Kia P0478 Exhaust Pressure Control Valve High

Description

OBD-II Trouble Code Description for P0478 Kia

Exhaust Pressure Control Valve High

What does this mean?

OBD2 Code P0478 Kia 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 Kia
– Engine Light ON (or Service Engine Soon Warning Light)

Causes

Possible causes of OBD code P0478 Kia
– 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 Kia:

2013 Kia Sorento,2013 Kia Provo Concept,2013 Kia Niro Concept,2013 Kia K9,2013 Kia Cross GT Concept,2013 Kia Ceed SW,2013 Kia Ceed,2013 Kia Carens,2013 Kia CUB Concept,2012 Kia Soul,2012 Kia Rio,2012 Kia Ray,2012 Kia Picanto,2012 Kia K2,2012 Kia Grand VQ-R,2011 Kia Sportage,2011 Kia Sorento,2011 Kia Pro Ceed,2011 Kia Optima Hybrid,2011 Kia Optima,2011 Kia Naimo Concept,2011 Kia KV7 Concept,2011 Kia GT Concept,2011 Kia Cadenza,2010 Kia Venga,2010 Kia Soul,2010 Kia Sorento,2010 Kia POP Concept,2010 Kia Forte Koup,2010 Kia Forte,2010 Kia Ceed SW,2010 Kia Ceed,2009 Kia VG Concept,2009 Kia Soul,2009 Kia Optima,2009 Kia No3 Concept,2009 Kia Magentis,2009 Kia Borrego,2008 Kia eco ceed Concept,2008 Kia Pro-cee-d,2008 Kia Picanto,2008 Kia KOUP Concept,2007 Kia cee-d,2007 Kia Rondo,2007 Kia Kue Concept,2007 Kia Carens,2006 Kia Sportage,2006 Kia Spectra

 

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