The P202D: Reductant Leakage code refers to a detected leak in the reductant (DEF/AdBlue) system. This can be caused by physical leaks from the reductant lines, faulty connections, or pressure issues in the system.
P202D – Quick Overview
Code | Information |
---|---|
Meaning | P202D: Reductant Leakage |
Is it serious? | Yes, a reductant leakage can impair the vehicle’s ability to reduce NOx emissions, leading to higher emissions and potentially reduced engine performance. |
Possible causes | – Reductant leakage from the system – Faulty reductant lines or connections – System pressure issues |
How to diagnose? | – Inspect the reductant system for leaks – Check connections and lines – Verify system pressure |
P202D Meaning
The P202D: Reductant Leakage code indicates that a leak has been detected in the reductant (DEF/AdBlue) system. The reductant system is responsible for injecting DEF into the exhaust stream to reduce NOx emissions in diesel engines. A leak can prevent the system from functioning properly and may cause a reduction in emission control efficiency.
Step-by-step diagnostic guide
Action | Description | Tools Needed |
---|---|---|
Check for Other Codes | Use an OBD-II scanner to check for other related codes that could provide additional information about the reductant system’s malfunction. | OBD-II Scanner |
Inspect the Reductant System for Leaks | Perform a visual inspection of the reductant system, including all hoses, tanks, and fittings. Look for signs of leakage, such as wet spots, crystallization (common with DEF), or drips. | Flashlight, Safety Gloves |
Check Reductant Lines and Connections | Check all reductant lines and connections for signs of wear, cracks, or loose fittings. Ensure that all clamps and seals are secure and that there are no damaged lines that could be leaking. | Flashlight, Wrench |
Test System Pressure | Use a diagnostic tool to verify the system pressure of the reductant system. If the pressure is too low, it could indicate a leak or blockage in the system. Compare the readings to manufacturer specifications. | Diagnostic Tool, Pressure Gauge |
Inspect the Reductant Tank and Pump | Check the reductant tank and pump for any cracks, damage, or loose fittings that may contribute to the leakage. Ensure that the pump is working properly to maintain system pressure. | Flashlight, Multimeter |
Test the Reductant Injection System | Test the reductant injection system to ensure it is delivering the correct amount of reductant fluid into the exhaust system. Leaks or pressure issues may affect this performance. | Diagnostic Tool |
Repair or Replace Damaged Components | Repair or replace any damaged hoses, fittings, or components. Ensure all connections are tight and sealed properly to prevent further leaks. | Replacement Hoses, Fittings, Seals |
Clear the Code and Test Drive | After completing repairs, clear the P202D code using an OBD-II scanner. Test the vehicle to ensure that the leak has been resolved and the system is operating correctly. | OBD-II Scanner, Vehicle Owner’s Manual |
Recheck for Codes | After the test drive, re-scan the vehicle to verify that the P202D code has not returned. | OBD-II Scanner |

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