P0113

DTC P0113

DTC DESCRIPTOR

DTC P0112
Intake Air Temperature (IAT) Sensor Circuit Low Voltage

DTC P0113
Intake Air Temperature (IAT) Sensor Circuit High Voltage

DIAGNOSTIC FAULT INFORMATION

IMPORTANT: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Testing and Inspection






TYPICAL SCAN TOOL DATA

IAT Sensor:

CIRCUIT/SYSTEM DESCRIPTION
The intake air temperature (IAT) sensor is a variable resistor. The IAT sensor has a signal circuit and a low reference circuit. The IAT sensor measures the temperature of the air entering the engine. The engine control module (ECM) supplies 5 volts to the IAT signal circuit, and a ground for the IAT low reference circuit. When the IAT sensor is cold, the sensor resistance is high. When the air temperature increases, the sensor resistance decreases. With high sensor resistance, the ECM detects a high voltage on the IAT signal circuit. With lower sensor resistance, the ECM detects a lower voltage on the IAT signal circuit.

CONDITIONS FOR RUNNING THE DTC

DTC P0112
- DTC P0117, P0118, P0116, P0125, P0128, P0608, or P0609 are not set.
- The ECT sensor is less than 150°C (302°F).
- The engine run time is more than 10 seconds.
- DTC P0112 runs continuously within the above enable conditions.

DTC P0113
- DTC P0101, P0102, P0103, P0117, P0118, P0116, P0125, P0128, P0608, or P0609 are not set.
- The ECT sensor is less than -40°C (-40°F).
- The mass air flow (MAF) sensor is less than 512 g/s.
- The engine run time is more than 10 seconds.
- DTC P0112 runs continuously within the above enable conditions.

CONDITIONS FOR SETTING THE DTC

DTC P0112
The IAT sensor is more than 148°C (298°F) for more than 5 seconds.

DTC P0113
The IAT sensor is less than -39°C (-38°F) for more than 5 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.

CIRCUIT/SYSTEM VERIFICATION

IMPORTANT: If you cannot duplicate the condition, 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.

Perform this procedure only when the ignition has been OFF for eight hours or more.

IMPORTANT: The IAT will begin to warm up as soon as the ignition key is turned ON

Turn ON the ignition, with the engine OFF. Use a scan tool to observe and compare the IAT and ECT parameters. The IAT and the ECT should be within 6°C (11°F) of each other and the ambient temperature.

CIRCUIT/SYSTEM TESTING

DTC P0112
1. With the ignition ON, the engine OFF, and the MAF/IAT sensor harness disconnected, observe the IAT sensor parameter with a scan tool for a value of less than -39°C (-38°F).
- If the IAT sensor parameter is less than -39°C (-38°F), replace the IAT sensor.
- If the IAT sensor parameter is more than 148°C (298°F), test the IAT sensor signal circuit for a short to ground or a faulty ECM.

DTC P0113
1. With the ignition ON, the engine OFF, and the IAT sensor harness disconnected, measure for a voltage range of 4.8-5.2 volts between the IAT signal circuit and a ground.
- If the voltage is more than 5.2 volts, test the IAT sensor signal circuit for a short to voltage or a faulty ECM.
- If the voltage is less than 4.8 volts, test the IAT sensor signal circuit for an open, high resistance, or a faulty ECM.
2. Measure the voltage between the IAT low reference circuit and the IAT signal circuit.
- If the voltage is less than 4.8 volts, test the IAT low reference circuit for an open, high resistance, or a faulty ECM.
3. With the ignition ON, the engine OFF, and the IAT sensor harness disconnected, observe the scan tool IAT temperature parameter for a value of less than -39°C (-38°F). Connect a 3-amp fused jumper wire between the signal circuit and low reference circuit. Observe the scan tool IAT temperature parameter for a value of more than 148°C (298°F).
- If the temperature is more than 148°C (298°F), test the IAT signal circuit for a short to a 5-Volt reference circuit.
4. If the IAT sensor circuits test normal, replace the IAT sensor.

COMPONENT TESTING
Compare the IAT sensor resistance to the values listed in the Temperature vs. Resistance table. Refer to Temperature vs Resistance.
- If the resistance is not within the range listed in the Temperature vs. Resistance table, replace the IAT sensor.

REPAIR INSTRUCTIONS

IMPORTANT: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
- Mass Air Flow (MAF)/Intake Air Temperature (IAT) Sensor Replacement
- Control Module References for ECM replacement, setup, and programming Verification Tests