Description
OBD-II Trouble Code Description for P0111 Mercedes
IAT Circuit Malfunction
What does this mean?
OBD2 Code P0111 Mercedes definition:
The IAT (Intake Air Temperature) sensor is a thermistor that varies resistance based upon the temperature of the engine intake air. Usually a two wire sensor. One wire is supplied 5 Volt from the PCM (Powertrain Control Module) and the other is a ground. The PCM monitors the change in the 5 Volt supplied to determine air temperature. When the intake air is cold, the resistance is high, resulting in a high signal voltage. When the intake air is warm, the reistance is low, resulting in a low signal voltage. This code means that the PCM saw a larger-than-normal change in a shorter-than-expected time on the IAT signal circuit.
Symptoms
Possible sumptoms of OBD code P0111 Mercedes
Since this code is likely pointing to an intermittent problem on the IAT circuit, there may not be any symptoms at present. However, the MIL will likely be on. The car MAY exhibit some drivability problems, but it is more likely that there will be no noticeable symptoms to the driver.
Causes
Possible causes of OBD code P0111 Mercedes
a bad IAT sensor an open in the signal or ground circuit a short to ground on the signal circuit poor connection at sensor or PCM
Possible Solutions
If there are other IAT codes present, diagnose them first. If not, then, using a scan tool verify the IAT voltage with KOEO (Key on engine off). If, on a cold engine it reads the same as the CTS (Coolant temperature sensor), then the problem is intermittent. But if the IAT reading isn’t the same as the CTS refer to diagnostic procedure for P0110 Mercedes. If your scan tool has a freeze frame failure records feature, use it to see what the IAT reading was at the time of the failure. If the reading was at negative 30 or so degrees F (indicating it was at the extreme coldest reading), then there was an intermittent high resistance reading on the IAT signal circuit. Check for an open ground on the ground circuit and signal circuit. If they are OK, try raising and lowering the temperature of the IAT sensor artificially. Do this by removing the IAT and putting it in a freezer and then applying heat with a heat gun (be careful not to apply too much heat to the IAT with the heat gun or it’ll melt the sensor). Watch the resistance change using an ohmmeter attached to each terminal. It should vary smoothly with no sudden jumps. If the reading jumps suddenly, then repace the IAT sensor. However if the freeze frame reading was at the highest extreme (above 250 deg. F) then there was an intermittent low resistance on the signal circuit. Check for a short to ground on the signal circuit. If it appears OK, then do the above artificial heat test and replace the IAT as necessary. If the problem can’t be duplicated, use a voltmeter to watch the signal voltage as you “wiggle” test the wiring harness. Watch for a sudden change in voltage indicating a short or open. Replace IAT as necessary. This is a pretty simple code and it only really looks for extremely short changes that are relatively high in voltage. It’s usually the sensor that is bad unless the vehicle is extremely old, in which case there may be harness problems.
The OBD2 Code Information Be Applicable For Mercedes-Benz:
