P0111
DTC 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 P0111 00
- 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. 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
P0111 00
* DTCs P0501 00, P0116 00, P0117 00, P0118 00, P0119 00, P0112 00, P0113 00, P0114 00, P0107 00 or P0108 00 are not set.
* The engine run time is greater than 10 min.
Conditions for Setting the DTC
P0111 00
The ECM detects that the IAT deviates less than 1.5°C (35°F) since engine start.
Action Taken When the DTC Sets
DTCs P0111 00 is a Type B DTCs.
Conditions for Clearing the DTC
DTCs P0111 00 is a Type B DTCs.
Reference Information
Schematic Reference
Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
Air Intake System Description (Air Intake System)
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 (Programming and Relearning)for scan tool information
Circuit/System Verification
1. If the ignition has been OFF for 8 h or greater, the B75B Mass Air Flow/Intake Air Temperature Sensor (IAT 1), the B65 Intake Manifold Pressure and Air Temperature Sensor (IAT 2) and the B34A Engine Coolant Temperature Sensor 1 should be within 9°C (16°F) of each other. Ignition ON, observe the scan tool IAT Sensor, IAT Sensor 2 and the ECT Sensor parameters. Compare those sensor parameters to each other to determine if the condition is current.
2. Engine running, observe the scan tool IAT Sensor parameter. The reading should be between -39 to +120°C (-38 to +248°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 ground circuit terminal 2 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, test for 4.8-5.2 V between the B75B Mass Air Flow/Intake Air Temperature Sensor (IAT 1) low reference circuit terminal 3 and ground.
• If less 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.
4. 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 1 for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.
5. Install a 3 A fused jumper wire between the B75B Mass Air Flow/Intake Air Temperature Sensor signal circuit terminal 3 and the low reference terminal 1. Verify the scan tool IAT Sensor parameter is warmer than 142°C (288°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.
6. If all circuits/connections test normal, replace the B75B Mass Air Flow/Intake Air Temperature Sensor.
Component Testing
Static Test
Measure and record the resistance of the B75B Mass Air Flow/Intake Air Temperature Sensor (IAT 1) at various ambient temperatures, then compare those measurements to the Temperature Versus Resistance (IAT) (Temperature Versus Resistance (IAT))Temperature Versus Resistance (ECT) (Temperature Versus Resistance (ECT)) table.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Control Module References (Programming and Relearning)for ECM replacement, setup, and programming