Reductant Leakage Detected
The P202D code indicates that the diesel exhaust fluid (DEF) system has detected a leak in the reductant delivery system. This can be caused by a faulty DEF injector, damaged lines, or a leaking DEF tank. The system monitors the amount of DEF injected and compares it to expected values; if a discrepancy is found, this code is set. Continued operation may lead to reduced NOx conversion and potential damage to the SCR system.
01. Most Common Causes
- Leaking DEF injector
- Cracked or loose DEF lines
- Damaged DEF tank or pump seal
- Faulty DEF quality sensor
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine performance or power
- Increased exhaust emissions
- Possible DEF warning message on dashboard
03. Step-by-Step Diagnosis
Step 1: Visually inspect all DEF lines, connections, and the injector for leaks.
Step 2: Use a scan tool to monitor DEF injection quantity and compare to commanded values.
Step 3: Perform a leak test by pressurizing the DEF system and checking for pressure drop.
Step 4: Inspect the DEF tank and pump for cracks or seal failures.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as the DEF system may not function properly, leading to increased emissions and potential damage to the SCR system. Short trips may be okay, but the vehicle may enter limp mode.
How much does it cost to fix?▼
The cost to diagnose and repair a DEF leak typically ranges from $50 to $150 for diagnosis, plus parts and labor. Replacing a DEF injector or line can cost $200-$500 depending on the vehicle.