Error Code P20ED: What It Means & What To Do?

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Is your Car’s Check Engine Light illuminating on the dashboard? Do you find sudden decrease in the fuel economy? And is the car engine running rough with black smoke coming from tailpipe? This might be the indication of problems with the SCR pre-catalyst of the car which in other words can be an OBD P20ED error.

OBD code P20ED means SCR NOx Pre-Catalyst - Over Temperature Bank 1 Issue.

Selective Catalytic Reduction (SCR) is an advanced active emissions control technology system that injects a liquid-reductant agent through a special catalyst into the exhaust stream of a diesel engine. The reductant source is usually automotive-grade urea, otherwise known as Diesel Exhaust Fluid (DEF). The DEF sets off a chemical reaction that converts nitrogen oxides into nitrogen, water and tiny amounts of carbon dioxide (CO2), natural components of the air we breathe, which is then expelled through the vehicle tailpipe.

SCR technology is designed to permit nitrogen oxide (NOx) reduction reactions to take place in an oxidizing atmosphere. It is called "selective" because it reduces levels of NOx using ammonia as a reductant within a catalyst system. The chemical reaction is known as "reduction" where the DEF is the reducing agent that reacts with NOx to convert the pollutants into nitrogen, water and tiny amounts of CO2. The DEF can be rapidly broken down to produce the oxidizing ammonia in the exhaust stream. SCR technology alone can achieve NOx reductions up to 90 percent.

What causes this problem with the SCR NOx Pre - Catalyst - Over Temperature Bank 1?

• Faulty exhaust temperature sensor
• SCR system not working properly
• Defective SCR injector
• SCR controller module programming error
• Pre-catalyst exhaust leaks

1. Engine Control Module – ECM failures and faults can be very difficult to find and resolve as these are very rare and might require a complete reprogramming of the system to avoid wrong codes from getting stored in the system, leading to misdiagnosis. Replace it now!
2. Powertrain Control Module – Faulty PCM can disrupt the normal functioning of the vehicle by affecting the transmission system and the fuel delivery system. This will cause the system to store wrong OBD error and thus can lead to misdiagnosis.
3. Diagnostic Tools – Take help of a professional mechanic to diagnose OBD code error. Use high grade diagnostic tools to resolve this issue. Buy new tools and equipment from us!
4. Fuel Injector – Bad fuel injectors can cause starting issues, poor idles and affected performance. Thus, the replacements are in order. Buy new fuel injectors now!
5. Exhaust Gas Recirculation Valve - If the PCM detects any fault in the vehicle’s EGR valve circuit, it will set up the check engine light so that the driver is notified about the fault. Properly check for the EGR valve faults leading to this OBD code getting stored in the system. Get the faulty EGR valve replaced or else this fault code can turn up.
6. Diesel Exhaust Fluid Pump – Faulty DEF pump can lead to increased emission and affected vehicle performance. It can also hamper the fuel economy and the power output of the vehicle. Thus, replace faulty DEF pump now!
   

Interested in knowing the symptoms to obd code P20ED? If yes, then you have arrived at the right place. We at PartsAvatar have listed out few common symptoms associated with this fuel injector problem.

Common Symptoms

• Reduced/abnormal engine performance
• Affected fuel efficiency
• Lean exhaust codes
• Increased emissions from the tailpipe

It is very important to fix the fault code P20ED. So here are some ways with which you can correct this issue:

• Bad Reductant Injector Valve replacement
• Diesel Exhaust Fluid Pump replacement
• EGR valve replacement
• Faulty wiring and connector repairs
• Powertrain Control Module repair and reprogramming

There is no need to get strained if your OBD Code is still flashing up as we are here at your service. Have a look at our superior variety of DTC, Powertrain, SCR, EGR, DEF, catalytic converter, Temperature sensors, SCS, PCM, catalyst exhaust leaks, DVOM and many more. Now all your problems would vanish within no time.

It is essential to diagnose this fault code. Here are some steps which a mechanic should follow for diagnosing the problem that triggered a P20ED code to be stored:

• Take the help of an experienced mechanic who will visually inspecting the exhaust system.
• Find and freeze frame data with the code. Then, clear the code and take the vehicle on a test drive under the same conditions.
• If the code reappears, perform a visual inspection of the components and its wiring.
• If the wiring is okay, the injector itself will be tested to confirm operation.
• The mechanic will repair or replace faults in relation to the reductant injection air pressure sensor, DEF pump and EGR valve. Also check for any wiring and harness issues and correct the damaged wirings.
• If there is no problem found, check for the faulty ECU. Although, this fault is very rare but can be a reason for problematic exhaust system, thus hampering the engine performance. The ECU needs to be replaced in such condition and has to be reprogrammed to erase any stored faulty error.
• Visual inspect the SCR injection system, exhaust temperature sensors, NOx sensors, and oxygen (02) sensor harnesses and connectors and check for burnt or damaged wiring and or connectors that might need repair or replacement.

Common Mistakes When Diagnosing the P20ED Code

• Powertrain Control Module (PCM) faulty
• SCR injector issue
• Wiring and connector issue