Description
OBD-II Trouble Code Description for P0401 Mazda
Exhaust Gas Recirculation Flow Insufficient Detected
What does this mean?
OBD2 Code P0401 Mazda definition:
EGR stands for Exhaust Gas Recirculation. It is part of the vehicle emmissions system, and is used to reduce combustion temperature and pressure to control Oxides of Nitrogen. There are generally three parts to the EGR system: the EGR valve, an actuator solenoid, and a differential pressure sensor EGR (DPFE). These things work together to deliver the correct amount of recirculation based on engine temperature, load, etc. The P0401 Mazda code means that OBD detected an insufficient amount of EGR.
Symptoms
Possible sumptoms of OBD code P0401 Mazda
You may notice drivability problems such as pinging (a.k.a. pre-ignition knock) when the engine is under load or the vehicle is at higher speeds. There may also be other symptoms.
Causes
Possible causes of OBD code P0401 Mazda
A code P0401 Mazda most likely means one or more of the following has happened: ?The DPFE (differential pressure feedback EGR) sensor is faulty and needs to be replaced ?There is a blockage in the EGR (tube), most likely carbon buildup ?The EGR valve is faulty ?The EGR valve may not be opening due to a lack of vaccuum
Possible Solutions
In fixing this code, it is quite common for people to just replace the EGR valve only to have the OBD code return. The EGR valve is not always the culprit. ?Use a vacuum pump and pull the EGR valve open while monitoring engine RPM’s & DPFE voltage. There should be a noticable difference in RPM’s with the EGR open ?Clean out the EGR valve and/or tubing to remove deposits ?Check the voltage at the DPFE, compare to specified values (refer to a repair manual for your specific model) ?Replace the DPFE sensor (with a good quality / OEM one) ?Replace the EGR valve
The OBD2 Code Information Be Applicable For Mazda:
2013 Mazda MX-5,2013 Mazda CX-9,2013 Mazda CX-5,2013 Mazda 6,2013 Mazda 5,2013 Mazda 3,2012 Mazda CX-5,2012 Mazda BT-50,2012 Mazda 3,2011 Mazda 6,2011 Mazda 5,2011 Mazda 2,2010 Mazda CX-7,2010 Mazda 3,2009 Mazda RX-8,2009 Mazda MX-5,2009 Mazda CX9,2009 Mazda 6,2009 Mazda 2,2008 Mazda MX-5,2008 Mazda 6,2008 Mazda 5,2008 Mazda 2,2007 Mazda CX-9,2007 Mazda CX-7,2006 Mazda MX5,2006 Mazda 6,2006 Mazda 3,2005 Mazda Atenza,2005 Mazda 6,2004 Mazda MPV,2004 Mazda 6,2004 Mazda 5,2004 Mazda 3,2003 Mazda RX-8
Note:
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