2013 Mercedes-Benz SLS AMG GT,2013 Mercedes-Benz SL65 AMG,2013 Mercedes-Benz SL550,2013 Mercedes-Benz SL500,2013 Mercedes-Benz SL-Class,2013 Mercedes-Benz GLK350 4Matic,2013 Mercedes-Benz GLK-Class,2013 Mercedes-Benz GL63 AMG,2013 Mercedes-Benz GL-Class,2013 Mercedes-Benz G63 AMG 6×6 Concept,2013 Mercedes-Benz G63 AMG,2013 Mercedes-Benz G550,2013 Mercedes-Benz G350 Bluetec,2013 Mercedes-Benz G-Class,2013 Mercedes-Benz E300 BlueTEC Hybrid,2013 Mercedes-Benz Citan,2013 Mercedes-Benz CLS Shooting Brake,2013 Mercedes-Benz A-Class AMG Sport,2013 Mercedes-Benz A-Class,2012 Mercedes-Benz SLS AMG Roadster,2012 Mercedes-Benz SLK55 AMG,2012 Mercedes-Benz SLK350,2012 Mercedes-Benz SLK250 CDI,2012 Mercedes-Benz SLK-Class,2012 Mercedes-Benz ML63 AMG,2012 Mercedes-Benz M-Class,2012 Mercedes-Benz E63 AMG Wagon,2012 Mercedes-Benz E63 AMG,2012 Mercedes-Benz CLS63 AMG,2012 Mercedes-Benz CLS550,2012 Mercedes-Benz CLS350 CDI,2012 Mercedes-Benz CLS-Class,2012 Mercedes-Benz C63 AMG,2012 Mercedes-Benz C-Class,2012 Mercedes-Benz B-Class,2011 Mercedes-Benz Vito,2011 Mercedes-Benz Viano,2011 Mercedes-Benz SLS AMG,2011 Mercedes-Benz S63 AMG,2011 Mercedes-Benz S600 Pullman Guard,2011 Mercedes-Benz R-Class,2011 Mercedes-Benz ML 63 AMG,2011 Mercedes-Benz G-Class,2011 Mercedes-Benz F125 Concept,2011 Mercedes-Benz E550 Cabriolet,2011 Mercedes-Benz E350 Cabriolet,2011 Mercedes-Benz E350 4Matic Wagon,2011 Mercedes-Benz E-Class L,2011 Mercedes-Benz E-Class Cabriolet,2011 Mercedes-Benz CL65 AMG,2011 Mercedes-Benz CL63 AMG,2011 Mercedes-Benz CL500,2011 Mercedes-Benz CL-Class,2011 Mercedes-Benz C-Class DR 520,2011 Mercedes-Benz B55 Concept,2011 Mercedes-Benz A-Class E-CELL,2011 Mercedes-Benz A-Class Concept,2010 Mercedes-Benz S65 AMG,2010 Mercedes-Benz S63 AMG,2010 Mercedes-Benz S400 BlueHYBRID,2010 Mercedes-Benz S-Class,2010 Mercedes-Benz ML450 Hybrid,2010 Mercedes-Benz GLK-Class,2010 Mercedes-Benz GL550,2010 Mercedes-Benz E63 AMG Estate,2010 Mercedes-Benz E63 AMG,2010 Mercedes-Benz E550 Coupe,2010 Mercedes-Benz E550,2010 Mercedes-Benz E350 Coupe,2010 Mercedes-Benz E350,2010 Mercedes-Benz E-Class,2010 Mercedes-Benz Biome Concept,2010 Mercedes-Benz B-Class F-Cell,2009 Mercedes-Benz SL65 AMG,2009 Mercedes-Benz SL63 AMG,2009 Mercedes-Benz SL-Class,2009 Mercedes-Benz ML 63 AMG,2009 Mercedes-Benz M-Class,2009 Mercedes-Benz G55 AMG,2009 Mercedes-Benz G-Class,2009 Mercedes-Benz CLS 63 AMG,2009 Mercedes-Benz CLS 280,2009 Mercedes-Benz CLC,2009 Mercedes-Benz B-Class,2009 Mercedes-Benz A-Class,2008 Mercedes-Benz SL,2008 Mercedes-Benz SLR,2008 Mercedes-Benz R-Class,2008 Mercedes-Benz CL65 AMG,2008 Mercedes-Benz C63 AMG,2008 Mercedes-Benz C-Class,2007 Mercedes-Benz S 63 AMG,2007 Mercedes-Benz S 600 Guard,2007 Mercedes-Benz S 500 4MATIC,2007 Mercedes-Benz S65 AMG,2007 Mercedes-Benz S550,2007 Mercedes-Benz R 63 AMG,2007 Mercedes-Benz G-Class,2007 Mercedes-Benz CL 63 AMG,2007 Mercedes-Benz CL 600,2007 Mercedes-Benz CL 500,2007 Mercedes-Benz CLS 63 AMG,2007 Mercedes-Benz CLS 350 CGI,2006 Mercedes-Benz SL 65 AMG,2006 Mercedes-Benz SL 600,2006 Mercedes-Benz SL 55 AMG,2006 Mercedes-Benz SL 500,2006 Mercedes-Benz SL 350,2006 Mercedes-Benz SLK 55 AMG SS,2006 Mercedes-Benz SL-Class,2006 Mercedes-Benz S-Class,2006 Mercedes-Benz R500,2006 Mercedes-Benz ML 63 AMG,2006 Mercedes-Benz ML500,2006 Mercedes-Benz ML350,2006 Mercedes-Benz GL 420 CDI,2006 Mercedes-Benz GL450,2006 Mercedes-Benz GL-Class,2006 Mercedes-Benz E 63 AMG,2006 Mercedes-Benz E-Class,2006 Mercedes-Benz CLK 63 AMG,2006 Mercedes-Benz B200 CDI,2006 Mercedes-Benz B150,2005 Mercedes-Benz SLK350,2005 Mercedes-Benz CLS500,2005 Mercedes-Benz CLK350,2005 Mercedes-Benz AClass
Note:
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