P00AC IAT Sensor 1 Circuit Low Input Bank 2

Description and meaning of DTC p00ac

This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles. Although generic, the specific repair steps may vary depending on make/model. The IAT (intake air temperature) sensor simply measures the temperature of air thatis entering the engine. Intake air temperature is important because the higher theintake air, the higher the combustion temperatures. High combustion temperaturesresult in increased Nox (Nitrogen oxides) emissions. To keep these higher tempsfrom causing increased combustion temps, the intake air tubing should be intact,allowing the engine to "breathe" air that isn't sampled from the enginecompartment. The IAT sensor measures air temp by using a thermistor, or a thermometer ofsorts. The thermistor is supplied 5 volts reference voltage from the PCM(powertrain control module) and a ground. Usually, when the air temperature is coldthe resistance in the thermistor is high and when the air temperature is warmer, theresistance decreases. This change in resistance changes the 5 V reference from thePCM, thereby informing the PCM of the temperature of incoming air. If the PCMnotices that the incoming bank 2 air temp sensor is unusually high, say, 300 degrees, when theengine temp is still relatively low, it will set a P00AC. Bank 2 is the side of the engine that does not contain cylinder #1. Related Bank 2 IAT sensor circuit trouble codes:P00AA Intake Air Temperature Sensor 1 Circuit Bank 2P00AB Intake Air Temperature Sensor 1 Circuit Range/Performance Bank 2P00AD Intake Air Temperature Sensor 1 Circuit High Bank 2P00AE Intake Air Temperature Sensor 1 Circuit Intermittent/Erratic Bank 2

p00ac diagnostic trouble code symptoms

There may be no noticeable symptoms of a P00AC code other than an MIL (MalfunctionIndicator Lamp). However, a emissions test may reveal higher Nox readings dependingon the type of IAT failure. Or the engine may ping under load, depending on thetype of IAT failure.

DTC p00ac - possible causes

Usually the P00AC is caused by a bad bank 2 IAT sensor (internally shorted or open or otherwise damaged),but it could also be:No reference voltage to the bank 2 IAT sensor due to an open wireExcessively high intake air temperaturesShort to ground on signal circuitDamaged IAT connectorBad PCM

How to fix OBD-II diagnostic trouble code p00ac

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 ambienttemperature. If the IAT #2 is reading excessively high, check the IAT connector fordamage. If you find none, unplug the IAT sensor and recheck the reading. It shouldnow read the minimum, around -20 deg. If it does, then replace the IAT sensor #2. But, if the reading is still high, unplug the sensor and check for resistance acrossthe two wiring harness terminals. If there is infinite resistance, then the PCMitself is bad. If the resistance isn't infinite, then check and repair the shortto ground on the signal circuit.

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