Description
OBD-II Trouble Code Description for P0112 Infiniti
Intake Air Temperature Sensor 1 Circuit Low
What does this mean?
OBD2 Code P0112 Infiniti definition:
The IAT (intake air temperature) sensor simply measures the temperature of air that is entering the engine. Intake air temperature is important because the higher the intake air, the higher the combustion temperatures. High combustion temperatures result in increased Nox (Nitrogen oxides) emissions. To keep these higher temps from causing increased combustion temps, the intake air tubing should be intact, allowing the engine to “breathe” air that isn’t sampled from the engine compartment. The IAT measures air temp by using a thermistor, or a thermometer of sorts. The thermistor is supplied 5 volts reference voltage from the PCM (powertrain control module) and a ground. Usually, when the air temperature is cold the resistance in the thermistor is high and when the air temperature is warmer, the resistance decreases. This change in resistance changes the 5 V reference from the PCM, thereby informing the PCM of the temperature of incoming air. If the PCM notices that the incoming air temp is unusually high, say, 300 degrees, when the engine temp is still relatively low, it will set a P0112 Infiniti.
Symptoms
Possible sumptoms of OBD code P0112 Infiniti
There may be no noticeable symptoms of a P0112 Infiniti code other than an MIL (Malfunction Indicator Lamp). However, a emissions test may reveal higher Nox readings depending on the type of IAT failure. Or the engine may ping under load, depending on the type of IAT failure.
Causes
Possible causes of OBD code P0112 Infiniti
No reference voltage to the IAT sensor due to an open wire Excessively high intake air temperatures Short to ground on signal circuit Damaged IAT connector Bad PCM
Possible Solutions
Hook up your scan tool or code reader and read the IAT reading. With a cold engine, the IAT should roughly match the coolant reading, since both will read ambient temperature. If the IAT is reading excessively high, check the IAT connector for damage. If you find none, unplug the IAT sensor and recheck the reading. It should now read the minimum, around -20 deg. If it does, then replace the IAT sensor. But, if the reading is still high, unplug the sensor and check for resistance across the two wiring harness terminals. If there is infinite resistance, then the PCM itself is bad. If the resistance isn’t infinite, then check and repair the short to ground on the signal circuit.
The OBD2 Code Information Be Applicable For Infiniti:
,2013 Infiniti M35h GT,2013 Infiniti JX,2013 Infiniti FX,2011 Infiniti QX,2011 Infiniti M35h,2011 Infiniti M,2011 Infiniti JX Concept,2011 Infiniti IPL G Coupe,2011 Infiniti EX30d,2009 Infiniti G37,2009 Infiniti FX50,2009 Infiniti FX37,2009 Infiniti FX35,2009 Infiniti Essence Concept,2009 Infiniti EX37,2008 Infiniti QX56,2008 Infiniti M45x,2008 Infiniti M45s,2008 Infiniti G37 Coupe,2008 Infiniti EX35,2007 Infiniti G35 Sedan,2007 Infiniti EX Concept,2006 Infiniti QX56,2006 Infiniti Q45,2006 Infiniti M45,2006 Infiniti M35x,2006 Infiniti M35,2006 Infiniti FX45,2005 Infiniti Q45,2005 Infiniti G35,2005 Infiniti FX45,2004 Infiniti QX56,2004 Infiniti M45 Concept,2004 Infiniti I35,2003 Infiniti QX4,2003 Infiniti Q45,2003 Infiniti M45,2003 Infiniti I35,2003 Infiniti G35,2003 Infiniti FX45,2003 Infiniti FX35
Note:
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