P0111
P0111 - Intake Air Temperature Sensor 1 Performance
For wiring diagrams, refer to.
Theory of Operation
The PCM compares the intake air temperature sensor, ambient air temperature sensor, and engine coolant temperature sensor values. If one value is not within a specific range of the other two, a second comparison is made after a short drive cycle. If the intake air temperature sensor value is still not within the range, it is determined to be irrational.
• When Monitored: With engine run time greater than 1 minute, ambient temperature more than -64 °C (-83 °F), following an engine off period of more than 480 minutes.
• Set Condition: The PCM compares the intake air temperature sensor, ambient air temperature sensor, and engine coolant temperature sensor values. If the ambient air temperature sensor and engine coolant temperature sensor are within a specific range of each other, but the intake air temperature sensor is not, the intake air temperature sensor value is declared irrational. Two trip fault. Three good trips to turn off the MIL.
• Always perform the pre-diagnostic troubleshooting procedure before proceeding. Refer to => Non-DTC Based Diagnostics. Pre-Diagnostic Troubleshooting Procedure
Test Step 1 - DTC is Active
• Diagnose and repair any CAN C communication or message DTCs in any module before continuing with this procedure.
• Turn the ignition ON.
• With the scan tool, select view DTCs and review the DTC environmental data for this DTC.
Is the good trip counter greater than 0?
Yes
• Go to Test Step 2 => [ Test
Step 2 - Ambient Air Temperature ]
No
• Go to Test Step 3 => [ Test
Step 3 - IAT Signal Circuit Shorted to Voltage ]
Test Step 2 - Ambient Air Temperature
• Turn the ignition OFF.
• Allow the vehicle to sit with the ignition off in an environment where the temperature is consistent and more than - 7 °C (19.4 °F) until the actual engine temperature is equal to actual ambient temperature.
• Turn the ignition ON.
• With a scan tool, compare the engine temperature sensor values of the ambient temperature sensor, engine coolant temperature sensor, intake air temperature sensor, and, if equipped, the engine oil temperature sensor.
Is the intake air temperature sensor value within 10 °C (18 °F) of the other sensor values?
Yes
• Refer to the checking for an intermittent DTC diagnostic procedure. Refer => Non-DTC Based Diagnostics.
No
• Go to Test Step 3 => [ Test
Step 3 - IAT Signal Circuit Shorted to Voltage ]
Test Step 3 - IAT Signal Circuit Shorted to Voltage
• Turn the ignition OFF.
• Disconnect the intake air temperature sensor connector.
• Disconnect the PCM connector.
• Turn the ignition ON.
• Measure the voltage of the IAT signal circuit in the intake air temperature sensor harness connector.
Is there any voltage present?
Yes
• Repair the IAT signal circuit for a short to voltage.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
No
• Go to Test Step 4 => [ Test
Step 4 - IAT Signal Circuit Shorted to Ground ]
Test Step 4 - IAT Signal Circuit Shorted to Ground
• Turn the ignition OFF.
• Measure the resistance between ground and the IAT signal circuit in the intake air temperature sensor harness connector.
Is the resistance more than 100 ohms?
Yes
• Go to Test Step 5 => [ Test
Step 5 - IAT Signal Circuit Shorted to Sensor Ground Circuit ]
No
• Repair the IAT signal circuit for a short to ground.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
Test Step 5 - IAT Signal Circuit Shorted to Sensor Ground Circuit
• Measure the resistance between the IAT signal circuit and the sensor ground circuit in the intake air temperature sensor harness connector.
Is the resistance more than 100 ohms?
Yes
• Go to Test Step 6 => [ Test
Step 6 - IAT Signal Circuit Open or High Resistance ]
No
• Repair the IAT signal circuit for a short to the sensor ground circuit.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
Test Step 6 - IAT Signal Circuit Open or High Resistance
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.
• Measure the resistance of the IAT signal circuit between the intake air temperature sensor harness connector and the appropriate terminal of special tool #8815.
Is the resistance less than 5.0 ohms?
Yes
• Go to Test Step 7 => [ Test
Step 7 - Sensor Ground Circuit Open or High Resistance ]
No
• Repair the IAT signal circuit for an open or high resistance.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
Test Step 7 - Sensor Ground Circuit Open or High Resistance
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.
• Measure the resistance of the sensor ground circuit between the intake air temperature sensor harness connector and the appropriate terminal of special tool #8815.
Is the resistance less than 5.0 ohms?
Yes
• Go to Test Step 8 => [ Test
Step 8 - Intake Air Temperature Sensor Signal Voltage ]
No
• Repair the sensor ground for an open circuit or high resistance.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
Test Step 8 - Intake Air Temperature Sensor Signal Voltage
• Turn the ignition OFF.
• Connect the PCM connector.
• Turn the ignition ON.
• With the scan tool, read the intake air temperature sensor signal voltage.
• The intake air temperature sensor signal voltage should be approximately 5.0 volts (plus or minus 0.2 volts) with the intake air temperature sensor connector disconnected.
• Turn the ignition OFF.
• Connect a jumper wire between the sensor ground circuit and the IAT signal circuit in the intake air temperature sensor harness connector.
• Turn the ignition ON.
• With the scan tool, read the intake air temperature sensor signal voltage.
• The intake air temperature sensor signal voltage should be approximately 0.0 volts (plus or minus 0.2 volts) with the jumper wire in place.
Is the voltage within the ranges specified?
Yes
• Go to Test Step 9 => [ Test
Step 9 - Intake Air Temperature Sensor ]
No
• Go to Test Step 10 => [ Test
Step 10 - PCM ]
Test Step 9 - Intake Air Temperature Sensor
• Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the intake air temperature sensor and the powertrain control module.
• Look for any chafed, pierced, pinched, or partially broken wires.
• Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.
• Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
• Look for the data to change or for the DTC to reset during the wiggle test.
• Refer to any technical service bulletins that may apply.
Were any problems found?
Yes
• Repair as necessary.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
No
• Replace the intake air temperature sensor.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
Test Step 10 - PCM
• Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the intake air temperature sensor and the powertrain control module.
• Look for any chafed, pierced, pinched, or partially broken wires.
• Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.
• Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
• Look for the data to change or for the DTC to reset during the wiggle test.
• Refer to any technical service bulletins that may apply.
Were any problems found?
Yes
• Repair as necessary.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
No
• Replace the PCM.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test