For 1990-2009 cars

### Circuit Description

The manifold absolute pressure (MAP) and the intake air temperature (IAT) sensor 2 are an integrated sensor. The IAT sensor 2 is a variable resistor that measures the temperature of the air entering the engine intake manifold. The powertrain control module (PCM) supplies 5 volts to the IAT sensor 2 signal circuit and a ground for the IAT sensor 2 low reference circuit. When the sensor is cold the resistance is greater. This results in a greater voltage on the signal circuit, that is interpreted by the PCM as a colder IAT. As the sensor becomes warmer the resistance decreases. This results in a lesser voltage on the IAT signal circuit, that is interpreted by the PCM as a warmer IAT. If the PCM detects an IAT sensor 2 signal voltage that is not within a calibrated range of the IAT sensor 1 signal voltage, DTC P0096 sets.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0096 Intake Air Temperature (IAT) Sensor 2 Performance

### Conditions for Running the DTC

• | DTCs P0097, P0098, P0111, P0112, P0113, P0116, P0117 P0118, P0125, P0128 are not set.

• | DTC P0116 must run and pass.

• | The ignition OFF time is greater than 8 hours.

• | The ignition is ON for the initial power-up comparison.

• | This DTC runs once per ignition cycle within the enabling conditions.

### Conditions for Setting the DTC

The PCM detects that the IAT sensor 2 parameter is not within 16°C (29°F) of the IAT Sensor 1 parameter.

### Action Taken When the DTC Sets

• | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.

• | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

### Conditions for Clearing the MIL/DTC

• | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.

• | A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

• | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

• | Clear the MIL and the DTC with a scan tool.

### Diagnostic Aids

Important: Determine the ambient temperature by using an accurate thermometer.

If the ignition has been OFF for 8 hours or more, the IAT Sensor 1 parameter, the IAT Sensor 2 parameter and the ECT Sensor parameter should be within 15°C (27°F) of each other and also the ambient temperature. Turn ON the ignition, and immediately observe the parameters. Compare those sensor parameters to each other and also to the ambient temperature, to determine if the IAT Sensor 2 parameter is skewed.

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Observe the Freeze Frame/Failure Records for this DTC.
2. Turn OFF the ignition for 90 seconds.
3. Start the engine.
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.

Did the DTC fail this ignition?

--

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

3 |

1. Turn OFF the ignition.
2. Disconnect the intake air temperature (IAT) sensor 2.
3. Test for an intermittent and for a poor connection at the IAT sensor 2. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 12

Go to Step 4

4 |

1. Disconnect the powertrain control module (PCM).
2. Test for an intermittent and for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 12

Go to Step 5

5 | Measure the resistance of the IAT sensor 2 signal circuit between the sensor and the PCM with a DMM. Refer to Circuit Testing . Is the resistance within the specified range? | 0-10 ohms | Go to Step 6 | Go to Step 8
6 | Measure the resistance of the IAT sensor 2 low reference circuit between the sensor and the PCM with a DMM. Refer to Circuit Testing Is the resistance within the specified range? | 0-10 ohms | Go to Step 7 | Go to Step 9
7 |

1. Turn OFF the ignition.
2. Remove the IAT sensor 2. Refer to Intake Air Temperature Sensor Replacement .
3. Place the sensor on a work surface away from any heat source.
4. Allow the sensor to reach the ambient air temperature for 30-60 minutes.
5. Observe and record the ambient air temperature of the vehicle environment using an accurate thermometer.
6. Measure the resistance of the IAT sensor 2 and record the value.
7. Compare the resistance measurement of the IAT sensor 2 to the ambient air temperature on the Temperature vs. Resistance table. Refer to Temperature Versus Resistance .

Is the resistance measurement of the IAT sensor 2 within the range specified in the Temperature vs. Resistance table?

--

Go to Step 11

Go to Step 10

8 | Repair the high resistance in the IAT sensor 2 signal circuit . Refer to Wiring Repairs . Did you complete the repair? | -- | Go to Step 12 | --
9 | Repair the high resistance in the IAT sensor 2 low reference circuit . Refer to Wiring Repairs . Did you complete the repair? | -- | Go to Step 12 | --
10 | Replace the IAT sensor 2. Refer to Intake Air Temperature Sensor Replacement . Did you complete the replacement? | -- | Go to Step 12 | --
11 | Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 12 | --
12 |

1. Clear the DTCs with a scan tool.
2. Turn OFF the ignition for 90 seconds.
3. Start the engine.
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.

Did the DTC fail this ignition?

--

Go to Step 2

Go to Step 13

13 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List - Vehicle | System OK