P0111
DTC P0111 (LUJ)
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 P0111
- Intake Air Temperature (IAT) Sensor Performance
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The intake air temperature (IAT) sensor is a variable resistor and is integrated in the mass air flow meter. The IAT sensor has a signal circuit and a low reference circuit. The IAT sensor measures the temperature of the air entering the engine. The engine control module (ECM) supplies 5 V to the IAT signal circuit, and a ground for the IAT low reference circuit.
Conditions for Running the DTC
* DTCs P0116, P0117, P0118, P0119, P0112, P0113 or P0114 are not set.
* The time between current ignition cycle and the last time the engine was running is greater than 8 h.
Conditions for Setting the DTC
The ECM detects an IAT sensor that has stuck in range by comparing to engine coolant temperature at startup.
Action Taken When the DTC Sets
DTC P0111 is Type B DTC.
Conditions for Clearing the DTC
DTC P0111 is Type B DTC.
Reference Information
Schematic Reference
Engine Controls Schematics (LUJ) [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Sunshade - Left (D6I)
Description and Operation
Air Intake System Description Air Intake System Description
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
Circuit/System Verification
Note: Perform Step 1 of this verification procedure only if the engine has been OFF for 8 h or more.
1. Ignition ON, observe the scan tool parameters list below. The readings should be within 40°C (72°F) of each sensor.
* IAT Sensor
* Engine coolant temperature (ECT) Sensor
* IAT Sensor 2
2. Engine running, observe the scan tool IAT sensor parameter. The reading should be between -38 to +149°C (-36 to +300°F), depending on the current ambient temperature and the vehicle operating conditions.
3. Operate the vehicle within the conditions for running the DTC to verify 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 B75B Mass Air Flow/Intake Air Temperature Sensor.
2. Ignition OFF for 90 s, test for less than 5 ohm 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.
3. Ignition ON, verify the scan tool IAT Sensor parameter is colder than -39°C (-38°F).
• If warmer than the specified range, test the signal circuit terminal 3 for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.
4. Install a 3 A fused jumper wire between the B75B Mass Air Flow/Intake Air Temperature Sensor signal circuit terminal 3 and ground. Verify the scan tool IAT Sensor parameter is warmer than 149°C (300°F).
• If less 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.
5. If all circuits/connections test normal, replace the B75B Mass Air Flow/Intake Air Temperature Sensor.
Component Testing
Dynamic Test
1. Ignition OFF, disconnect the harness connector at the B75B Mass Air Flow/Intake Air Temperature Sensor.
Note: A thermometer can be used to test the sensor off the vehicle
2. Test the IAT sensor by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the Temperature Versus Resistance Temperature Versus Resistance
• If not within the specified range, replace the B75B Mass Air Flow/Intake Air Temperature Sensor.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Mass Airflow Sensor Replacement (1.4L LUH and LUJ) Service and Repair
* Control Module References Control Module References for ECM replacement, programming and setup