P20B9 OBD Error Code: Problem & Solutions

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What does P20B9 error code refer to? What are its symptoms and causes? Are you looking for even more information? Then keep reading further. Both the sender assembly and the reductant heater has a pickup tube for the reductant pump module which is nothing but an electric heating element and also functions as a reductant temperature sensor and an electrode type level sensor. The heating element is placed right at the top of the pickup tubes inlet filter.

When the diesel exhaust fluid temperature drops down to the freezing point of 12°F (-11°C), the reductant temperature sensor will identify this and then the powertrain control module will order the glow plug control module to offer the voltage to the heating element. During the cold ambient temperature, the heating element will melt the liquid reductant within the reductant heater and as well as the sender assembly reservoir.

What causes this problem with the Reductant Heater A Control Circuit/Open?

• The reductant heater might be broken.
• The reductant heater harness might either be shorted or you might see an opening in the circuit.
• Very poor electrical connection in the reductant heater circuit.

1. Temperature Sensor - Illumination of the check engine light and DPF light show that the temperature sensor is defective. Get rid of it as soon as possible.
2. Diesel Exhaust Fluid - If the DEF is dirty, it can block the filter and can cause pressure and temperature differentials which affects the whole performance of the engine. The dirty DEF has to be quickly replaced to avoid P20B9 error code.
3. Powertrain Control Module - Bad input from the sensors as well as other control modules will cause the malfunctioning of the PCM. Get the right replacement for your defective PCM at the best prices from Parts Avatar.
4. Reductant Heater - An opening or shorted circuit in the reductant heater can give rise to engine performance issues. Get rid of the P20B9 error by replacing the damaged reductant heater.
5. Glow Plug - The engine will start slowly or hesitate to start if the glow plug is damaged. Get the right replacement for the faulty glow plugs from PartsAvatar at the best prices.

It is essential to know the symptoms of an issue as only then you would be able to solve the problem. So that’s why we have listed out some major symptoms of OBD Code P20B9 here:

Common Symptoms

• Impossible for the DPF regeneration to take place.
• You will notice either of the lights, that is the engine light or the warning light of the service engine turned on.

Here are some ways with the help of which you will be able to correct the OBD Code P20B9:

• Changing the broken reductant heater ‘A’ control circuit.
• The opening or the shorted circuit of the reductant heater ‘A’ control must be quickly fixed.
• Quickly replacing the dirty diesel exhaust fluid.
• Replacing the broken glow plugs.

There is no need to be anxious as Parts Avatar – Car Parts Online is here to help you out! We have a high-grade temperature sensor, diesel exhaust fluid, powertrain control module, reductant heater, diesel glow plugs, engine control module, body control module and a lot more for our precious customers.

Here are some steps which you should follow in order to diagnose this P20B9 fault code:

• The engine control module and the powertrain control module in combination with the engine system will start the P20B9 error code solenoid valve so that the oil control pressure to the engine mechanism which is installed in the valve system is controlled to change the timing of the valve between high and low.
• If there is an opening or short circuit in the engine system, then the P20B9 error code will be stored in the vehicle.
• This is a general type of error code, where the diagnosis process and the repair work is not difficult to execute.
• It is always best to handover to the experienced professionals as there are numerous circuits involved.
• Whenever this error arises, the mechanic will use a scanner to check the trouble codes in the vehicle. But a trained professional will use an advanced scanner like Autohex- to check for advanced diagnostic process.
• The mechanic will carefully look into the reductant heater if it is broken, damaged or corroded. If it is defective it will be replaced quickly.
• After this, the mechanic will look for possible damages in the harness of the reductant heater and see if there are any openings or short circuit. Any damage to this component can also result in the storing of the error code and so it will be addressed immediately.
• As a very rare case, the mechanic will find the powertrain control module to be faulty which has to be replaced quickly.
• If there are any other error codes, they must be rectified first, before further proceeding with the P20B9 error code.
• After the diagnosis, it is good to always reset the code and the vehicle must be test driven to know if the issue is resolved.
• Test driving the vehicle will help the mechanic to know as to where the error occurred.

Common Mistakes When Diagnosing the P20B9 Code

• Problematic wires.
• Failure of the glow plug control module.
• Reductant tank heater might be defective.