P0439 Citroen Catalyst Heater Control Circuit Bank 2
Possible causes
– Catalyst Temperature Sensor harness is open or shorted
– Catalyst Temperature Sensor circuit poor electrical connection
– Faulty Catalyst Temperature Sensor
– Catalyst Temperature Sensor circuit poor electrical connection
– Faulty Catalyst Temperature Sensor
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P0439 Citroen Description
The Engine Control Module (ECM) monitors the switching frequency ratio of heated oxygen sensors 1 (front O2 sensor) and heated oxygen sensors 2 (rear O2 sensor).
A three way catalyst converter (Manifold) with high oxygen storage capacity will indicate a low switching frequency of heated oxygen sensor 2. As oxygen storage capacity decreases, the heated oxygen sensor 2 switching frequency will increase.
When the frequency ratio of heated oxygen sensors 1 and 2 approaches a specified limit value, the three way catalyst malfunction is diagnosed.
Citroen Vehicle:2013 Citroen,2012 Citroen,2011 Citroen,2010 Citroen,2009 Citroen,2008 Citroen,2007 Citroen,2006 Citroen,2005 Citroen,2004 Citroen,2003 Citroen,2002 Citroen,2001 Citroen,2000 Citroen,1999 Citroen,1998 Citroen,1997 Citroen,1996 Citroen,