P0110

DTC P0110

CIRCUIT DESCRIPTION




The DTC P0110 Intake Air Temperature (IAT) Sensor Circuit diagnostic detects an out of range sensor signal. The IAT sensor is a thermistor that is an integral part of the mass air flow (MAF) sensor. The electrical resistance of the IAT sensor is high when the air temperature is cold, and the resistance is low when the air temperature is warm. The IAT sensor is wired in series with a fixed resistor located 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 voltage measured by the PCM will be high when the air temperature is cold, and low when the air temperature is warm.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P0110 Intake Air Temperature (IAT) Sensor Circuit

CONDITIONS FOR RUNNING THE DTC
- The ignition is ON.
- DTC P0110 runs continuously once the above condition has been met.

CONDITIONS FOR SETTING THE DTC
- The temperature input is -40°C (-40°F), 4.91 volts, for at least 0.5 seconds. OR
- The temperature input is 140°C (284°F), 0.18 volts, 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 PCM turns OFF the MIL after 3 consecutive trips without a fault.
- The PCM clears a History DTC 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 vs 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.

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

Step 1 - Step 11:

Step 12 - Step 16:

The numbers below refer to the step numbers on the diagnostic table.
1. 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.
2. 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.
3. This step checks for a low input condition. If the scan tool reads -40°C (-40°F) the input circuit may be open.
4. 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 PCM diagnostic capabilities. For additional information on check mode operation refer to the Powertrain Control Module Diagnosis section.