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Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> External Pages >> Different car >> Section 369 (Engine Controls And Fuel - 5.3L, 6.0L & 6.2L - DTC P0010 Through DTC P0442) >> Diagnostic Information and Procedures >> DTC P0112 or P0113 >> Circuit Description

Circuit Description

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The intake air temperature (IAT) sensor is integrated with the mass air flow (MAF) sensor. It 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.

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

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