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 Descriptors
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 intake air temperature (IAT) sensor 1 is a variable resistor that measures the temperature of the air in the sensor bore. The engine control module (ECM) supplies 5 V to the IAT sensor 1 signal circuit and a ground for the IAT sensor 1 low reference circuit. The signal varies with inlet air temperature and is displayed by the scan tool as °C (°F).
The IAT sensor 2 produces a frequency signal based on the inlet air temperature very close to the humidity sensor within the sensor bore. The signal varies with inlet air temperature and is displayed by the scan tool as °C (°F) and Hertz (Hz). The ECM applies 5 V to the circuit. The signal circuit is shared by the IAT sensor 2 and the humidity sensor. Ignition voltage and ground circuits are also supplied to the multifunction intake air sensor's internal circuits for these sensors:
* IAT sensor 2
* Humidity sensor
* MAF sensor
The multifunction intake air sensor houses the following:
* IAT sensor 1
* IAT sensor 2
* Humidity sensor
* MAF sensor
* BARO pressure sensor
Conditions for Running the DTCs
P0096 and P0111
* DTCs P0097, P0098, P0112, P0113, P0116, P0117, P0118, 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 25°C (45°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 25°C (45°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
* An IAT sensor 1 that is skewed, due to more resistance than is normal, can widen the spread between the 2 sensors and cause this 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 Electrical Specifications.
* A slight to moderate resistance in the IAT sensor 1 signal circuit or low reference circuit will increase the range between these two 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 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 Connector Views
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
* J 38522 Variable Speed Generator
* For equivalent regional tools, refer to Special Tools (Diagnostic Tools) Tools and Equipment.
Circuit/System Verification
Note: 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
* Start-Up ECT
2. Engine running, observe the scan tool IAT Sensor 1 and IAT Sensor 2 Sensor parameters. Depending on the current ambient temperature and the vehicle operating conditions, the readings should be between:
* -38 and +149°C (-36 and +300°F) for IAT sensor 1
* -38 and +149°C (-36 and +300°F) for IAT sensor 2
3. 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 systems OFF. It may take up to for 2 minutes for all vehicle systems to power down. Test for less than 5 ohm between the low reference circuit terminal 3 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 ECM.
3. Ignition OFF, all vehicle systems OFF, test for less than 5 ohm between the ground circuit terminal 7 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
4. Ignition ON, 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 for a short to ground. If the circuit tests normal, replace the K20 ECM.
Note: If the fuse in the jumper wire opens, the signal circuit is shorted to a voltage the ECM or the sensor may be damaged.
5. Install a 3 A fused jumper wire between the signal circuit terminal 1 and ground. Verify the scan tool IAT Sensor 1 parameter is warmer than 149°C (300°F).
• If colder 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 ECM.
6. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 5 and ground.
• If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
• If the circuit tests normal and the fuse is open, test all the components connected to the circuit and repair or replace as necessary.
7. Ignition ON, test for 4.8-5.2 V between the IAT sensor 2 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 ECM.
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 ECM.
8. Ignition OFF, connect the red lead of the J 38522 to the signal circuit terminal 8 at the harness connector. Connect the battery voltage supply to B+, and the black lead to ground.
9. Set the J 38522 to the following specifications.
* Signal switch to 5 V
* Duty Cycle switch to 50 % (Normal)
* Frequency switch to 30 Hz
10. Ignition ON, observe the scan tool IAT Sensor 2 parameter. The scan tool parameter should be between 28-32 Hz.
• If the parameter is not within the specified range, replace the K20 ECM.
11. If all circuits test normal, test or replace the B75C multifunction intake air sensor.
Component Testing
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 Electrical Specifications 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.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Mass Airflow Sensor with Intake Air Temperature Sensor Replacement Service and Repair for multifunction intake air sensor replacement.
* Control Module References Control Module References for engine control module replacement, programming, and setup.