The P2059 trouble code is a diagnostic trouble code (DTC) that indicates an issue with the Reductant Injection Air Pump Control Circuit/Open. This code is primarily associated with diesel engines equipped with selective catalytic reduction (SCR) systems, which are designed to reduce nitrogen oxide (NOx) emissions. When the powertrain control module (PCM) detects an open circuit in the control circuit for the reductant injection air pump, it triggers this code. Ignoring this code can lead to reduced engine performance and increased emissions, making it crucial for vehicle owners and DIY mechanics to address it promptly.
| P2059 Code Meaning | P2059 Code Common Causes |
|---|---|
| Reductant Injection Air Pump Control Circuit/Open | Open or shorted wiring in the reductant injection air pump control circuit |
| Faulty reductant injection air pump control module | Defective reductant injection air pump |
| Corrosion or water intrusion in electrical connectors | Incorrect installation of the reductant injection air pump or its components |
Symptoms of P2059
The symptoms associated with the P2059 trouble code can vary but generally include:
- Check Engine Light: The most common symptom is illumination of the check engine light on the dashboard.
- Reduced Engine Performance: Drivers may notice a decrease in engine power and responsiveness.
- Increased Emissions: The vehicle may produce higher levels of NOx emissions, potentially leading to failed emissions tests.
- Poor Fuel Efficiency: A malfunctioning SCR system can result in decreased fuel economy.
- Excessive Exhaust Smoke: There may be visible black smoke from the exhaust, indicating incomplete combustion.
Technical Explanation
The P2059 code specifically relates to the reductant injection air pump, which is part of the SCR system used in modern diesel engines. This system injects a urea-based solution (diesel exhaust fluid, or DEF) into the exhaust stream to convert harmful NOx gases into harmless nitrogen and water vapor. The air pump is responsible for supplying compressed air to assist in this process. When there is an open circuit in the control system, it prevents the pump from functioning correctly, leading to increased emissions and potential damage to the catalytic converter if not addressed.
Step-by-Step Diagnosis
Diagnosing a P2059 trouble code involves several steps:
- Use a Diagnostic Scanner: Connect an OBD-II scanner to retrieve stored codes and freeze frame data. Document all codes present as they may indicate related issues.
- Inspect Wiring and Connectors: Check for any visible damage, corrosion, or loose connections in the wiring harness leading to the reductant injection air pump. Pay special attention to areas prone to moisture intrusion.
- Test the Reductant Injection Air Pump: Using a digital volt/ohmmeter (DVOM), test the resistance and functionality of the air pump. Ensure it operates within manufacturer specifications.
- Check Control Module Functionality: Verify that the reductant injection air pump control module is functioning properly. If necessary, replace it based on diagnostic results.
- Inspect SCR System for Leaks: Activate the SCR system and inspect for any leaks in the DEF lines or connections that could affect pressure readings.
- Clear Codes and Test Drive: After repairs are made, clear any stored codes and take the vehicle for a test drive to see if the P2059 code returns.
Solution Methods
To resolve a P2059 trouble code, consider these solution methods:
- Repair or Replace Damaged Wiring: If any wiring is found to be damaged or corroded, repair or replace it as necessary.
- Replace Faulty Components: If testing reveals that either the reductant injection air pump or its control module is defective, replace these components.
- Clean or Replace Connectors: Ensure all electrical connectors are clean and free from corrosion; replace any that are beyond repair.
- Verify Proper Installation: Check that all components of the SCR system are installed correctly according to manufacturer specifications.
Cost Estimates
The cost of diagnosing and repairing a P2059 trouble code can vary widely based on several factors:
- Diagnostic Fees: Expect to pay between $100 and $150 for diagnostic services at a shop.
- Parts Costs:
- Reductant Injection Air Pump: $300 – $600
- Control Module: $200 – $400
- Wiring Harness Repair Kits: $50 – $150
- Labor Costs: Labor rates typically range from $75 to $150 per hour, depending on your location and shop rates.
Overall, total repair costs can range from $500 to over $1,200 depending on parts needed and labor involved.
Warnings and Recommendations
- Professional Assistance Recommended: While DIY mechanics can tackle many repairs, complex electrical issues may require professional expertise. If you are unsure about any step in diagnosing or repairing this issue, consult with a certified mechanic.
- Regular Maintenance Checks: To prevent future issues related to DTCs like P2059, conduct regular maintenance checks on your vehicle’s SCR system and keep an eye out for warning signs such as unusual engine behavior or changes in performance.
- Use Quality Parts: Always use OEM or high-quality aftermarket parts when replacing components associated with your vehicle’s emission systems to ensure proper operation and longevity.
Frequently Asked Questions About P2059
- What does error code P2059 mean?
P2059 indicates an open circuit in the reductant injection air pump control circuit, affecting emissions control. - How serious is code P2059?
This code should be addressed promptly as it can lead to increased emissions and potential damage to your vehicle’s SCR system. - Can I drive my car with a P2059 code?
While it may be possible to drive short distances, it’s not recommended as it can worsen emissions issues. - What vehicles are affected by P2059?
This code applies to many OBD-II compliant vehicles, particularly those with diesel engines using SCR technology. - How do I clear a P2059 code?
You can clear this code using an OBD-II scanner after addressing any underlying issues. - Will replacing parts always fix P2059?
No; thorough diagnostics are essential because multiple issues can trigger this code. - What tools do I need to diagnose P2059?
A diagnostic scanner and a digital volt/ohmmeter (DVOM) are essential for accurate diagnosis. - Is it safe to ignore error code P2059?
No; ignoring this code can lead to significant engine performance issues and increased emissions.
In conclusion, understanding and addressing trouble codes like P2059 is crucial for maintaining your vehicle’s performance and compliance with emission standards. By following systematic diagnostic steps and utilizing appropriate repair methods, vehicle owners can effectively manage this issue while ensuring their vehicles run smoothly.