BMW P0154 A/F Sensor 21 Heater System Malfunction

Description

OBD-II Trouble Code Description for P0154 BMW

O2 Sensor Circuit No Activity Detected

What does this mean?

OBD2 Code P0154 BMW definition:
The oxygen sensors are critical to the engine running properly. It basically informs the PCM (Powertrain Control Module) of oxygen content of the exhaust. The PCM then uses this information to regulate fuel into the engine and maintain proper air:fuel ratio. It is a four wire sensor, with the PCM providing a reference/signal voltage of about half a volt (0.5v) to the sensor. It usually provides a ground also. The other two wires are dedicated to the oxygen sensor heater element. This heater allows the sensor to warm up faster, which allows the engine to enter closed loop faster, reducing startup emissions. The heater element is supplied a 12v feed from the power distribution center (usually) and a ground. The oxygen content of the exhaust affects the O2 sensor resistance. This resistance produces a counter voltage on the reference/signal wire that the PCM will use to analyze oxygen in the exhaust. Lean exhaust produces low voltage, while rich exhaust produces high voltage. The oxygen sensor is capable of varying between 0.9v (rich) and 0.1v (lean). Once the engine reaches closed loop, the O2 sensor should begin switching rapidly between rich and lean voltages 2-3 times per second. If for some reason the O2 sensor doesn’t switch properly or “sticks”, P0154 BMW may set. This code indicates the O2 sensor isn’t operating.

Symptoms

Possible sumptoms of OBD code P0154 BMW
Symptoms of a P0154 BMW code may include: MIL (Malfunction Indicator Lamp) illumination Other codes indicating rich or lean condition may be present Poor idle, won’t idle Misfire at idle or at highway speed Engine may blow black smoke at tailpipe Fuel economy may decrease May start and stall

Causes

Possible causes of OBD code P0154 BMW
Potential causes of a P0154 BMW code include: Faulty bank 2,1 Oxygen sensor Holes in exhaust near oxygen sensor Short to voltage or ground on signal circuit Open or high resistance in signal circuit Wiring harness chafing/rubbing on exhaust components Water/oil intrusion at O2 sensor connector Broken lock or loose terminals on O2 sensor connector Oil/coolant fouled oxygen sensor

Possible Solutions

First start the engine and bring it up to operating temperature and ensure the engine reaches closed loop. Then, using the live data function on a scan tool, observe the Bank 2,1 oxygen sensor voltage reading. Is it switching properly? If so, the problem may be an intermittently bad sensor or more likely a wiring problem. Visually check the O2 sensor wiring and repair as needed. Does the voltage for the Bank 2,1 oxygen sensor appear to be “stuck” and not moving? If so, increase idle speed for 30 seconds or so. If the sensor begins switching after a period of elevated idle, visually check the exhaust for holes or rust near the O2 sensor that could be affecting the voltage reading If the exhaust checks out, suspect the sensor to be sluggish and replace it. If the Bank 2,1 oxygen sensor appears to be not switching, turn the engine off, and unplug the Bank 2,1 oxygen sensor. With KOEO (Key on engine off) jumper the O2 sensor signal wire to the ground wire. Now the voltage reading should be low (about 0.1v). If it is, then check for a bad connection at the O2 sensor connector. Repair as necessary. If no bad connection is found, replace the O2 sensor and re-check. If when you jumper the signal wire to the ground wire the voltage reading isn’t low (about 0.1v), remove the jumper wire. Now check for voltage at the O2 sensor signal wire. It should have, with KOEO and O2 sensor unplugged, roughly 0.5 volts. If it does, check also for a good ground to the sensor as well. Repair as necessary Check for loose connections, water intrusion at PCM connector, etc. If you have no 0.5 volt reference voltage, unplug the PCM connector and ohm the signal circuit and ground circuits. There should be no resistance nor any voltage. Repair excessive resistance. If you still have no 0.5 volt reference voltage, recheck at the PCM connector. It may be necessary to clip the signal wire to eliminate the possibility of a short or open somewhere. If you now have reference voltage present coming out of the PCM, fix open/short in signal circuit. If you have no reference voltage coming out of the PCM, the PCM will have to be diagnosed for a fault. It may be the problem.


