Volt

DTC P0111

The intake air temperature (IAT) sensor is integrated with the mass air flow (MAF) sensor. It 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 ECM determines the absolute difference between IAT start-up temperature and the ECT start-up temperature is greater than 40°C (72°F).

DTC P0111 is a Type B DTC.

DTC P0111 is a Type B DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Hybrid Modes of Operation Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Note: Perform Step 1 of this verification procedure only if the vehicle has been OFF for 8 hours or more.

1. Vehicle in Service Mode, observe the following scan tool parameters. The readings should be within 40°C (72°F) of each other.

•	Start-Up IAT

•	Start-Up ECT

2. Engine running, observe the scan tool IAT sensor parameter. The reading should be between -38 and +149°C (-36 and +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 that the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.

1. Vehicle OFF, disconnect the harness connector at the B75B mass air flow/inlet air temperature sensor.
2. Vehicle OFF, all systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 Ω 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. If the circuit tests normal, replace the K20 ECM.

3. Vehicle in Service Mode, verify the scan tool IAT Sensor parameter is colder than -39°C (-38°F).

⇒	If warmer than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.

Note: If the fuse in the jumper wire opens, the signal circuit is shorted to a voltage and the ECM or the sensor may be damaged.

4. Install a 3 A fused jumper wire between the signal circuit terminal 3 and ground. Verify the scan tool IAT Sensor parameter is warmer than 149°C (300°F).

⇒	If colder 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 ECM.

5. If all circuits test normal, test or replace the B75B mass air flow/intake air temperature sensor.

1. Vehicle OFF, disconnect the harness connector at the B75B mass air flow/inlet 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 . The resistance values should be in range of the table values.

⇒	If not within the specified range, replace the B75B mass air flow/inlet air temperature sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.