Refer to Engine Controls Schematics
Engine Data Sensors (2 of 2)
.
Circuit Description
The intake air temperature (IAT) sensor is a thermistor that is an integral part of the mass air flow sensor. The IAT sensors resistance is high when the air temperature is cold, and the IAT sensors resistance is low when the air temperature is warm. The IAT sensor is wired in series with a fixed resistor in the powertrain control module (PCM). The PCM applies 5 volts to the IAT sensor. The PCM monitors the voltage across the IAT sensor and converts the voltage into a temperature reading. The PCM will receive a high voltage input when the air temperature is cold. The PCM will receive a low voltage input when the air temperature is warm.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The temperature input is -40°C (-40°F) for at least 0.5 seconds.
OR:
The temperature input is 140°C (284°F) for at least 0.5 seconds.
Action Taken When the DTC Sets
| • | The PCM illuminates the malfunction indicator lamp (MIL). |
| • | The PCM records the operating conditions at the time the diagnostic fails. This information is stored in the Freeze Frame buffer. |
| • | The PCM enters the Fail Safe Function in which the intake air temperature will default to 20°C (68°F). |
Conditions for Clearing the MIL/DTC
| • | The MIL turns OFF after 3 consecutively passing trips without a fault present. |
| • | A History DTC clears after 40 consecutive warm-up cycles without a fault. |
| • | Use the scan tool Clear DTC Information function. |
Diagnostic Aids
Use the Temperature vs Resistance table in order to evaluate the possibility of a shifted IAT sensor. A shifted sensor could result in a DTC P0110. Refer to Temperature Versus Resistance .
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 .
If a DTC P0110 cannot be duplicated, the information included in the Freeze Frame data can be useful in determining vehicle operating conditions when the DTC was first set.
Test Description
The numbers below refer to the step numbers in the diagnostic table.
-
The OBD System Check 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.
-
This step checks for a high input condition. If the scan tool reads 140°C (284°F) the input circuit may shorted to the sensor ground circuit.
-
This step checks for a low input condition. If the scan tool reads -40°C (-40°F) the input circuit may be open.
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This step checks whether the DTC P0110 is the result of a hard failure or an intermittent condition. Operating the vehicle in check mode enhances the PCMs diagnostic capabilities. For additional information on check mode operation refer to the Powertrain Control Module Diagnosis section.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | |||
Select the IAT sensor parameter on the scan tool. Is the IAT sensor value more than or equal to the specified value? | 140°C (284°F) | |||
Select the IAT sensor parameter on the scan tool. Is the IAT sensor value less than or at the specified value? | -40°C (-40°F) | |||
Does the DTC P0110 set? | -- | Go to Diagnostic Aids | ||
5 |
Is the IAT sensor value equal to the specified value? | -40°C (-40°F) | ||
6 |
Is the action complete? | -- | ||
7 |
Is the IAT sensor value more than or equal to the specified value? | 140°C (284°F) | ||
8 |
Is the IAT sensor value more than or equal to the specified value? | 140°C (284°F) | ||
9 |
Was a repair necessary? | -- | ||
10 |
Was a repair necessary? | -- | ||
11 |
Was a repair necessary? | -- | ||
12 |
Was a repair necessary? | -- | ||
13 | Replace the MAF sensor. Refer to Mass Airflow Sensor Replacement . Is the action complete? | -- | -- | |
14 | Replace the PCM. Refer to Powertrain Control Module Replacement . Is the action complete? | -- | -- | |
15 |
Are any DTCs displayed on scan tool? | -- | System OK |