The OBD2 Code Information Be Applicable For BMW:

2013 BMW X6 M50d,2013 BMW X6,2013 BMW X5 eDrive Concept,2013 BMW X5 Security Plus Concept,2013 BMW X5 M50d,2013 BMW X4 Concept,2013 BMW X1,2013 BMW Pininfarina Gran Lusso Coupe,2013 BMW M6 Coupe US-Version,2013 BMW M6 Coupe,2013 BMW M6 Convertible,2013 BMW M5 US-Version,2013 BMW M550d xDrive Touring,2013 BMW M550d xDrive,2013 BMW M4 Coupe Concept,2013 BMW M135i,2013 BMW Active Tourer Outdoor Concept,2013 BMW 7 ActiveHybrid,2013 BMW 750Li,2013 BMW 7-Series,2013 BMW 640i Gran Coupe,2013 BMW 640d xDrive Coupe,2013 BMW 6-Series Gran Coupe UK Version,2013 BMW 6-Series Gran Coupe,2013 BMW 5 ActiveHybrid,2013 BMW 4-Series Coupe Concept,2013 BMW 3 ActiveHybrid,2013 BMW 3-Series Touring,2013 BMW 3-Series Long Wheelbase,2013 BMW 1-Series 3-door,2012 BMW i8 Spyder Concept,2012 BMW i3 Coupe Concept,2012 BMW Zagato Roadster Concept,2012 BMW Zagato Coupe Concept,2012 BMW M5 UK Version,2012 BMW M5,2012 BMW M3 DTM Champion Edition,2012 BMW M3 CRT,2012 BMW M135i Concept,2012 BMW Active Tourer Concept,2012 BMW 650i Convertible,2012 BMW 640d Coupe,2012 BMW 6-Series Coupe,2012 BMW 6-Series Convertible,2012 BMW 3-Series,2012 BMW 1-Series Urban Line,2012 BMW 1-Series Sport Line,2012 BMW 1-Series Coupe,2012 BMW 1-Series Convertible,2012 BMW 1-Series,2011 BMW i8 Concept,2011 BMW i3 Concept,2011 BMW Z4,2011 BMW X5,2011 BMW X3 xDrive35i,2011 BMW X3 xDrive20d,2011 BMW X3,2011 BMW X1 xDrive28i,2011 BMW M5 Concept,2011 BMW M3 Pickup Concept,2011 BMW M3 GTS,2011 BMW M3 Frozen Gray,2011 BMW ConnectedDrive Concept,2011 BMW ActiveE Concept,2011 BMW 750Li,2011 BMW 5-Series Touring,2011 BMW 5-Series Long-Wheelbase,2011 BMW 5-Series,2011 BMW 335is Coupe,2011 BMW 328 Hommage Concept,2011 BMW 3-Series Coupe,2011 BMW 3-Series Convertible,2011 BMW 1-Series M Coupe US Version,2011 BMW 1-Series M Coupe UK Version,2011 BMW 1-Series M Coupe MotoGP Safety Car,2011 BMW 1-Series M Coupe,2010 BMW Z4 UK Version,2010 BMW Z4 GT3,2010 BMW Z4,2010 BMW X6 M,2010 BMW X6 ActiveHybrid,2010 BMW X5 M,2010 BMW X1,2010 BMW Scooter C Concept,2010 BMW M3,2010 BMW Gran Coupe Concept,2010 BMW ActiveE Concept,2010 BMW 7 ActiveHybrid,2010 BMW 760Li,2010 BMW 7-Series High Security,2010 BMW 6-Series Coupe Concept,2010 BMW 5-Series Gran Turismo,2010 BMW 5-Series ActiveHybrid Concept,2010 BMW 320d EfficientDynamics,2010 BMW 135i Coupe,2010 BMW 135i Convertible,2009 BMW X6 UK Version,2009 BMW X6,2009 BMW X5 xDrive35d BluePerformance,2009 BMW X5 Security Plus,2009 BMW X5 Security,2009 BMW X3 Limited Sport Edition,2009 BMW M3 Saloon UK Version,2009 BMW M3 Race Version,2009 BMW M3 Convertible UK Version,2009 BMW M3 Convertible,2009 BMW EfficientDynamics Concept,2009 BMW 750Li,2009 BMW 730d,2009 BMW 7-Series