Fiat P0156 HO2S22 Sensor Range/Performance Condition

Description

OBD-II Trouble Code Description for P0156 Fiat

O2 Sensor Circuit

What does this mean?

OBD2 Code P0156 Fiat 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 Fiat 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 Fiat 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 Fiat
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 Fiat
Potential causes of an P0156 Fiat 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 Fiat:

2013 Fiat Viaggio,2013 Fiat Strada,2013 Fiat Panda UK Version,2013 Fiat Panda Trekking,2013 Fiat Panda 4×4,2013 Fiat Panda,2013 Fiat 500S,2013 Fiat 500L,2013 Fiat 500C Abarth,2012 Fiat Punto,2012 Fiat Palio,2012 Fiat Freemont AWD,2012 Fiat Freemont,2012 Fiat 695 Abarth Maserati Edition,2012 Fiat 500 Abarth,2011 Fiat Uno,2011 Fiat Punto Evo Abarth esseesse,2011 Fiat Punto Evo Abarth,2011 Fiat Idea,2011 Fiat Bravo,2011 Fiat 500 Sport,2011 Fiat 500 Coupe Zagato Concept,2011 Fiat 500C Abarth esseesse,2011 Fiat 500C Abarth,2010 Fiat Uno Cabrio Concept,2010 Fiat Sedici,2010 Fiat Punto Evo,2010 Fiat Doblo Cargo,2010 Fiat Doblo,2010 Fiat 500 Abarth R3T,2010 Fiat 500C,2009 Fiat Grande Punto Natural Power,2009 Fiat Fiorino Qubo,2009 Fiat 695 Abarth Tributo Ferrari,2009 Fiat 500 Barbie Concept,2009 Fiat 500 Abarth esseesse,2009 Fiat 500 Abarth Assetto Corse,2009 Fiat 500 Abarth,2008 Fiat Portofino Concept,2008 Fiat Panda Cross,2008 Fiat Grande Punto Abarth,2008 Fiat Grande Punto,2008 Fiat Fiorino,2008 Fiat Croma,2008 Fiat Bravo 1.6 Multijet 16v,2008 Fiat 500,2007 Fiat Panda 100HP,2007 Fiat Linea,2007 Fiat Grande Punto Abarth S2000,2007 Fiat Grande Punto Abarth Preview,2007 Fiat Bravo,2006 Fiat Ulysse,2006 Fiat Sedici,2006 Fiat Panda Multi Eco Concept,2006 Fiat Panda Cross,2005 Fiat Panda Alessi,2005 Fiat Panda 4×4 1.3 Multijet,2005 Fiat Oltre Concept,2005 Fiat Idea,2005 Fiat Grande Punto,2005 Fiat Doblo Cargo,2005 Fiat Doblo,2005 Fiat Croma,2005 Fiat 600 50th,2004 Fiat Trepiuno Concept,2004 Fiat Strada Malibu,2004 Fiat Stilo M.Y. 1.9 Multijet 5door,2004 Fiat Seicento,2004 Fiat Punto Rally,2004 Fiat Panda 4×4,2004 Fiat Multipla,2004 Fiat Idea 5terre Concept,2003 Fiat Strada,2003 Fiat Punto Sporting,2003 Fiat Punto Rally,2003 Fiat Punto Natural Power,2003 Fiat Punto Dynamic,2003 Fiat Punto Active,2003 Fiat Panda Emotion,2003 Fiat Panda Dynamic,2003 Fiat Panda Actual,2003 Fiat Panda,2003 Fiat Marrakech Concept,2003 Fiat Idea 1.9 Multijet Dynamic,2003 Fiat Idea 1.4 16v Emotion,2003 Fiat Idea,2003 Fiat Barchetta First Class of Alviero Martini,2003 Fiat Barchetta,2002 Fiat Ulysse Emotion 2.0 16v,2002 Fiat Ulysse 2.0 JTD,2002 Fiat Ulysse,2002 Fiat Stilo Multi Wagon Dynamic,2002 Fiat Stilo Multi Wagon Actual,2002 Fiat Stilo Multi Wagon,2002 Fiat Stilo Dynamic,2002 Fiat Stilo Active,2002 Fiat Stilo Abarth,2002 Fiat Stilo,2002 Fiat Simba Concept,2002 Fiat Palio Weekend,2002 Fiat Palio,2002 Fiat Multipla,2002 Fiat Albea,2001 Fiat Doblo

 

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