Cadillac P0156 HO2S22 Sensor Range/Performance Condition

Description

OBD-II Trouble Code Description for P0156 Cadillac

O2 Sensor Circuit

What does this mean?

OBD2 Code P0156 Cadillac definition:
The o2 (oxygen) sensors measure oxygen content in the exhaust. The PCM (powertrain control module) then uses this information to regulate fuel injector pulse. The o2 sensors are very important for the proper operation of the engine. Innacurate or faulty o2 sensors can cause the PCM to add or take away fuel based on the faulty o2 sensor voltage which can cause a host of problems. A P0156 Cadillac code definition:the Bank 2,2 o2 sensor or the downstream (post-cat) o2 sensor on Bank 2. It is a four wire sensor. The PCM supplies a ground circuit and a reference voltage circuit of about 0.5 volts. Also for the o2 sensor heater element there is a battery voltage supply wire and another ground circuit for that. The o2 sensor heater allows the o2 sensor to warm up faster, thus achieving closed loop in less time than it would normally take for the exhaust to warm the sensor up to operating temperature. The O2 sensor varies the supplied reference voltage based on oxygen content in the exhaust. It is capable of varying from about 0.1 to 0.9 volts, 0.1 V indicating lean exhaust and 0.9 V indicating rich exhaust. This P0156 Cadillac code indicates that the Bank 2, 2 o2 sensor is stuck low for too long or isn’t active at all.

Symptoms

Possible sumptoms of OBD code P0156 Cadillac
Often post-cat o2 sensor problems present few symptoms since they are inputs to the PCM to monitor catalytic converter quality and don’t directly control fuel. sometimes no symptoms are noticeable. However the following may be possible on some vehicles: MIL (Malfunction Indicator Lamp) illumination Decrease in MPG Increase in tailpipe emissions

Causes

Possible causes of OBD code P0156 Cadillac
Potential causes of an P0156 Cadillac code include: Bad O2 sensor Signal shorted to voltage Wiring problems due to contact with exhaust components Holes in exhaust near o2 sensor

Possible Solutions

If you have access to a scan tool, check the signal voltage for the Bank 2,2 oxygen sensor with the engine at normal operating temperature. Is it stuck low currently? If so, increase RPM for a few seconds and see if it affects the reading. If it begins working with increased RPM, check for holes in the exhaust near the o2 sensor that may cause a false lean. If the exhaust pipe is intact, the sensor is sluggish, replace it. If the Bank 2,2 o2 sensor voltage reading remains low with increased RPM, unplug it and then observe the reading. It should have increased to about 0.5 volts or thereabouts. If it did, check for water intrusion or other connector problems. If none are found, replace the shorted o2 sensor. If the voltage reading is still stuck low after unplugging the sensor, then suspect a wiring problem. Using a voltmeter, with the o2 sensor unplugged, check for voltage on the signal circuit at the o2 sensor connector(PCM side). It can vary with model, but should be about 0.5 volts and not above 1 volt. If the voltage reading is too high, repair short to voltage on signal circuit. If the signal voltage checks out, suspect the PCM.


The OBD2 Code Information Be Applicable For Cadillac

2013 Cadillac XTS,2013 Cadillac Elmiraj Concept,2013 Cadillac ATS,2012 Cadillac SRX,2011 Cadillac Ciel Concept,2011 Cadillac CTS Coupe,2011 Cadillac CTS-V Sport Wagon,2011 Cadillac CTS-V Coupe Race Car,2011 Cadillac CTS-V Coupe,2011 Cadillac CTS-V Black Diamond Edition,2010 Cadillac XTS Platinum Concept,2010 Cadillac Urban Luxury Concept,2010 Cadillac SRX,2010 Cadillac SLS,2010 Cadillac CTS Sport Wagon,2010 Cadillac Aera Concept,2009 Cadillac Presidential Limousine,2009 Cadillac Escalade Hybrid,2009 Cadillac Converj Concept,2009 Cadillac CTS-V,2008 Cadillac STS,2008 Cadillac Provoq Concept,2008 Cadillac Escalade Platinum,2008 Cadillac CTS Coupe Concept,2008 Cadillac CTS,2008 Cadillac BLS Wagon,2007 Cadillac SRX European Version,2007 Cadillac SLS,2007 Cadillac Escalade European Version,2007 Cadillac Escalade EXT,2007 Cadillac Escalade ESV,2007 Cadillac Escalade,2007 Cadillac BLS Sport,2006 Cadillac XLR Star Black Limited Edition,2006 Cadillac XLRV,2006 Cadillac STSV,2006 Cadillac SRX,2006 Cadillac Escalade ESVe Limousine,2006 Cadillac DTS Limousine,2006 Cadillac DTS,2006 Cadillac CTS,2006 Cadillac BLS,2005 Cadillac XLR Euro,2005 Cadillac STS SAE 100,2005 Cadillac STS Euro,2005 Cadillac STS,2005 Cadillac SRX Euro,2005 Cadillac SRX,2005 Cadillac CTS Euro,2005 Cadillac CTS-V Euro,2005 Cadillac BLS Show Car,2004 Cadillac XLR,2004 Cadillac Seville SLS,2004 Cadillac SRX,2004 Cadillac Escalade ESV Platinum,2004 Cadillac Escalade ESV Executive Edition,2004 Cadillac DeVille Armored,2004 Cadillac CTSV Race Car,2004 Cadillac CTSV,2004 Cadillac CTS,2003 Cadillac Sixteen Concept,2003 Cadillac Escalade EXT,2003 Cadillac Escalade ESV,2003 Cadillac CTSV with Accessories,2003 Cadillac CTS,2002 Cadillac Vizon Concept,2002 Cadillac Seville STS,2002 Cadillac Escalade EXT,2002 Cadillac Escalade,2002 Cadillac DeVille,2002 Cadillac Cien Concept,2001 Cadillac Seville,2001 Cadillac Eldorado,2001 Cadillac DeVille Presidential Limousine,2001 Cadillac DeVille DTS,2000 Cadillac Seville STS,2000 Cadillac Imaj Concept,2000 Cadillac Escalade,2000 Cadillac Eldorado ETC,2000 Cadillac DeVille

 

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