| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. | 
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. | 
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. | 
The intake air temperature (IAT) sensor 1 is an integral part of the mass air flow (MAF) sensor. The IAT sensor is a variable resistor that measures the temperature of the intake air. The engine control module (ECM) supplies 5 volts to the IAT signal circuit and supplies a ground to the 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  | 
| • | The ignition is ON or the engine is running. | 
| • | The ignition voltage is greater than 8.5 volts. | 
| • | The DTCs run continuously once the above conditions are met. | 
The ECM detects that an IAT 1 circuit is open, shorted to ground or voltage.
The ECM detects that the duty cycle of IAT 1 signal is greater than 90 percent.
The ECM detects that the duty cycle of IAT 1 signal is less than 10 percent.
DTC P0110 is a Type B DTC.
DTC P0110 is a Type B DTC.
| • | If the engine has sat overnight, the IAT sensor and the ECT sensor values should display within 3°C (5°F). | 
| • | High resistance on either the IAT sensor signal circuit or the IAT sensor low reference circuit could set a DTC. | 
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance, or for a short to voltage. If the circuit tests normal, replace the ECM. | 
| ⇒ | If less than the specified range, test the signal circuit for an open or a short to ground. If the circuit tests normal, replace the ECM. | 
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM. | 
Test and record the resistance between the signal circuit terminal 3 and the low reference circuit terminal 2 at various ambient temperatures. Compare those measurements to the Temperature Versus Resistancetable and verify that the resistance is within 5 percent of the specification.
| ⇒ | If not within the specified range, replace the MAF/IAT sensor | 
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for engine control module replacement, setup, and programming | 
Ignition ON, observe the scan tool DPF soot mass parameter. The parameter should be less than 24 grams.
| ⇒ | If greater than the specified range, perform a DPF service regeneration. Refer to Exhaust Particulate Filter Cleaning. |