047 code cause a vehicle to fail an emissions test?

Yes, a P2047 code will likely cause a vehicle to fail an emissions test. The SCR system is critical for reducing NOx emissions, and any faults that prevent it from functioning properly can lead to increased pollutants and an emissions test failure.

How much does it cost to repair a P2047 code?

The cost to repair a P2047 code can vary widely depending on the root cause and the specific vehicle. Minor issues like a loose connector or blown fuse may cost less than $100 to fix, while replacing a faulty injection valve or SCR control module could be $500-1500 or more.

Can a P2047 code be caused by low DEF fluid?

While low DEF fluid alone may not directly set a P2047 code, it can contribute to issues that lead to this code. If the DEF level is too low, the SCR system may not be able to properly inject the fluid, leading to increased emissions and potential catalyst damage.

How often should the DEF fluid be topped off to prevent a P2047 code?

The frequency of DEF refills varies by vehicle, but most manufacturers recommend checking the level at every oil change and topping it off as needed. A typical tank of DEF can last anywhere from 3,000-10,000 miles depending on driving conditions.

Can a P2047 code be caused by a bad NOx sensor?

While a faulty NOx sensor alone may not set a P2047 code, it can lead to improper DEF dosing and SCR system malfunctions that could potentially trigger this code. Any issues with sensors related to the SCR system should be addressed as part of a thorough diagnosis.

Will clearing a P2047 code fix the problem?

No, simply clearing a P2047 code will not fix the underlying problem. The code will likely reappear after some driving if the root cause, such as a faulty injection valve or wiring issue, is not repaired. Proper diagnosis and repair are needed to resolve the issue.

Can a software update fix a P2047 code?

In some cases, a software update may resolve a P2047 code if it's caused by a programming error in the PCM or SCR control module. However, software alone cannot fix physical issues like a faulty valve or damaged wiring. A proper diagnosis is needed to determine the root cause.

Can a P2047 code be caused by using the wrong type of DEF fluid?

Using the wrong type of DEF fluid, such as agricultural-grade urea or an off-brand solution, can definitely lead to SCR system issues and potentially set a P2047 code. It's important to use only API-certified DEF fluid that meets ISO 22241 specifications to avoid problems.

How do you test the reductant injection valve wiring for a P2047 code?

To test the reductant injection valve wiring:

1. Disconnect the valve and check for voltage at the harness
2. Test for continuity between the valve connector and PCM
3. Check for continuity between the valve and ground
4. Test the resistance of the valve solenoid
   Refer to a wiring diagram and service manual for specifications.

Can a P2047 code be caused by a clogged DEF injector?

Yes, a clogged DEF injector can set a P2047 code. If the injector is obstructed by crystallized DEF or other contaminants, it may not be able to spray fluid properly, leading to an open circuit condition. Cleaning or replacing the injector may be necessary.

What other codes may be present along with a P2047 code?

Other codes that may be present along with a P2047 include:

• P20EE – SCR NOx Catalyst Efficiency Below Threshold
• P2BAE – Reductant Pressure Too Low
• P20E8 – Reductant Pressure Too High
• P2BAF – DEF Consumption Too High
• P2BA3 – Reductant Level Sensor Circuit Range/Performance
  These codes can help pinpoint the root cause of the issue.

What should be done after repairing the cause of a P2047 code?

After repairing the cause of a P2047 code:

1. Clear the code using a scan tool
2. Drive the vehicle to allow the SCR system monitors to run
3. Recheck for any pending or active codes
4. Verify the repair by monitoring live data and ensuring proper operation
5. In some cases, a dealer may need to perform a forced DPF regen or SCR adaptation reset using a factory scan tool