P0111

DTC 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 prior to using this diagnostic procedure. Testing and Inspection

TYPICAL SCAN TOOL DATA

IAT Sensor:

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 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 engine coolant temperature (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 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 ECT.
- Skew Low Test-The ECM detects a 20°C (36°F) difference between the start-up ECT 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.

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 Descriptions
2. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. 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 List.

CIRCUIT/SYSTEM TESTING
1. Ignition OFF, disconnect the harness connector of the IAT sensor.
2. Ignition ON, verify that the IAT sensor parameter is at -40°C (-40°F).

IMPORTANT: The DTCs must be cleared or a temperature of 20°C (68°F) will be displayed on the scan tool.

- 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.
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).

IMPORTANT: The DTCs must be cleared or a temperature of 20°C (68°F) will be displayed on the scan tool.

- 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.
2. Test the IAT sensor by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the Temperature vs Resistance table and verify that the resistance is within 5 percent of the specification.

IMPORTANT: A thermometer can be used to test the sensor off the vehicle.

- If the resistance vs. temperature is not within 5 percent, replace the IAT sensor.

REPAIR INSTRUCTIONS
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests