Circuit Description
The intake air temperature (IAT) sensor is a thermistor which measures the temperature of the air entering the engine. The PCM applies 5 volts through a pull-up resistor to the IAT sensor. When the intake air is cold, the sensor resistance is high, and the PCM will monitor a high signal voltage on the IAT signal circuit. If the intake air is warm, the sensor resistance is lower, causing the PCM to monitor a lower voltage. When the PCM detects an excessively high signal voltage on the intake air temperature sensor signal, circuit. DTC P0113 will set.
Conditions for Running the DTC
| • | No ECT sensor, MAF sensor, or VSS DTCs are present. |
| • | The engine has been running for more than 3 minutes. |
| • | The vehicle speed is less than 35 mph. |
| • | The MAF is less than 12 g/s. |
| • | The engine coolant temperature is more than 60°C (140°F). |
Conditions for Setting the DTC
| • | The IAT signal voltage indicates an IAT that is less than -34°C (-30°F). |
| • | The above conditions are present for at least 20 seconds. |
Action Taken When the DTC Sets
| • | The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed. |
| • | The PCM will store conditions which were present when the DTC set as Freeze Frame/Failure Records data. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn OFF the malfunction indicator lamp (MIL) during the third consecutive trip in which the diagnostic has run and passed. |
| • | The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC can be cleared by using a scan tool. |
Diagnostic Aids
Inspect for the following conditions:
Many situations may lead to an intermittent condition. Perform each inspection or test as directed.
Important: : Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.
| • | Loose terminal connection |
| - | Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair. |
| - | Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair. |
| • | Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair. |
| • | Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair. |
If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.
Test Description
The numbers below refer to the step numbers on the diagnostic table:
-
This step verifies that the fault is present.
-
If DTC P0113 can be repeated only by duplicating the Failure Records conditions, use the Temperature vs Resistance table in order to test the IAT sensor at various temperatures, in order to evaluate the possibility of a shifted sensor that may be open above or below a certain temperature. If this occurs, replace the IAT sensor. If the IAT sensor appears OK, the fault is intermittent. Refer to Diagnostic Aids.
-
Use a fused jumper during this test. If the IAT signal circuit is shorted to battery or shorted to ignition positive voltage, the fuse in the jumper will open, indicating a short in the signal circuit.
-
When the PCM is replaced, you must program the new PCM.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On Board Diagnostic (OBD) System Check? | -- | ||
Is the parameter less than the specified value? | -37°C (-34°F) | |||
Does the DTC reset? | -- | Go to Diagnostic Aids | ||
4 |
Does the parameter measure more than the specified value? | 135°C (275°F) | ||
Does the parameter measure more than the specified value? | 135°C (275°F) | |||
6 | Test the signal circuit of the IAT Sensor for a short to voltage. Repair condition as necessary. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
7 | Test the ground circuit of the IAT Sensor for a high resistance or an open. Repair condition as necessary. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
8 | Test the signal circuit of the IAT Sensor for an open. If a problem is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
9 | Inspect for faulty IAT Sensor ground or signal circuit connections at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Repair condition as necessary. Refer to Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
10 | Inspect for a faulty connections at the IAT Sensor. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Repair condition as necessary. Refer to Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
11 | Replace the IAT Sensor. Refer to Intake Air Temperature Sensor Replacement . Did you complete the replacement? | -- | -- | |
|
Important: You must program the replacement PCM. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Did you complete the replacement? | -- | -- | ||
13 |
Does the DTC reset? | -- | System OK |
