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Home >> Chevrolet >> 2005 >> Epica LS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - 2.5L (LBK) - DTC P0030 To DTC P0154 >> DTC P0111 >> Circuit Description

Circuit Description

The intake air temperature (IAT) sensor is a variable resistor that measures the temperature of the air entering the engine. The IAT sensor has a signal circuit and a low reference circuit. The engine control module (ECM) supplies 5 volts to the IAT signal circuit and a ground for the IAT low reference circuit. If the ECM detects that the IAT signal voltage is not changing due to engine running conditions, this DTC sets.

The following table illustrates the difference between temperature, resistance, and voltage:

IAT IAT Resistance IAT Signal Voltage
Cold High High
Warm Low Low
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