| • | 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  | 
|---|---|---|---|---|
Signal  | P0097 12  | P0098 11  | P0098 11  | --  | 
Low Reference  | --  | P0098 11  | P0098 11  | --  | 
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 V 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 s.
The ECM detects that the IAT sensor 2 parameter is greater than 4.9 V for greater than 0.5 s.
DTCs P0097 and P0098 are Type B DTCs.
DTCs P0097 and P0098 are Type B DTCs.
| • | If the engine has sat overnight, the IAT sensor and the engine coolant temperature (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 may set a DTC. | 
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module (ECM). | 
| ⇒ | If less than the specified range, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module (ECM). | 
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module (ECM). | 
Measure and record the resistance between the IAT signal circuit terminal 2 and the low reference circuit terminal 1at various ambient temperatures. Compare those measurements to the Temperature Versus Resistance table and verify that the resistance is within 5% of the specification.
If not within the specified range, replace the B111 Turbocharger Boost Pressure Sensor.
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Link | 
| • | Engine Control Module Replacement for ECM replacement, setup, and programming |