Pontiac P0112 Intake Air Temperature Circuit Low Input

Description

OBD-II Trouble Code Description for P0112 Pontiac

Intake Air Temperature Sensor 1 Circuit Low

What does this mean?

OBD2 Code P0112 Pontiac 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 Pontiac.

Symptoms

Possible sumptoms of OBD code P0112 Pontiac
There may be no noticeable symptoms of a P0112 Pontiac 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 Pontiac
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.

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The OBD2 Code Information Be Applicable For Pontiac:

2010 Pontiac G8,2009 Pontiac G8,2009 Pontiac G6 ,2009 Pontiac G3,2008 Pontiac G8,2007 Pontiac Solstice SD-290 Concept,2007 Pontiac Solstice GXP,2007 Pontiac G6 GXP Show Car,2006 Pontiac Torrent,2006 Pontiac Solstice,2006 Pontiac Montana SV6,2006 Pontiac GTO,2006 Pontiac G6 GTP Coupe,2006 Pontiac G6 GTP Convertible,2005 Pontiac Vibe GT,2005 Pontiac Montana SV6,2005 Pontiac Grand Prix,2005 Pontiac Grand Am GT Coupe,2005 Pontiac GTO,2005 Pontiac G6 GT,2004 Pontiac Grand Prix GTP,2004 Pontiac Grand Am GXP,2004 Pontiac GTO 5.7,2004 Pontiac GTO,2004 Pontiac Bonneville GXP,2004 Pontiac Aztek Rally,2003 Pontiac Vibe GT,2003 Pontiac Vibe,2003 Pontiac Sunfire Coupe,2003 Pontiac Montana Thunder,2003 Pontiac Grand Prix,2003 Pontiac Grand Am SE Sedan,2003 Pontiac G6 Concept,2003 Pontiac Aztek,2002 Pontiac Sunfire GXP,2002 Pontiac Sunfire American Tuner,2002 Pontiac Solstice Concept,2002 Pontiac REV Concept,2002 Pontiac Grand Prix GXP,2002 Pontiac Grand Prix G-Force Concept,2002 Pontiac Firebird Trans Am Edition,2001 Pontiac Vibe GT,2001 Pontiac Vibe,2001 Pontiac Sunfire HO,2001 Pontiac Sunfire Accessorized,2001 Pontiac Montana,2001 Pontiac Grand Prix

 

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