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Guide To P203B OBD Error Code Solutions

OBD Code P203B - Reductant Level Sensor Circuit Range/Performance

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The OBD-II P203B code is defined as a Reductant Level Sensor Circuit Range/Performance. Don’t panic when you see the check engine light illuminated, once you have discovered the code, it’s all about diagnosing it correctly. We have all the information you will need to understand why the code was set, and how to diagnose it, as well as information on what repairs or replacement may be needed to get rid of the P203B code.

Learn More About OBD Error Code P203B

This code is set when the Engine Control Module gets an unacceptable signal from the reductant level sensor. The leftover exhaust particles in your vehicle get converted into harmless gases. This happens with the assistance of the Diesel Exhaust Fluid (DEF). There is a process that enables this, it happens by increasing the temperature of the exhaust system, which in turn helps to burn off those particles. The DEF comes into the picture here, the fluid is injected into the exhaust stream which increases the temperature of the Diesel Particulate Filter. Hence it is able to convert the gasses and water. If any leftover NOx is present, then it is reduced by adding the Reductant Catalyst (SRC).

With the help of the Reductant Level Sensor, the ECM comes to know exactly how much DEF is present in the tank. The Discrete level sensor measures the tank level at three different heights, and the reductant level is measured based on how much liquid reductant is present. This makes the frozen reductant undetectable, and so the measured lever is used to calculate the exact quantity of reductant in the tank.

What causes this problem with the Reductant Level Sensor Circuit Range/Performance?

  • Reductant level sensor is not working properly
  • DEF storage tank has the wrong fluid in it
  • Electrical short or circuits and other electrical components

Replace/Repair These Parts To Fix Code P203B

  1. Engine wiring connectors - Sometimes the codes are set not because of a faulty sensor or components but connectors. These connectors are responsible for transferring electric signals, any damages to them can cause issues. You can repair or replace them online with us. Order from the convenience of your home and have it delivered to you right to your doorstep!
  2. Temperature sensor - The temperature sensor is responsible for measuring the temperature of the fuel in tank which helps the PCM to regulate the components easily. A faulty temperature sensor can make the whole system go haywire. Correct it through replacements and check if the P203A code goes away, otherwise go for replacement. We offer free shipping on orders over $99.
  3. Catalytic converter - Converts the toxic gases as well as pollutants in exhaust gas coming from the engine into less-toxic pollutants, it does this by catalyzing a redox reaction. This could be a cause for the P203B error to set. You can go for repair or replacement depending on the damages present. Order from PartsAvatar and track your shipment the whole way till it reaches you.
  4. Powertrain Control Module - The central processing unit of your vehicle, it monitors all the other modules and components. The PCM replacement would require reprogramming, which can be expensive try to repair and see if that can resolve the P203B error code. You can pick the right PCM fitment for your vehicle on our website. It’s easy to search and out 24/7 customer care executive can help you online too.
  5. Exhaust system - This mainly all the piping that guides exhaust gases away from the combustion inside your engine engine. If you have diagnoses any issues, repair them first and see if that has gotten rid of the P203B code. If not, go for replacement with PartsAvatar. We ship to the remotest corners of Canada from our warehouses.
  6. Exhaust Gas Temperature sensors - This is a meter that is used to monitor the exhaust gas temperature of the combustion engine of the vehicle. You can try to repair the damages you have found or replace it with PartsAvatar. Order online easily today!

Symptoms Of The OBD Error Code P203B

Well, if you are looking to know about the common symptoms related to this error code P203B, we are have worked out a small list to help you discover this error code with your vehicle.

Common Symptoms

  • Unacceptable reading of the DEF (Diesel exhaust fluid) level found
  • The Exhaust emissions are not within the manufacturers range of specifications
  • The Check engine light is illuminated
  • Increase in smoke noted
  • DEF warning present on the instrument cluster of the vehicle

How To Correct P203B Reductant Level Sensor Circuit Range/Performance

Once you know the symptoms of your vehicle’s problem, it becomes easy to detect it and get started with solving it. So, next on our list is few common steps to correct P203B this issue with your vehicle’s

  • Repair or replace the Exhaust system components
  • Repair or replace catalytic converter
  • Repair or replace the temperature sensor
  • Repair or replace ECM module
  • Repair or replace the damaged engine wiring and connectors

If you need parts to fix this issue, you no longer need to search for them. We at PartsAvatar Canada have an extensive range of auto parts in stock from you, ranging from all replacement parts to all Connectors, Temperature sensor, Catalytic converter, PCM, Exhaust gas, Exhaust system and EGT sensors parts.

Easy Diagnosis Of Engine Error OBD Code P203B

You can diagnose the P203B code by following the diagnostic steps below, however if you feel you aren't very confident you can take help from a professional especially in any advanced steps.

Begin with collecting all the necessary information for the diagnosis. If you have all the information handy, it will make the process faster and more accurate. Research the Technical Service Bulletins (TSB) for any issues you already knew were present. Make sure you match the TSB exactly to your vehicle's make, model, year of manufacture and engine. In case you feel you won’t be able to manage doing the diagnosis on your own, you can always take assistance from a trained diagnostician or mechanic.

You can now proceed to connect your scanner to the vehicle diagnostic port and retrieve all the codes. Now clear the codes and go on a test drive. Make note of all the codes that have set and freeze frame the data. The diagnosis has to be done for all the codes that are now present. Using the technical service bulletins and a reliable information source for your vehicle locate the Diesel Exhaust fluid storage tank. Once you have successfully located it, using a dipstick manually measure the level of the fluid. Top up the fluid and move on to the next step.

If you find that the level is still showing low after filling the DEF tank, then there’s an issue with the reductant level sensor. You will need to replace it and this may help get rid of the P203A code. Remember that replacing the sensor is tricky as it is mounted to the tank, ensure you catch any of the DEF which may come out while replacing it. Check the electrical connection of the reductant level sensor connector. To know the specific values and procedures for testing the level sensor you can refer the service data for the specific vehicle. This will be there in the TSB. You can use a multimeter to test resistance levels. If the values aren’t as needed by the manufacturer you will have to go for replacement of sensor. Finally it’s time to inspect the reductant level sensor wiring harness for any damages. You may find chafed or burned wires. All the bare wires will need to be repaired, you can also replace them if you feel that would resolve the matter properly. Also, keep in mind that the repairs should last. Now move on to the harness and ensure that it’s fastened safely and not close to the moving parts.

Common Mistakes When Diagnosing the P203B Code

  • Damaged DEF tank
  • Not following the diagnostic steps correctly
  • Hastily replacing the sensor and overlooking the issue with the electrical system, wiring and connectors

Other Diagnostic Codes Related To OBD Code P203B

P203A - Reductant Level Sensor Circuit

P203C - Reductant Level Sensor Circuit Low

P203D - Reductant Level Sensor Circuit High

P203E - Reductant Level Sensor Circuit Intermittent/Erratic