GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P0096: Intake Air Temperature (IAT) Sensor 2 Performance

Diagnostic Fault Information

IAT Sensor 2

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

Signal Performance

IAT Sensor 2 Signal

P0097

P0096

P0098

P0098*

P0096

Low Reference

--

P0096

P0098

*

P0096

*Internal ECM or sensor damage may occur if the circuit is shorted to B+.


IAT Sensor

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

IAT Sensor Signal

P0112

P0113

P0113

P0113*

Low Reference

--

--

--

*

*Internal ECM or sensor damage may occur if the circuit is shorted to B+.

Typical Scan Tool Data

IAT Sensor 2

Circuit

Short to Ground

Open

Short to Voltage

Operating Conditions: Key ON, engine OFF

Parameter Normal Range: Varies between -39 to +120°C (-38 to +248°F)

IAT Sensor 2 Signal

150°C (300°F)

-40°C (-40°F)

-40°C (-40°F)*

Low Reference

--

-40°C (-40°F)

-40°C (-40°F)*

*Internal ECM or sensor damage may occur if the circuit is shorted to B+


IAT Sensor

Circuit

Short to Ground

Open or High Resistance

Short to Voltage

Parameter Normal Range: Varies between -39 to +120°C (-38 to +248°F)

IAT Sensor 1 Signal

140°C (284°F)

-40°C (-40°F)

-40°C (-40°F)*

Low Reference

--

--

--

*Internal ECM or sensor damage may occur if the circuit is shorted to B+

Circuit/System Description

The intake air temperature (IAT) sensor 2 is a variable resistor. The IAT sensor 2 measures the temperature of the air at the engine intake manifold. The engine control module (ECM) supplies 5 volts to the IAT sensor 2 signal circuit, and a ground for the IAT sensor 2 low reference circuit. When the IAT sensor 2 is cold, the sensor resistance is high. When the intake manifold air temperature increases, the sensor resistance decreases. With high sensor resistance, the ECM detects a high voltage on the IAT sensor 2 signal circuit. With lower sensor resistance, the ECM detects a lower voltage on the IAT sensor  2 signal circuit. The ECM monitors the IAT sensor 2 and the IAT sensor signal voltages for a voltage that is not within a calibrated range of each other.

Conditions for Running the DTC

    • DTCs P0097, P0098, P0112, P0113, P0116, P0117, P0118, P0128, P0500, P0502, P0603 are not set.
    • DTC P0116 has run and passed.
    • The engine has been OFF for greater than 8 hours.
    • The IAT sensor is greater than 10°C (50°F).
    • DTC P0096 runs once per key cycle within the enabling conditions.

Conditions for Setting the DTC

    • DTC P0116 must run and pass.
    • At start-up, after an 8 hour engine soak time, the IAT sensor 2 temperature is greater than 20°C (36°F) higher or lower than the IAT sensor.

Action Taken When the DTC Sets

DTC P0096 is a Type B DTC.

Conditions for Clearing the MIL/DTC

DTC P0096 is a Type B DTC.

Diagnostic Aids

    • An IAT sensor that is skewed lower at various ambient temperatures, due to greater resistance than is normal, can widen the spread between the 2 sensors and cause this DTC to set. Measure and record the resistance of the IAT sensor and IAT sensor 2 at various ambient temperatures, and then compare those measurements to the Temperature vs. Resistance Table. Refer to Temperature Versus Resistance.
    • Inspect both IAT sensors terminals, for corrosion or a poor connection.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Important: Perform this verification procedure only if the ignition has been OFF for eight hours or more.

  1. Verify that DTCs P0112, P0113, P0097, or P0098 are not set. If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle.
  2. Ignition ON, observe the scan tool IAT sensor, the IAT sensor 2, and the ECT sensor parameters. The readings should be within 15°C (27°F) of each other, and also the ambient temperature.
  3. Engine running, observe the DTC information with a scan tool. DTC P0096 should not set.
  4. 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 MAF/IAT sensor.
  2. Ignition OFF for 90 seconds, test for less than 5 ohms of resistance between the IAT sensor low reference circuit terminal D and ground.
  3. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  4. Ignition OFF, allow sufficient time for the control module to power down. Disconnect the harness connector at the IAT sensor 2. Test for less than 5 ohms between the IAT sensor 2 low reference circuit terminal B and ground.
  5. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  6. Ignition OFF, disconnect the X2 and X3 harness connectors at the ECM.
  7. Test for less than 5 ohms between the signal circuit terminal E of the IAT sensor and the corresponding terminal X2-62 of the ECM.
  8. If greater than the specified range, repair the open/high resistance in the circuit.
  9. Test for less than 5 ohms of resistance between the signal circuit terminal A of the IAT sensor 2 and the corresponding terminal X2-62 of the ECM.
  10. If greater than the specified range, repair the open/high resistance in the circuit.
  11. If all circuits test normal, test or replace the affected sensor.

Component Testing

  1. Compare the resistance of the IAT sensor 2 sensor to the temperature vs resistance table.
  2. Compare the resistance of the IAT sensor to the temperature vs resistance.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Intake Air Temperature (IAT) Sensor 2 Replacement
    •  Mass Airflow Sensor with Intake Air Temperature Sensor Replacement
    •  Control Module References for ECM replacement, setup, and programming