P0111
DTC P0096 or P0111
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions 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
Typical Scan Tool Data
Circuit/System Description
The sensors listed below are integrated within the mass air flow/multifunction intake air sensor:
* IAT sensor 1
* IAT sensor 2
* Humidity sensor
* MAF sensor
* BARO pressure sensor
The intake air temperature (IAT) sensor 1 is a variable resistor that changes the voltage on the engine control module (ECM) supplied 5 V signal circuit. The signal varies with inlet air temperature in the sensor bore and is displayed by the scan tool as °C (°F). The IAT sensor 2 and the humidity sensor share the same circuit. The IAT sensor 2 signal is displayed by the scan tool as Hertz (Hz) and °C (°F).
The sensors listed below share an ECM supplied 5 V reference circuit:
* IAT sensor 2
* Humidity sensor
* Barometric pressure (BARO) sensor
The sensors listed below share an ECM supplied low reference circuit:
* IAT sensor 1
* IAT sensor 2
* Humidity sensor
* Barometric pressure (BARO) sensor
Conditions for Running the DTCs
P0096 and P0111
* DTCs P0097, P0098, P0112, P0113, P0117, P0118, P0119, or P1682 are not set.
* The vehicle has been OFF at least 8 hours.
* Ignition 1 voltage is at least 11 V.
* These DTCs run once per ignition cycle when the enabling conditions are met.
Conditions for Setting the DTCs
P0096
* The ECM determines the absolute difference between IAT sensor 1 start-up temperature and the IAT sensor 2 start-up temperature is greater than 30°C (54°F).
AND
* The absolute difference between ECT start-up temperature and the IAT sensor 2 start-up temperature is greater or equal to the absolute difference between ECT start-up temperature and the IAT sensor 1 start-up temperature.
* This DTC runs once per ignition cycle when the enabling conditions are met.
P0111
* The ECM determines the absolute difference between IAT sensor 1 start-up temperature and the IAT sensor 2 start-up temperature is greater than 30°C (54°F).
AND
* The absolute difference between ECT start-up temperature and the IAT sensor 1 start-up temperature is greater or equal to the absolute difference between ECT start-up temperature and the IAT 2 start-up temperature.
* This DTC runs once per ignition cycle when the enabling conditions are met.
Action Taken When the DTCs Set
DTCs P0096 and P0111 are Type B DTCs.
Conditions for Clearing the DTCs
DTCs P0096 and P0111 are Type B DTCs.
Diagnostic Aids
The humidity sensor and the IAT sensor 2 signals are sent to the ECM on the same circuit. If the IAT Sensor 2 parameter displays the values: 10 Hz; -40°C (-40°F), and there are also Humidity Sensor DTCs, check for a circuit problem.
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Outside Rearview Mirror - Driver
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Special Tools
EN-38522 - Variable Signal Generator
For equivalent regional tools, refer to Special Tools Tools and Equipment.
Circuit/System Verification
Note: To minimize the effects of residual engine heat and sensor internal heating elements, perform Steps 1 and 2 of this verification procedure only if the ignition has been OFF for 8 hours or more.
1. Ignition ON.
2. Verify the following scan tool parameters are within 30°C (54°F) of each other.
* Start-Up IAT Sensor 1
* IAT Sensor 2
* IAT Sensor 3
• If not within 30°C (54°F)
Refer to Circuit/System Testing.
• If within 30°C (54°F)
3. Engine idling, verify the following scan tool parameters are between: -38 and +149°C (-36 and +300°F).
* IAT Sensor 1
* IAT Sensor 2
* IAT Sensor 3
• If not between: -38 and +149°C (-36 and +300°F)
Refer to Circuit System Testing.
• If between: -38 and +149°C (-36 and +300°F)
4. Operate the vehicle within the conditions for running the DTC to verify that the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.
5. Verify the DTCs do not set.
• If any of the DTCs set
Refer to Circuit/System Testing.
• If none of the DTCs set
6. All OK
Circuit/System Testing
Note: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
1. Verify none of the following conditions exist:
* A loose or disconnected charge air cooler hose or pipe
* A blocked or obstructed charge air cooler, including: after-market grill covers
* Any snow or ice build-up at the charge air cooler in cold climates
* Any mud or dirt build-up at the charge air cooler
* A restricted or collapsed air intake duct
* An intake manifold leak
* A MAP sensor seal that is leaking, missing, or damaged
* A restricted or collapsed air intake duct
* A misaligned or damaged air intake duct
* Any water intrusion in the induction system
* An Intake Manifold Resonator with a leaking seal, or a cracked or broken housing
• If a condition exists
Repair or replace component as appropriate.
• If no condition exists
2. Ignition OFF, disconnect the harness connector at the B75C Mass Air Flow/Multifunction Intake Air sensor.
3. Ignition OFF and all systems OFF. It may take up to for 2 minutes for all vehicle systems to power down. Test for less than 2 ohms between the low reference circuit terminal 7 and ground.
• If 2 ohms or greater
1. Ignition OFF, disconnect the X2 harness connector at the K20 Engine Control Module.
2. Test for less than 2 ohms in the low reference circuit end to end.
• If 2 ohms or greater, repair the open or high resistance in the circuit.
• If less than 2 ohms replace the K20 Engine Control Module.
• If less than 2 ohms
4. Ignition OFF, all vehicle systems OFF, test for less than 2 ohms between the ground circuit terminal 4 and ground.
• If 2 ohms or greater
1. Ignition OFF, disconnect the X2 harness connector at the K20 Engine Control Module.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open or high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 2 ohms
5. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 5 and ground.
• If the test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF, remove the test lamp and remove the fuse for the ignition voltage circuit.
