P0110
DTC P0110 or P0111
DTC Descriptors
DTC P0110
- Intake Air Temperature (IAT) Sensor Circuit
DTC P0111
- Intake Air Temperature (IAT) Sensor Performance
Diagnostic Fault Information
Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Typical Scan Tool Data
Circuit Description
The intake air temperature (IAT) sensor is a variable resistor that measures the temperature of the air entering the engine. The IAT sensor has a signal circuit and a low reference circuit. The engine control module (ECM) supplies 5 volts to the IAT signal circuit and a ground for the IAT low reference circuit.
The following table illustrates the difference between temperature, resistance, and voltage:
Conditions for Running the DTC
P0110
* DTCs P0112, P0113, P1111, P1112 are not set.
* The engine is OFF for more than 8 hours.
* The engine is operating.
* The DTC runs when the above conditions are met.
P0111
* DTCs P0112, P0113, P1111, P1112 are not set.
* The IAT sensor test is ran under 2 different conditions with the following conditions present:
Skew High Test
* The engine airflow is less than 12 g/s.
* The vehicle speed is less than 40 km/h (25 mph).
Skew Low Test
* The engine airflow is less than 12 g/s.
* The vehicle speed is less than 40 km/h (25 mph).
* The ECT sensor is greater than -20°C (-4°F).
* This DTC runs continuously when the above conditions are met.
Conditions for Setting the DTC
P0110
* Cruise Test - The ECM does not detect an intake air temperature (IAT) change of more than 3°C (5°F).
* Startup Test - The ECM does not detect a difference of 3°C (5°F) between the previous ignition cycle IAT and the start-up IAT of the next ignition cycle.
P0111
* Skew High Test - The ECM detects a 20°C (36°F) difference between the start-up IAT and the start-up engine coolant temperature.
* Skew Low Test - The ECM detects a 20°C (36°F) difference between the start-up engine coolant temperature and the start-up IAT.
Action Taken When the DTC Sets
DTC P0110 and P0111 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTC P0110 and P0111 are Type B DTCs.
Diagnostic Aids
* If the vehicle has set overnight, the IAT sensor and the ECT sensor values should display within 3°C (5°F).
* High resistance on either the IAT sensor signal circuit or the IAT sensor low reference circuit may not set a DTC.
Reference Information
Schematic Reference
Engine Controls Schematics Electrical Diagrams
Connector End View Reference
* Engine Control Module (ECM) Connector End Views Engine Control Module (ECM) Connector End Views
* Engine Controls Connector End Views Engine Controls Connector End 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
Diagnostic Trouble Code (DTC) Type Definitions Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
* Scan Tool Data List Scan Tool Data List
* Scan Tool Data Definitions Scan Tool Data Definitions
* Scan Tool Output Controls Scan Tool Output Controls
Circuit/System Verification
1. Verify that the following DTCs are not set: P0112, P0113, P0115, P0117, P0118, P0125, P0128.
• If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
2. Operate the vehicle within the conditions for running the DTC. DTC P0110 or P0111 should not set.
3. If the vehicle passes the Circuit/System Verification Test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector of the IAT sensor.
Important: The DTCs must be cleared or a temperature of 20°C (68°F) will be displayed on the scan tool.
2. Ignition ON, verify that the IAT sensor parameter is at -40°C (-40°F).
• If greater than -40°C (-40°F), test the signal circuit of the IAT sensor for a short to ground. If the circuit/connections test normal, replace the ECM.
3. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit of the IAT sensor and ground.
• If greater than 5 ohms, test the low reference circuit of the IAT sensor for an open/high resistance. If the circuit/connections test normal, replace the ECM.
Important: The DTCs must be cleared or a temperature of 20°C (68°F) will be displayed on the scan tool.
4. Connect a 3-amp fused jumper wire between the signal circuit and the low reference circuit of the IAT sensor and verify the IAT sensor parameter is greater than 128°C (262°F).
• If less than 128°C (262°F), test the signal circuit of the IAT sensor for an open/high resistance. If the circuit/connections test normal, replace the ECM.
5. If all circuits/connections test normal, test or replace the IAT sensor.
Component Testing
1. Ignition OFF, disconnect the harness connector of the IAT sensor.
Important: 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 vs Resistance Temperature vs Resistance table and verify that the resistance is within 5 percent of the specification.
• If the resistance Vs. temperature is not within 5 percent, replace the IAT sensor.
Repair Instructions
Important: Always perform the Diagnostic Repair Verification Diagnostic Repair Verification after completing the diagnostic procedure.
* Intake Air Temperature (IAT) Sensor Replacement Service and Repair
* Control Module References Control Module References for engine control module replacement, setup, and programming