The P20E8 error code is a common issue in Citroën vehicles, indicating a problem with the diesel emissions control system. Specifically, the code signifies “Reductant Dosage System Performance/Efficiency Too Low – Bank 1 Unit 1.”
What Does the P20E8 Error Code Mean?
Essentially, the P20E8 error code means the Selective Catalytic Reduction (SCR) system isn’t functioning correctly. The SCR system is a crucial component in modern diesel vehicles, helping reduce harmful nitrogen oxides (NOx) emitted from the exhaust.
P20E8 error displayed on a Citroen dashboard
Several reasons can trigger the P20E8 error code. Some common causes include:
- Faulty NOx Sensor: The NOx sensor monitors the amount of nitrogen oxides in the exhaust stream. A malfunctioning sensor can send incorrect readings to the engine control unit, triggering the error code.
- AdBlue Injector Issues: The AdBlue injector sprays a urea solution (AdBlue) into the exhaust stream to reduce NOx emissions. A clogged or faulty injector can prevent proper urea injection, leading to the error code.
- Exhaust System Leaks: A leak in the exhaust system, especially before the SCR catalyst, can also cause the P20E8 error code.
How to Fix the P20E8 Error Code
Before troubleshooting, use an OBD2 diagnostic tool to read the error code and ensure no other error codes are present.
Once you’ve confirmed the P20E8 code, try these steps:
- Check AdBlue Level: Ensure sufficient AdBlue is in the tank. Low AdBlue can trigger the error code.
- Check the NOx Sensor: Test the NOx sensor’s resistance with a multimeter. Replace a faulty sensor.
- Check the AdBlue Injector: Inspect the AdBlue injector for clogs or damage. Replace a defective injector.
- Inspect for Exhaust Leaks: Thoroughly examine the exhaust system for leaks, particularly around the SCR catalyst. Repair any leaks found.
Consequences of Ignoring the P20E8 Error Code
Ignoring the P20E8 error code can lead to more severe problems, such as:
- Reduced Engine Performance: The vehicle may enter limp mode to prevent engine damage.
- Increased Fuel Consumption: A malfunctioning SCR system can increase fuel consumption.
- SCR Catalyst Damage: Continuously driving with a faulty SCR system can damage the catalyst, resulting in costly repairs.
Additional Tips and Advice
- Use genuine AdBlue, as low-quality AdBlue can damage the SCR system.
- Have a qualified workshop reset the error code after fixing the issue.
- Regular SCR system maintenance and inspection can help prevent future problems.
Mechanic working on a Citroen engine in a repair shop
Related Error Codes and Topics
Besides P20E8, other error codes related to the SCR system can occur. Some examples include:
- P20EE
- P20EF
- P20BA
If you have problems with your Citroën’s SCR system, consult a qualified workshop. Our experts at autorepairaid.com are available to assist you with diagnosis and repair.
