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, P0111, P0112, P0113, P0117, P0118, P112C, P112D, or P1682 are not set.
* The ignition has been OFF at least 8 hours.
* Ignition 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 25°C (45°F).
AND
* The ECM determines the absolute difference between IAT sensor 2 start-up temperature and the IAT sensor 3 start-up temperature is greater than 25°C (45°F).
AND
* The ECM determines the absolute difference between IAT sensor 1 start-up temperature and the IAT sensor 3 start-up temperature is less than or equal to 25°C (45°F).
* This DTC runs once per ignition cycle when the enabling conditions are met.
Note: P0111 Can fail under the following 3 sets of conditions.
P0111 - Condition 1
* The ECM determines the absolute difference between IAT sensor 1 start-up temperature and the IAT sensor 2 start-up temperature is greater than 25°C (45°F).
AND
* The ECM determines the absolute difference between IAT sensor 1 start-up temperature and the IAT sensor 3 start-up temperature is greater than 25°C (45°F).
AND
* The ECM determines the absolute difference between IAT sensor 2 start-up temperature and the IAT sensor 3 start-up temperature is less than or equal to 25°C (45°F).
P0111 - Condition 2
* The ECM determines the IAT sensor 2 start-up temperature is between the IAT sensor 1 and IAT sensor 3 start-up temperatures.
AND
* The ECM determines the absolute difference between IAT sensor 1 start-up temperature and the IAT sensor 3 start-up temperature is greater than 25°C (45°F).
AND
* The ECM determines the absolute difference between IAT sensor 2 and the IAT sensor 1 start-up temperatures is greater than absolute difference between IAT sensor 2 and the IAT sensor 3 start-up temperatures.
P0111 - Condition 3
* The ECM determines the IAT sensor 3 start-up temperature is between the IAT sensor 1 and IAT sensor 2 start-up temperatures.
AND
* The ECM determines the absolute difference between IAT sensor 1 start-up temperature and the IAT sensor 2 start-up temperature is greater than 25°C (45°F).
AND
* The ECM determines the absolute difference between IAT sensor 3 and the IAT sensor 1 start-up temperatures is greater than absolute difference between IAT sensor 3 and the IAT sensor 2 start-up temperatures.
DTC P0111 runs once an ignition cycle when the one of the above 3 enabling sets of 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
* With the ignition ON, when the engine is cold and not running, properly functioning IAT sensor 1 and 2 will gradually increase the scan tool IAT Sensor 1 and 2 parameters. This is due to the heat that is generated by the mass air flow/multifunction intake air sensor heating elements.
* An IAT sensor 1 that is skewed, due to more 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 at various ambient temperatures, and then compare those measurements to the Temperature vs. Resistance Table. Refer to Temperature Versus Resistance - Intake Air Temperature Sensor (Bosch Sensor) Temperature Versus Resistance - Intake Air Temperature Sensor (Bosch Sensor)Temperature Versus Resistance - Intake Air Temperature Sensor (Delco Sensor) Temperature Versus Resistance - Intake Air Temperature Sensor (Delco Sensor) table for Bosch Sensors.
* A slight to moderate resistance in the IAT sensor 1 signal circuit or low reference circuit will increase the range between the sensors. This condition results in a greater voltage on the IAT sensor 1 signal circuit, which is interpreted by the ECM as a colder IAT sensor 1.
* Inspect the multifunction intake air sensor terminals for corrosion.
* The scan tool IAT Sensor 2 parameter displays the values: 10 Hz; 20°C (68°F) when there is a fault on the signal circuit.
* 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; 20°C (68°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 Fuel Pump and Level Sensor Assembly
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 the sensor heating elements, perform Step 1 of this verification procedure only if the ignition has been OFF for 8 hours or more.
1. Ignition ON, observe the following scan tool parameters. The readings should be within 25°C (45°F) of each other.
* Start-Up IAT Sensor 1
* IAT Sensor 2
* IAT Sensor 3
2. Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0651 is not set.
