| • | 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. | 
Circuit  | Short to Ground  | Open/High Resistance  | Short to Voltage  | Signal Performance  | 
|---|---|---|---|---|
IAT Sensor Signal  | P0095 03, P0097  | P0095 07, P0098  | P0095 07, P0098*  | P0110  | 
Low Reference  | --  | P0095 07, P0098  | P0095 07, P0098*  | P0110  | 
* Internal ECM or sensor damage may occur if the circuit is shorted to B+  | ||||
The intake air temperature (IAT) sensor 2 is an integral part of the turbocharger pressure 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 DTCs run continuously once the above conditions are met. | 
The ECM detects that the IAT sensor 2 is less than 160 mV for greater than 0.5 seconds.
The ECM detects that the IAT sensor 2 parameter is greater than 4.9 volts for greater than 0.5 seconds.
DTCs P0095, P0097, and P0098 are Type B DTCs.
DTCs P0095, P0097, and P0098 are Type B DTCs.
| • | 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. | 
Measure and record the resistance between the IAT signal circuit terminal 3 and the low reference circuit terminal 4 at various ambient temperatures. Compare those measurements to the Temperature Versus Resistance table and verify that the resistance is within 5 percent of the specification.
| ⇒ | If not within the specified range, replace the turbocharger pressure sensor | 
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for ECM replacement, setup, and programming |