Circuit Description
This diagnostic monitors the signal of the intake air temperature (IAT) sensor. The IAT sensor is a variable resistor that measures the temperature of the intake air. The powertrain control module (PCM) supplies 5 volts to the IAT signal circuit and supplies a ground to the low reference circuit.
Two ECT sensors and intake air temperature (IAT) sensors are used by the PCM. When the engine is stopped and enough time has passed, the temperature of the engine will equal the ambient temperature. If the temperature of IAT sensor 2 is outside of the expected range after comparing the temperature readings of each sensor, this DTC sets.
The following table illustrates the difference between temperature, resistance, and voltage:
IAT | IAT Sensor Resistance | IAT Sensor Signal Voltage |
|---|---|---|
Cold | High | High |
Warm | Low | Low |
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0096 Intake Air Temperature (IAT) Sensor 2 Performance
Conditions for Running the DTC
| • | DTC P0112, P0113, P0116, P0117, P0118, P0125, P01126, P2183, P2184, P2185 and P2610 are not set. |
| • | The engine has been OFF for more than 6 consecutive hours. |
| • | The engine is started and idled for at least 10 seconds. |
| • | DTC P0096 runs once per drive cycle when the above conditions are met. |
Conditions for Setting the DTC
The DTC sets when any of the following conditions are not met at start up, after the engine has been OFF for at least 6 hour.
| • | The difference in temperature between the intake air temperature (IAT) sensor 2 and the engine coolant temperature (ECT) sensor 1 is more than 38°C (100°F). |
| • | The difference in temperature between the IAT sensor 2 and the ECT sensor 2 is more than 23°C (73°F). |
| • | The difference in temperature between the ECT sensor 1 and the ECT sensor 2 is more than 24°C (75°F). |
Action Taken When the DTC Sets
| • | The PCM illuminates the malfunction indicator lamp (MIL) after 2 consecutive ignition cycles in which the diagnostic runs with the fault active. |
| • | The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Freeze Frame/Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The PCM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A last test failed, or current DTC, clears when the diagnostic runs and does not fail. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Use a scan tool in order to clear the MIL and the DTC. |
Diagnostic Aids
| • | Use the Temperature vs Resistance table in order to test the IAT sensor at various temperature levels in order to evaluate the possibility of a skewed sensor. A skewed sensor could result in a driveability concern. If the engine has sat overnight, the engine coolant temperature and the intake air temperature values should display within a few degrees. If the temperatures are not within 3°C (5°F) of each other, refer to Temperature Versus Resistance - Intake Air Temperature Sensor . |
| • | An intermittent malfunction may be caused by a fault in the IAT sensor electrical circuit. Inspect the wiring harness and the components for an intermittent condition. Refer to Intermittent Conditions . |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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The Diagnostic System Check - Vehicle prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
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This step checks for a faulty IAT sensor.
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This step checks the integrity of the IAT sensor input circuit (5-volt reference).
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This step checks the integrity of the IAT sensor ground circuit.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views | ||||
Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | ||
2 |
Is the IAT within the specified value of the ambient air temperature? | 0°C-5°C (0°F-9°F) | Go to Step 3 | Go to Step 4 |
|
Important: Observe the IAT sensor scan tool display continuously while performing the tests below.
Did the scan tool indicate a skip, jump, or a fixed value in the IAT sensor 2 display? | -- | Go to Step 9 | Go to Diagnostic Aids | |
4 |
Does the IAT sensor 2 equal the specified value? | 168°C (334°F) | Go to Step 9 | Go to Step 5 |
Is the resistance less than the specified value? | 0.5 ohms | Go to Step 6 | Go to Step 7 | |
Measure the resistance of the IAT sensor 2 ground circuit from the sensor to the PCM with a DMM. Is the resistance less than the specified value? | 0.5 ohms | Go to Step 10 | Go to Step 8 | |
7 | Repair the short to ground or high resistance in the IAT sensor input circuit between the PCM and the IAT sensor 2. Refer to Wiring Repairs . Is the action complete? | -- | Go to Step 11 | -- |
8 | Repair the open circuit or high resistance in the IAT sensor 2 ground circuit between the PCM and the IAT sensor. Refer to Wiring Repairs . Is the action complete? | -- | Go to Step 11 | -- |
9 | Replace the IAT sensor 2. Refer to Intake Air Temperature Sensor 2 Replacement . Did you complete the replacement? | -- | Go to Step 11 | -- |
10 |
Did you complete the replacement? | -- | Go to Step 11 | -- |
11 |
Does the DTC run and pass? | -- | Go to Step 12 | Go to Step 2 |
12 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK | |
