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 Descriptors
DTC P0097: Intake Air Temperature (IAT) Sensor 2 Circuit Low VoltageDTC P0098: Intake Air Temperature (IAT) Sensor 2 Circuit High Voltage
Diagnostic Fault Information
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
|---|---|---|---|---|---|
IAT Sensor Signal 2 | P0097 | P0096 | P0098 | P0098 | P0096 |
Low Reference | -- | P0096 | P0098 | -- | P0096 |
Typical Scan Tool Data
Circuit | Normal Range | Short to Ground | Open or High Resistance | Short to Voltage |
|---|---|---|---|---|
IAT Sensor 2 Signal | Varies¹ | 150°C (300°F) | -40°C (-40°F) | -40°C (-40°F)* |
IAT Sensor 2 Low Reference | -- | -- | -40°C (-40°F) | -40°C (-40°F)* |
¹Varies -39 to +120°C (-38 to +248°F) *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 has a signal circuit and a low reference circuit. The IAT sensor measures the temperature of the air at the engines intake manifold. The engine control module (ECM) supplies 5V to the IAT 2 signal circuit, and a ground for the IAT 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 2 signal circuit. With lower sensor resistance, the ECM detects a lower voltage on the IAT 2 signal circuit. The ECM continuously monitors the IAT signal voltage for an excessively high or low voltage, or a voltage signal that is not in correlation with the mass air flow (MAF)/IAT sensor.
Conditions for Running
| • | The engine run has been in operation for greater than 10 seconds. |
| • | The engine coolant temperature (ECT) is greater than -40°C (-40°F). |
| • | The vehicle speed is greater than 1 km/h (1 mph). |
| • | The MAF is less than 512 g/s. |
| • | 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 5 seconds. This is equal to or less than 0.24V on the IAT sensor 2 signal circuit as measured by the ECM for P0097.
P0098
The IAT sensor 2 is colder than -39°C (-38°F) for greater than 5 seconds. This is equal to or greater than 4.86V on the IAT signal circuit as measured by the ECM for P0098.
Action Taken When the DTC Sets
DTCs P0097 and P0098 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs P0097 and P0098 are Type B DTCs.
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
DTC Type Definitions
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Note: Perform this verification procedure only if the ignition has been OFF for 8 hours or more.
- Ignition ON, observe the scan tool IAT Sensor, IAT Sensor 2, and ECT Sensor parameters. The readings should be within 15°C (27°F) of each other, and also the ambient temperature.
- 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
- Ignition OFF, disconnect the harness connector at the IAT sensor 2.
- Ignition OFF for 90 seconds, test for less than 5Ω between the low reference circuit terminal B and ground.
- Ignition ON, verify the scan tool IAT sensor 2 parameter is less than -39°C (-38°F).
- Install a 3A fused jumper wire between the signal circuit and the low reference circuit. Verify the scan tool IAT sensor 2 parameter is greater than 130°C (266°F).
- If all circuits test normal, test or replace IAT sensor 2.
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
| ⇒ | If greater than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM. |
| ⇒ | If less than the specified range, test the signal circuit terminal A for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM. |
Component Testing
Compare the IAT sensor 2 resistance to the values listed in the Temperature vs. Resistance table. Refer to Temperature Versus Resistance.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for ECM replacement, setup, and programming |
