Description
OBD-II Trouble Code Description for P0112 Lexus
Intake Air Temperature Sensor 1 Circuit Low
What does this mean?
OBD2 Code P0112 Lexus 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 Lexus.
Symptoms
Possible sumptoms of OBD code P0112 Lexus
There may be no noticeable symptoms of a P0112 Lexus 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 Lexus
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 Lexus:
2013 Lexus RX 450h F Sport,2013 Lexus RX 450h,2013 Lexus RX 350 F Sport,2013 Lexus RX 350,2013 Lexus LX 570,2013 Lexus LS EU-Version,2013 Lexus LS 600h L,2013 Lexus LS 460 F Sport,2013 Lexus LS 460,2013 Lexus LF-NX Concept,2013 Lexus GS 450h F Sport,2013 Lexus GS 450h,2013 Lexus GS 350 F Sport,2013 Lexus GS 350,2013 Lexus GS 250,2013 Lexus ES 300h,2013 Lexus ES350,2012 Lexus LF-LC Concept,2012 Lexus LF-CC Concept,2011 Lexus LFA,2011 Lexus LF-Gh Concept,2011 Lexus IS 350 F Sport,2011 Lexus IS 350,2011 Lexus CT 200h,2010 Lexus SC 430,2010 Lexus RX 450h,2010 Lexus RX 350,2010 Lexus LS 600h,2010 Lexus LS 460 Sport,2010 Lexus LS 460 L,2010 Lexus IS250C,2010 Lexus HS 250h,2010 Lexus GX 460,2010 Lexus GS 460,2010 Lexus GS 450h,2010 Lexus GS 350,2010 Lexus ES 350,2009 Lexus SC430,2009 Lexus LS,2009 Lexus LS460,2009 Lexus LF-Ch,2009 Lexus IS 350,2009 Lexus GX 470,2009 Lexus GS 460,2009 Lexus GS 450h,2009 Lexus GS 350,2008 Lexus LX 570,2008 Lexus LS 600h L,2007 Lexus LS,2007 Lexus LF,2006 Lexus SC,2006 Lexus IS350,2006 Lexus GS,2005 Lexus RX400h,2005 Lexus LFA Concept,2005 Lexus ES330,2004 Lexus RX330,2004 Lexus LS430
Note:
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