P049B OBD Error Code: Problem & Solutions

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Your vehicle shows the OBD Error P049B and you’re confused what it even means! We will break it down for you; to know more about the error, it’s diagnosis and most importantly how to fix it. A vehicle's Exhaust Gas Recirculation system functions to primarily reduce the combustion temperature, hence reducing emissions. Sometimes the Engine Control Module also known as the PCM does not detect the amount of flow that the EGR is requesting, this leads to the onset of code P049B.

The more recently built vehicles use a step motor to control the rate of flow of EGR from the exhaust manifold. There are four winding phases to this motor. According to the output pulse signal sent from the ECM, the EGR system is operational. Two windings, following a sequence are turned On and Off, each time the on pulse is issued; the valve will open and close, which changes the flow rate. In case no change in the flow rate is needed, the ECM won’t issue the pulse signal. For the vales to remain at any specific opening, a certain voltage signal is issued.

What causes this problem with Exhaust Gas Recirculation "B" Flow Insufficient Detected?

• A Defect in the valve of the EGR
• Clogging of the EGR passage/s with carbon
• DPFE hoses collapsed or cracked
• DPFE, MAP, or MAT Sensors faulty
• EGR valve or related sensors show open or shorted circuits

1. Exhaust Gas Recirculation - If you note that the EGR is underperforming, you will have to proceed with either repairing or replacing it.
2. EGR Valve - A faulty valve can cause damage to the EGR system, if repairing is not possible, replace it with high quality EGR Valves available at Parts Avatar.
3. Engine Control Module - This is a crucial part of your vehicle, malfunctioning PCM can cause multiple issues. At Parts Avatar you can replace it hassle free by ordering online.
4. Vacuum Switching Valve - Also known as the VSV, is very important. Try to repair it as soon as your find any defects, if that doesn’t work, you will have to replace it. You will surely find one that’s compatible to your vehicle at Parts Avatar.
5. EGR Solenoid - It is another very important part of the EGR system. If you find fault in it, then ensure if repairing will fix it completely, otherwise purchase one easily online at our website. We offer free shipping for orders over CAD$99.
6. EGR Vacuum - Any leaks or overall poor functioning of the EGR Vacuum is not good. Repair or replace it as per need.
7. Exhaust Manifold - Is a significant part of the EGR System, and to correct the Code P049B you may have to replace it depending on how bad it is.

The symptoms of the OBD Codes of similar nature can be confusing. Hence, we have taken the role of informing you of all the common symptoms associated for when the OBD Error Code P049B Exhaust Gas Recirculation "B" Flow Insufficient Detected.

Common Symptoms

• Decrease in the performance of engine
• Increase in the consumption of fuel by vehicle

There is one simple way that can help you correct OBD Error P409B:

• Replace of the EGR Valve with automobile compatible and good quality EGR

PartsAvatar has solutions to all your automobile replacement needs, with several categories and car parts to choose from that are compatible with your specific vehicle.

Here are few ways to easily diagnose this error code:

• Your diagnosis will begin by first locating the vehicle diagnostic connector. Retrieve all the stored codes with the scanner and record the information, this may be needed as diagnosis is made. Next, test-drive the vehicle and observe if the code immediately resets.
• The Technical Service Bulletin (TSB) of your vehicle can come handy in discovering solutions to your EGR system issues. Simply match your vehicle to the codes stored and the symptoms exhibited. These are carefully derived from thousands of specialists in automobile repairs and contain diagnostic hints for vehicle owners. Hence, can be confidently considered as reliable.
• Next use a Digital volt/ohmmeter (DVOM), diagnostic scanner and a reliable information source for your vehicle if the P049B code is stored right after you cleared all the codes.
• Inspect the EGR valve visually. Also, observe the wiring and connectors related to it. You’re mainly looking for any damage caused to the harnesses routed near the hot exhaust manifolds and the jagged edges mostly associated with the exhaust shields.
• In order to prevent controller damage, simply disconnect all the related control modules from the circuit before proceeding to test resistance/continuity with the DVOM
• Next you will have to make use of the scanner to manually activate the EGR system. A certain rate of speed is required by most EGR systems before the automatic activation can happen. Wiring diagrams and connector pinout charts will come handy now, they will help you test each individual EGR valve connector circuit. These charts and resources will be available in your vehicle information source. However, you may find some circuits which may not conform to the specifications of the manufacturer. These will have to be followed back to the source (the PCM connector, mostly) and then re-tested. If there’s no output signal noticed from the PCM, it could be due to a defecting PCM or even an error in the programming of the PCM. Accordingly, you can repair or replace the open/shorted circuits.
• Now you can use the DVOM to test the EGR valve and the related sensors. Use the same vehicle information source to check if all circuits follow manufacturer’s specifications. It there is misalignment with the manufacturer’s specification of the step-down EGR valve and/or any other related sensors, they should be replaced.

Common Mistakes When Diagnosing the P049B Code

• EGR valve fails to perform as usual
• Powertrain Control Module (PCM) fails to work completely or as efficiently as before
• Wiring issue in the vehicle