2. Test for less than 2 ohms in the ignition voltage circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse.
• If the test lamp does not illuminate and the circuit fuse is open
1. Ignition OFF, remove the test lamp and remove the fuse for the ignition voltage circuit.
2. Test for infinite resistance between the ignition voltage circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for greater than 2 ohms between the ignition voltage circuit terminal 5 and ground.
• If less than 2 ohms, repair the short to ground on the circuit.
• If greater than 2 ohms, test all the components connected to the circuit and repair or replace as necessary.
• If a test lamp illuminates
6. Ignition ON, test for 4.8-5.2 V between the intake air temperature signal 1 circuit terminal 8 and ground.
• If less than 4.8 V
1. Ignition OFF, disconnect the X2 harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K20 Engine Control Module.
• If greater than 5.2 V
Note: If the signal circuit is shorted to a voltage the engine control module or the sensor may be damaged.
1. Ignition OFF, disconnect the X2 harness connector at the K20 Engine Control Module.
2. Ignition ON, test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K20 Engine Control Module.
• If between 4.8-5.2 V
7. Ignition ON, test for 4.8-5.2 V between the intake air temperature signal 2 circuit terminal 1 and ground.
• If less than 4.8 V
1. Ignition OFF, disconnect the X2 harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K20 Engine Control Module.
• If greater than 5.2 V
Note: If the signal circuit is shorted to a voltage the engine control module or the sensor may be damaged.
1. Ignition OFF, disconnect the X2 harness connector at the K20 Engine Control Module.
2. Ignition ON, test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K20 Engine Control Module.
• If between 4.8-5.2 V
8. Ignition OFF, connect the leads of the EN-38522 - variable signal generator as follows:
* Red lead to the signal circuit terminal 1 at the harness connector
* Black lead to ground
* Battery voltage supply lead to B+
9. Set the EN-38522 - variable signal generator to the following specifications.
* Signal switch to 5 V
* Duty Cycle switch to 50 % (Normal)
* Frequency switch to 30 Hz
10. Ignition ON, verify the scan tool IAT Sensor 2 parameter is between 28-32 Hz.
• If not between 28-32 Hz
Replace the K20 Engine Control Module.
• If between 28-32 Hz
11. Ignition OFF, disconnect the harness connector at the B111B Turbocharger Boost/Intake Air Temperature sensor (IAT Sensor 3).
12. Ignition OFF and all systems OFF. It may take up to for 2 minutes for all vehicle systems to power down. Test for less than 2 ohms between the low reference circuit terminal 1 and ground.
• If 2 ohms or greater
1. Ignition OFF, disconnect the X1 harness connector at the K20 Engine Control Module.
2. Test for less than 2 ohms in the low reference circuit end to end.
• If 2 ohms or greater, repair the open or high resistance in the circuit.
• If less than 2 ohms replace the K20 Engine Control Module.
• If less than 2 ohms
13. Ignition ON, test for 4.8-5.2 V between the intake air temperature sensor 3 signal circuit terminal 2 and ground.
• If less than 4.8 V
1. Ignition OFF, disconnect the X1 harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K20 Engine Control Module.
• If greater than 5.2 V
Note: If the signal circuit is shorted to a voltage the engine control module or the sensor may be damaged.
1. Ignition OFF, disconnect the X1 harness connector at the K20 Engine Control Module.
2. Ignition ON, test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K20 Engine Control Module.
• If between 4.8-5.2 V
14. Test or replace the appropriate temperature sensor.
Component Testing
Mass Air Flow/Multifunction Intake Air Sensor (IAT Sensor 1)
1. Ignition OFF, disconnect the harness connector at the B75C Mass Air Flow/Multifunction Intake Air sensor.
Note: A thermometer can be used to test the sensor off the vehicle.
2. Test the IAT sensor 1 by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the Temperature Versus Resistance - Intake Air Temperature Sensor (Delco Sensor) SpecificationsTemperature Versus Resistance - Intake Air Temperature Sensor (Bosch) Specifications table for Bosch Sensors. The resistance values should be in range of the table values.
• If not within the specified range, replace the B75C Mass Air Flow/Multifunction Intake Air sensor (IAT Sensor 1).
Mass Air Flow/Multifunction Intake Air Sensor (IAT Sensor 2)
* Test the IAT Sensor 2 by varying the sensor temperature while monitoring the air temperature with a thermometer. Compare the readings with the scan tool IAT Sensor 2 parameter. The values should be within 5%.
• If not within the specified range, replace the B75C Mass Air Flow/Multifunction Intake Air sensor (IAT Sensor 2).
Turbocharger Boost/Intake Air Temperature sensor (IAT Sensor 3)
1. Ignition OFF, disconnect the harness connector at the B111B Turbocharger Boost/Intake Air Temperature sensor (IAT Sensor 3).
Note: A thermometer can be used to test the sensor off the vehicle.
2. Test the IAT sensor 3 by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the Temperature Versus Resistance - Intake Air Temperature Sensor (Delco Sensor) SpecificationsTemperature Versus Resistance - Intake Air Temperature Sensor (Bosch) Specifications table for Delco sensors. The resistance values should be in range of the table values.
• If not within the specified range, replace the B111B Turbocharger Boost/Intake Air Temperature sensor (IAT Sensor 3).
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Mass Airflow Sensor Replacement Service and Repair for mass air flow/multifunction intake air sensor (IAT Sensor 1 or IAT Sensor 2) replacement.
* Intake Air Pressure and Temperature Sensor Replacement Service and Repair for Turbocharger Boost/Intake Air Temperature Sensor 3 replacement.
* Control Module References Control Module References for engine control module replacement, programming, and setup.