UK Version,2009 BMW 7-Series,2009 BMW 5-Series Gran Turismo Concept,2009 BMW 335d BluePerformance,2009 BMW 3-Series UK Version,2009 BMW 3-Series Touring UK Version,2009 BMW 3-Series Touring,2009 BMW 3-Series,2009 BMW 1-Series Convertible UK Version,2008 BMW X5 M-Package,2008 BMW X1 Concept,2008 BMW M5 Touring,2008 BMW M3 Sedan US-Version,2008 BMW M3 Sedan,2008 BMW M3 Coupe US-Version,2008 BMW M3 Coupe UK Version,2008 BMW M3 Coupe,2008 BMW M1 Concept,2008 BMW M-Zero Concept,2008 BMW GINA Light Visionary Model Concept,2008 BMW EfficientDynamics Concept,2008 BMW Coupe Range,2008 BMW 7-Series ActiveHybrid Concept,2008 BMW 650i Convertible,2008 BMW 635d Coupe,2008 BMW 530i,2008 BMW 5-Series Touring,2008 BMW 5-Series Security,2008 BMW 5-Series,2008 BMW 135i Coupe,2008 BMW 128i Convertible,2008 BMW 1-Series Range,2008 BMW 1-Series Coupe,2008 BMW 1-Series Cabrio,2008 BMW 1-Series 5-door,2008 BMW 1-Series 3-door,2007 BMW X6 Concept,2007 BMW X6 ActiveHybrid Concept,2007 BMW X5 4.8i,2007 BMW X5 3.0d,2007 BMW X3,2007 BMW M6 Convertible Neiman Marcus,2007 BMW M6 Cabrio,2007 BMW M5,2007 BMW M3 Concept,2007 BMW Hydrogen 7,2007 BMW Concept CS,2007 BMW 530Li,2007 BMW 335i Coupe,2007 BMW 335i Convertible,2007 BMW 1-Series tii Concept,2006 BMW Z4 Roadster,2006 BMW Z4 M Roadster,2006 BMW Z4 M Coupe UK version,2006 BMW Z4 M Coupe,2006 BMW Z4 Coupe,2006 BMW Mille Miglia Coupe Concept,2006 BMW Art Car Collection,2006 BMW 7 Series High Security,2006 BMW 760Li,2006 BMW 750i,2006 BMW 750Li with Shadow Line,2006 BMW 750Li,2006 BMW 330i,2006 BMW 325i Touring,2006 BMW 320si E90 WTCC,2006 BMW 320si,2006 BMW 320d Touring,2006 BMW 320d,2005 BMW Z4 Coupe Concept,2005 BMW X5,2005 BMW X3 EfficientDynamics Concept,2005 BMW X3,2005 BMW M6,2005 BMW M5,2005 BMW H2R,2005 BMW 630i,2005 BMW 545i Touring,2005 BMW 530xi Touring,2005 BMW 530xi,2005 BMW 530d Touring,2005 BMW 330i M-Package,2005 BMW 320d Touring,2005 BMW 130i M-Package,2005 BMW 130i,2005 BMW 120i UK Version,2005 BMW 120i,2005 BMW 120d,2004 BMW X5 4.8is,2004 BMW X5 4.4i,2004 BMW X3 3.0i,2004 BMW X3 2.0d,2004 BMW H2R Hydrogen Racecar,2004 BMW Concept M5,2004 BMW 645Ci Convertible,2004 BMW 645Ci,2004 BMW 5 Series,2004 BMW 530i,2004 BMW 530d,2004 BMW 330Ci Coupe,2004 BMW 330Ci Convertible,2004 BMW 330Cd Coupe,2004 BMW 325Ci Coupe,2004 BMW 320Cd Convertible,2004 BMW 318Ci Convertible,2003 BMW Z4 2.5i,2003 BMW Z4,2003 BMW M3 CSL,2003 BMW 760Li E66,2003 BMW 325ti Compact,2003 BMW 3-Series Compact,2002 BMW xActivity Concept,2002 BMW X5 4.6is,2002 BMW CS1 Concept,2002 BMW 7 Series,2002 BMW 760i,2002 BMW 760Li Yachtline Concept,2002 BMW 740d,2002 BMW 730d,2002 BMW 3-Series Touring,2002 BMW 3-Series,2001 BMW Z8

 

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