Diagnostic Instructions

•	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.

DTC Descriptor

DTC P0096

Intake Air Temperature (IAT) Sensor 2 Performance

DTC P0111

Intake Air Temperature (IAT) Sensor 1 Performance

Diagnostic Fault Information

IAT Sensor 1

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
IAT Sensor 1 Signal	P0112	P0113	P0113	P0111
Low Reference	-	P0113	P0113, P0114	P0111

IAT Sensor 2

Circuit	Short to Ground	Open /High Resistance	Short to Voltage	Signal Performance
IAT Sensor 2 Signal	P0097	P0098	P0098	P0096
Low Reference	-	P0098	P0098	P0096

Typical Scan Tool Data

IAT Sensor 1

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Engine running Parameter Normal Range: Varies with ambient temperature
IAT Sensor 1 Signal	150°C (302°F)	-40°C (-40°F)	-40°C (-40°F)*
Low Reference	-	-40°C (-40°F)	-40°C (-40°F)*
*Internal ECM or sensor damage may occur if the circuit is shorted to B+

IAT Sensor 2

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Engine running Parameter Normal Range: Varies with ambient temperature
IAT Sensor 2	143°C (289°F)	-40°C (-40°F)	-40°C (-40°F)*
Low Reference	-	-40°C (-40°F)	-40°C (-40°F)*
*Internal ECM or sensor damage may occur if the circuit is shorted to B+

Circuit/System Description

IAT sensor 1 is an integral part of the mass air flow (MAF) sensor; it measures the temperature of the air entering the air induction system. IAT sensor 2 is an integrated part of the intake manifold pressure and air temperature sensor. It measures the temperature of the air after the turbocharger and the charge air cooler (CAC), and before it enters the engine intake manifold. The engine control module (ECM) supplies 5 V to the IAT sensor 1 and 2 signal circuits, and seperate grounds for their low reference circuits. At engine start up, the ECM monitors the engine coolant temperature (ECT) sensor, the IAT sensor 1, and the IAT sensor 2 signals for a voltage that is not within a calibrated range of each other.

The intake air temperature (IAT) sensor 1 and the IAT sensor 2 are variable resistors. When the sensor is cold, the sensor resistance is high. When the air temperature increases, the sensor resistance decreases. With high sensor resistance, the ECM detects a high voltage on the signal circuit. With lower sensor resistance, the ECM detects a lower voltage on the sensor signal circuit.

Conditions for Running the DTCs

•	DTCs P0096, P0097, P0098, P0111, P0112, P0113, P0116, P0117, P0118, P0119, and P0128 are not set.

•	The ignition has been OFF for at least 8 hours.

•	DTCs P0096 and P0111 run once per key cycle at engine start, within the enabling conditions.

Conditions for Setting the DTCs

P0096

At engine start, the ECM determines the absolute temperature difference between the IAT Sensor 1 signal and the IAT Sensor 2 signal is equal to or more than 20°C (36°F)

AND

At engine start, the ECM determines the absolute temperature difference between the ECT signal and the IAT Sensor 1 signal is more than the absolute temperature difference between the ECT signal and the IAT Sensor 2 signal.

P0111

At engine start, the ECM determines the absolute temperature difference between the IAT Sensor 1 signal and the IAT Sensor 2 signal is equal to or more than 20°C (36°F)

AND

At engine start, the ECM determines the absolute temperature difference between the ECT signal and the IAT Sensor 2 signal is more than the absolute temperature difference between the ECT signal and the IAT Sensor 1 signal.

Action Taken When the DTCs Set

DTC P0096 and P0111 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTC P0096 and P0111 are Type B DTCs.

Diagnostic Aids

•

An IAT sensor that is skewed lower at various ambient temperatures, due to greater resistance than is normal, can widen the spread between the sensors and cause a DTC to set. Measure and record the resistance of the IAT sensor 1 and IAT sensor 2 at various ambient temperatures, and then compare those measurements to the Temperature Versus Resistance (IAT 2) Temperature Versus Resistance (ECT) Temperature Versus Resistance (IAT) IAT and IAT 2 tables.

•	Inspect both IAT sensors' terminals, for corrosion or a poor connection.

•	The Intake Manifold Pressure and Air Temperature Sensor may also be refered to as Turbocharger Boost Sensor or Intake Air Pressure and Temperature Sensor.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Note
•	Perform Step 1 of this verification procedure only if the ignition has been OFF for 8 hours or more.
•	The vehicle sitting in direct sun light or having the block heater ON will skew the results.

1.	Ignition ON, observe the following scan tool parameters. The readings should be within 19°C (34°F) of each other.

•

IAT Sensor 1

•

IAT Sensor 2

•

Start-Up ECT Sensor

2.	Engine idling, verify the appropriate scan tool parameters' are within the specified ranges. The readings depend on the current ambient temperature and the vehicle operating conditions.

•

-39 to +149°C (-38 to +300°F); IAT Sensor 1

•

-39 to +142°C (-38 to +288°F); IAT Sensor 2

•

-39 to +120°C (-38 to +248°F); ECT

3.	Operate the vehicle within the Conditions for Running the DTC to verify that the DTC has not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

Note

You must perform the circuit/system verification before proceeding with circuit/system testing.

1.	Verify that DTCs P0097, P0098, P0112, P0113, P0116, P0117, P0118, P0119, or P0128 are not set.

2.	If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.

3.	Ignition OFF, disconnect the harness connector at the appropriate IAT sensor as determined in the Circuit/System Verification.

4.	Ignition OFF, all vehicle systems OFF. This may take up to 2 minutes; test for less than 5 Ω between the appropriate low reference circuit and ground.

•

IAT 1; low reference circuit terminal 4 or D

•

IAT 2; low reference circuit terminal 1 or A

5.	If greater than the specified range, test the appropriate low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.

6.	Ignition ON, verify the appropriate scan tool IAT sensor parameter is colder than -39°C (-38°F).

7.	If warmer than the specified range, test the appropriate signal circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.

8.	Install a 3 A fused jumper wire between the appropriate signal circuit and the appropriate low reference circuit.

•

IAT 1; signal circuit terminal 5 or E, low reference circuit terminal 4 or D

•

IAT 2; signal circuit terminal 2 or B, low reference circuit terminal 1 or A

9.	Verify the appropriate scan tool IAT sensor parameter is warmer than:

•

IAT 1; 149°C (300°F)

•

IAT 2; 142°C (288°F)

10.	If colder than the specified range, test the appropriate signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 ECM.

11.	If all circuits test normal, test or replace appropriate IAT sensor.

Component Testing

Measure and record the resistance of the MAF/IAT sensor and IAT sensor 2 at various ambient temperatures, and then compare those measurements to the Temperature Versus Resistance (IAT 2) Temperature Versus Resistance (ECT) Temperature Versus Resistance (IAT) IAT and IAT 2 tables.

Repair Instructions

•	Mass Airflow Sensor Replacement

•	Intake Air Pressure and Temperature Sensor Replacement for Intake Manifold Pressure and Air Temperature Sensor

•	Control Module References for ECM replacement, setup, and programming

Repair Verification

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.