• If the DTC is set, refer to DTC P0641, P0651, P0697, or P06A3 (ECM) Powertrain Management (ECM) for further diagnosis.
3. Engine idling, observe the scan tool IAT Sensor 1, IAT Sensor 2, and IAT Sensor 3 parameters. Depending on the current ambient temperature and the vehicle operating conditions, the readings should be between -39 and +149°C (-38 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.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the B75C Multifunction Intake Air Sensor.
2. Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes, test for less than 5 ohms between the low reference circuit terminal 7 and ground.
• 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.
3. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 2 and ground.
• If less than the specified range, test the circuit for an open/high resistance, or short to ground on the 5 V reference circuit. If the circuit tests normal, replace the K20 Engine Control Module.
• If greater than the specified range, test for a short to voltage on the 5 V reference circuit. If the circuit tests normal, replace the K20 Engine Control Module.
4. Verify the scan tool IAT Sensor 1 parameter is colder than -39°C (-38°F).
• If warmer than the specified range, test the signal circuit terminal 8 for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.
5. Test for 4.8-5.2 V between the IAT sensor 1 signal circuit terminal 8 and ground.
• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
Note: If the signal circuit is shorted to a voltage the ECM or the sensor may be damaged.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.
6. Test for 4.8-5.2 V between the IAT sensor 2 signal circuit terminal 1 and ground.
• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
Note: If the signal circuit is shorted to a voltage the ECM or the sensor may be damaged.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.
7. 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+
8. 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
9. Ignition ON. Observe the scan tool IAT Sensor 2 frequency (Hz) parameter. The scan tool parameter should display between 28-32 Hz.
• If the parameter is not within the specified range, replace the K20 Engine Control Module.
10. Ignition OFF, disconnect the harness connector at the B111 Turbocharger Boost/Intake Air Temperature sensor.
11. Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes, test for less than 5 ohms between the low reference circuit terminal 1 and ground.
• 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.
12. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 3 and ground.
• If less than the specified range, test the circuit for an open/high resistance, or short to ground on the 5 V reference circuit. If the circuit tests normal, replace the K20 Engine Control Module.
• If greater than the specified range, test for a short to voltage on the 5 V reference circuit. If the circuit tests normal, replace the K20 Engine Control Module.
13. Verify the scan tool IAT Sensor 3 parameter is colder than -39°C (-38°F).
• If warmer 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.
14. Test for 4.8-5.2 V between the IAT sensor 3 signal circuit terminal 2 and ground.
• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
Note: If the signal circuit is shorted to a voltage the ECM or the sensor may be damaged.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.
15. If all circuits test normal, test or replace the B75C Multifunction Intake Air Sensor.
Component Testing
Mass Air Flow/Multifunction Intake Air sensor
1. Ignition OFF, disconnect the harness connector at the B75C 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 (Bosch Sensor) Temperature Versus Resistance - Intake Air Temperature Sensor (Bosch Sensor)Temperature Versus Resistance - Intake Air Temperature Sensor (Delco Sensor) Temperature Versus Resistance - Intake Air Temperature Sensor (Delco Sensor) Bosch sensor table. The resistance values should be in range of the table values.
• If not within the specified range, replace the B75C Multifunction Intake Air Sensor.
Turbocharger Boost/Intake Air Temperature sensor
1. Ignition OFF, disconnect the harness connector at the B111 Turbocharger Boost/Intake Air Temperature sensor.
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 (ECT, IAT) Temperature Versus Resistance (ECT, IAT) IAT sensor table. The resistance values should be in range of the table values.
• If not within the specified range, replace the B111 Turbocharger Boost/Intake Air Temperature sensor.
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 replacement.
* Intake Air Pressure and Temperature Sensor Replacement Service and Repair for Turbocharger Boost/Intake Air Temperature sensor replacement.
* Control Module References Control Module References for Engine Control Module replacement, programming, and setup.