P0097

DTC P0097 or P0098

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 provide an overview of each diagnostic category.

DTC Descriptors

DTC P0097
- Intake Air Temperature (IAT) Sensor 2 Circuit Low Voltage

DTC P0098
- Intake Air Temperature (IAT) Sensor 2 Circuit High Voltage

Diagnostic Fault Information






Typical Scan Tool Data






Circuit/System Description

The intake air temperature (IAT) sensor 2 is a variable resistor. The IAT sensor 2 has a signal circuit and a low reference circuit. The IAT sensor 2 measures the temperature of the air at the engines 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 continuously monitors the IAT sensor 2 signal voltage for an excessively high or low voltage, or a voltage signal that is not in correlation with the engine coolant temperature (ECT) sensor 1.

Conditions for Running the DTC

DTC P0097 and P0098 run continuously within the enabling conditions.

Conditions for Setting the DTC

P0097

The IAT sensor 2 is greater than 148°C (298°F) for greater than 1 second. This is equal to or less than 0.10 volt on the IAT sensor 2 signal circuit as measured by the ECM.

P0098

The IAT sensor 2 is less than -39°C (-38°F) for greater than 1 second. This is equal to or greater than 4.8 volts on the IAT sensor 2 signal circuit as measured by the ECM.

Action Taken When the DTC Sets

DTCs P0097 and P0098 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P0097 and P0098 are Type B DTCs.

Circuit/System Verification

* Ignition ON, observe the scan tool IAT Sensor, IAT Sensor 2, and ECT Sensor parameters. The reading should be within 15°C (27°F) of each other and also the ambient temperature.
* Engine running, observe the DTC information with a scan tool. DTCs P0097 or P0098 should not set.
* 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 Records data.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the IAT sensor 2.
2. Ignition OFF, for 90 seconds, test for less than 5 ohms of resistance 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 ECM.

3. Ignition ON, verify the scan tool IAT Sensor 2 parameter is less 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 ECM.

4. Install a 3A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal B. Verify the scan tool IAT Sensor 2 parameter is greater than 130°C (266°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 ECM.

5. If all circuits test normal, test or replace the IAT sensor 2.

Component Testing

Static Test
1. Ignition OFF, disconnect the harness connector at the IAT sensor 2.
2. Measure the resistance between the signal terminal A and the low reference circuit terminal B.
3. Compare the value to the Temperature Vs Resistance table. Verify the resistance is within 9 percent of the specification. Refer to Temperature Versus Resistance (Exhaust Gas Temperature Sensor) Temperature Versus Resistance (Fuel Temperature Sensor) Temperature Versus Resistance (IAT Sensor 1) Temperature Versus Resistance (ECT Sensors) Temperature Versus Resistance (IAT Sensor 2).

• If not within the specified range, replace the IAT sensor 2.

Dynamic Test

Important: A thermometer can be used to test the sensor off the vehicle in heated water.

1. Test the IAT sensor 2 by varying the sensor temperature while monitoring the sensor resistance.
2. Compare the readings with the Temperature Vs Resistance table and verify that the resistance is within 9 percent of the specification.

• If not within the specified range, replace the IAT sensor 2.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

* Intake Air Temperature (IAT) Sensor 2 Replacement
* Control Module References for ECM replacement, setup, and programming Programming and Relearning Verification Tests