Diagnostic Instructions

DTC Descriptor

DTC P0111 00: Intake Air Temperature (IAT) Sensor Performance

DTC P0112 00: Intake Air Temperature (IAT) Sensor Circuit Low Voltage

DTC P0113 00: Intake Air Temperature (IAT) Sensor Circuit High Voltage

Diagnostic Fault Information

Circuit	Short to Ground	High Resistance	Open	Short to voltage	Signal Performance
IAT Sensor Signal	P0112 00, P0114 00	P0113 00, P0114 00	P0113 00, P0114 00	P0113 00, P0114 00	P0111 00, P0114 00
Low Reference	--	P0113 00, P0114 00	P0113 00, P0114 00	P0113 00, P0114 00	P0111 00, P0114 00

Typical Scan Tool Data

IAT Sensor

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: The ignition is ON, or the engine is running Parameter Normal Range: Varies with ambient temperature
IAT Sensor Signal	129°C (264°F)	-40°C (-40°F)	-40°C (-40°F)
Low Reference	--	-40°C (-40°F)	-40°C (-40°F)

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

P0112 00 and P0113 00

Conditions for Setting the DTC

P0111 00

The ECM detects that the IAT deviates less than 1.5°C (35°F) since engine start.

P0112 00

The ECM detects that the IAT sensor voltage is less than 0.15 V for greater than 0.1 s.

P0113 00

The ECM detects that the IAT sensor voltage is more than 4.85 V for greater than 0.1 s.

Action Taken When the DTC Sets

DTCs P0111 00, P0112 00 and P0113 00 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P0111 00, P0112 00 and P0113 00 are Type B DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Air Intake System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References

Circuit/System Verification

1. Engine running, observe the scan tool Intake Air Temperature parameter. The reading should be between -38 to +149°C (-38 to +300°F) depending on the current ambient temperature and the vehicle operating conditions.
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 data.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the B66 Intake Air Temperature (IAT) Sensor.
2. Ignition OFF for 90 s, test for less than 5 Ω between the low reference circuit terminal B 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 Engine Control Module (ECM).

3. Ignition ON, verify the scan tool IAT is colder than -39°C (-38°F).

⇒	If greater than the specified range, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

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

5. If all circuits test normal, test or replace the B66 Intake Air Temperature (IAT) Sensor.

Component Testing

Static Test

Measure and record the resistance of the B66 Intake Air Temperature (IAT) Sensor at various ambient temperatures, then compare those measurements to the Temperature Versus Resistance table.

Repair Instructions

Perform the Diagnostic Repair Verification