Circuit Description
The intake air temperature (IAT) sensor is a thermistor that controls signal voltage to the powertrain control module (PCM). When the air is cold, the sensor resistance is high, therefore the PCM will see a high signal voltage. As air warms, the sensor resistance becomes less and the voltage decreases.
Conditions for Running the DTC
The engine has been operating for at least 8 minutes.
Conditions for Setting the DTC
| • | The IAT is less than or equal to -40°C (-40°F). |
| • | The conditions are met for 2 seconds. |
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
The scan tool displays intake air temperature in degrees Celsius. Refer to Symptoms - Engine Controls . A skewed sensor could result in poor driveability complaints. Refer to Temperature Versus Resistance .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step determines if DTC P0113 is a hard failure or an intermittent condition.
-
This step will determine if there is a wiring condition or a malfunctioning PCM.
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This step determines if there is a short to voltage on the signal circuit. A short to voltage increases current flow through the sensor which "overwhelms" the sensor. This does not allow the sensor to pull down the circuit to the correct voltage and thus display the correct temperature.
-
After repairing the short to voltage, check the sensor for proper operation.
Step
| Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |
Does the scan tool display a temperature less than or equal to the specified value? | -30°C (-22°F) | Go to Step 3 | Go to Step 5 | |
Does the scan tool display an IAT temperature that is more than or equal to the specified value? | 151°C (303°F) | Go to Step 6 | Go to Step 4 | |
4 | Jumper the IAT sensor signal circuit at the sensor harness connector to a known good ground. Does the scan tool display an IAT temperature more than or equal to the specified value? | 151°C (303°F) | Go to Step 7 | Go to Step 8 |
5 | The DTC is intermittent. If no other DTCs are stored, refer to Diagnostic Aids. Are there any other DTCs stored? | -- | Go to Diagnostic Aids | |
6 |
Did you complete the repair? | -- | Go to Step 14 | Go to Step 9 |
7 |
Did you complete the repair? | -- | Go to Step 14 | Go to Step 11 |
8 |
Did you complete the repair? | -- | Go to Step 14 | Go to Step 11 |
With a DMM, set to the mA scale, measure the current at the IAT harness connector terminals. Is the current less than the specified value? | 50 mA | Go to Step 12 | Go to Step 10 | |
Repair the short to voltage on the IAT signal circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 14 | -- | |
11 | Inspect the PCM connectors for faulty connections and replace the terminals if necessary. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 14 | Go to Step 13 |
12 | Replace the IAT sensor. Refer to Intake Air Temperature Sensor Replacement . Did you complete the replacement? | -- | Go to Step 14 | -- |
13 | Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | Go to Step 14 | -- |
14 |
Does the scan tool indicate the diagnostic passed? | -- | Go to Step 15 | Go to Step 2 |
15 | Does the scan tool display any additional undiagnosed DTCs? | -- | System OK | |
