The P20EC: SCR NOx Catalyst – Over Temperature Bank 1 fault code indicates that the Selective Catalytic Reduction (SCR) NOx catalyst in Bank 1 is operating at a temperature that is too high. This excessive temperature can cause damage to the catalyst and reduce its ability to control NOx emissions. The issue may be caused by a faulty temperature sensor, issues within the SCR catalyst, or problems in the exhaust system.
P20EC – Quick Overview
| Code | Information |
|---|---|
| Meaning | P20EC: SCR NOx Catalyst – Over Temperature Bank 1 |
| Is it serious? | Yes, high temperatures can damage the catalyst and affect emissions control, potentially leading to more severe exhaust system issues. |
| Possible causes | – High temperature in the SCR NOx catalyst for Bank 1 – Faulty temperature sensor – Issues with the catalyst or exhaust system |
| How to diagnose? | – Measure the temperature of the SCR NOx catalyst – Test the temperature sensor – Inspect the catalyst and exhaust system |
P20EC Meaning
The P20EC fault code indicates that the SCR NOx catalyst in Bank 1 has exceeded its normal operating temperature. This could lead to damage to the catalyst and result in inefficient NOx reduction, affecting emissions control. Possible causes include a faulty temperature sensor, malfunctions within the SCR catalyst itself, or issues with the exhaust system leading to excess heat.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to check for any additional codes related to the temperature sensor or SCR system, which may provide further details on the issue. | OBD-II Scanner |
| Measure the Temperature of the SCR NOx Catalyst | Use a diagnostic tool or infrared thermometer to measure the actual temperature of the SCR NOx catalyst to confirm the over-temperature condition. | Diagnostic Tool, Infrared Thermometer |
| Test the Temperature Sensor | Use a multimeter to test the functionality of the temperature sensor and verify that it is reading the correct temperature. | Multimeter, Diagnostic Tool |
| Inspect the Catalyst and Exhaust System | Visually inspect the SCR NOx catalyst and exhaust system for signs of overheating, blockages, or damage that could be contributing to the high temperature. | Flashlight, Diagnostic Tool |
| Repair or Replace Faulty Components | If the temperature sensor is faulty or the exhaust system is damaged, repair or replace the affected components to restore normal operation. | Replacement Parts, Tools |
| Clear the Code and Test Drive | After completing repairs, clear the code using an OBD-II scanner and test drive the vehicle to confirm that the issue has been resolved. | OBD-II Scanner, Vehicle Manual |
| Recheck for Codes | After the test drive, rescan the vehicle to ensure the P20EC code does not return. | OBD-II Scanner |
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Hi, I am Juraj “Yuri” Lukacko. I got frustrated by unhelpful and scammy mechanics, so I decided to learn everything about car diagnostics myself. I test dozens of new car diagnostic tools every month along with learning new strategies to fix and customize cars. About Juraj Lukacko (Yuri)