Nissan P0478 Exhaust Pressure Control Valve High

Description

OBD-II Trouble Code Description for P0478 Nissan

Exhaust Pressure Control Valve High

What does this mean?

OBD2 Code P0478 Nissan definition:
Exhaust Back Pressure Regulator – Is a variable position valve that controls exhaust back pressure during cold ambient temperatures to increase cab heat and decrease the amount of time needed to defrost the windshield. The PCM uses the measured exhaust back pressure, (ambient) intake air temperature, engine oil temperature and engine load to determine the desired exhaust back pressure. Valve position is controlled by switching the output signal circuit to 12 volts inside the PCM. On/off time is modulated from 0 to 99 % dependent upon the exhaust back pressure desired. Upon each initial engine start-up, the PCM exercises the exhaust back pressure valve by commanding it to cycle on and off once. If upon start-up the temperature of intake air sensed by the IAT sensor is < 37¡ãF (5¡ãC) and the oil temperature sensed by the EOT sensor is between 32¡ã-140¡ãF (0-60¡ãC) it will continue to keep the back pressure valve partially closed. As the oil temperature rises during engine operation, the PCM will control the valve in response to the rising oil temperature.

Symptoms

Possible sumptoms of OBD code P0478 Nissan
– Engine Light ON (or Service Engine Soon Warning Light)

Causes

Possible causes of OBD code P0478 Nissan
– Exhaust Back Pressure Valve The Error code is generally activated on detection of the following conditions: An open or shorted to ground control circuit can be detected by an on demand output circuit check performed during the engine off test. Problems with either the Exhaust Back Pressure Device or the tube between the exhaust manifold and the EBP sensor can be detected during the exhaust back pressure step test, in which the PCM commands and then measures a specific preprogrammed pressure and then measures time for pressure decay during the engine running test. If the PCM detects an EBP, EOT or IAT sensor fault it will disable the exhaust back pressure regulator.

Possible Solutions

Check the Exhaust Back Pressure Valve (EBPV) butterfly valve is opening and closing freely and not sticking. If it seems to move freely you can then check the connector and circuit for the EBPV solenoid.


The OBD2 Code Information Be Applicable For Nissan:

2013 Nissan Pathfinder,2013 Nissan Murano,2013 Nissan Juke Nismo,2013 Nissan GT-R,2013 Nissan Altima Sedan,2013 Nissan Almera,2013 Nissan 370Z,2012 Nissan Tiida,2012 Nissan Sunny,2012 Nissan Qashqai,2012 Nissan Murano,2012 Nissan Micra ELLE,2012 Nissan Micra DIG-S,2012 Nissan Maxima,2012 Nissan Juke Shiro,2012 Nissan GT-R,2012 Nissan Extrem Concept,2011 Nissan X-Trail,2011 Nissan Rogue,2011 Nissan Quest,2011 Nissan Pivo 3 Concept,2011 Nissan Patrol,2011 Nissan Murano,2011 Nissan Micra,2011 Nissan LEAF,2011 Nissan Juke,2011 Nissan GT-R,2011 Nissan 370Z,2010 Nissan Qashqai,2010 Nissan Pathfinder,2010 Nissan Navara,2010 Nissan NV200,2010 Nissan GT-R SpecV,2010 Nissan Cube,2010 Nissan Altima Sedan,2010 Nissan Altima Coupe,2010 Nissan 370Z Roadster,2009 Nissan Xterra,2009 Nissan Pixo,2009 Nissan Note,2009 Nissan Murano,2009 Nissan Maxima,2009 Nissan Frontier,2009 Nissan 370Z,2008 Nissan X-Trail,2008 Nissan Rogue,2008 Nissan Pathfinder,2008 Nissan GT-R,2007 Nissan Sentra SE-R,2007 Nissan Mixim,2007 Nissan Altima,2006 Nissan Urge Concept,2006 Nissan Note,2006 Nissan 350Z,2005 Nissan Zaroot Concept,2005 Nissan Xterra,2005 Nissan Terrano,2005 Nissan Sport Concept,2005 Nissan Primera,2005 Nissan Pivo Concept,2005 Nissan Pickup,2005 Nissan Patrol,2005 Nissan Pathfinder,2005 Nissan Micra,2005 Nissan Altima,2004 Nissan Titan,2004 Nissan Tiida

 

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