P0112
DTC P0112 or P0113
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions)provide an overview of each diagnostic category.
DTC Descriptors
DTC P0112
- Intake Air Temperature (IAT) Sensor Circuit Low Voltage
DTC P0113
- Intake Air Temperature (IAT) Sensor Circuit High Voltage
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The mass air flow (MAF) sensor is integrated with the intake air temperature (IAT) sensor. The IAT sensor is a variable resistor that measures the temperature of the air entering the engine. The engine control module (ECM) supplies 5 V to the IAT signal circuit, and a ground to the low reference circuit.
Conditions for Running the DTC
P0112
* DTC P0116, P0117, P0118, P0125, P0128, P0608, or P0609 are not set.
* The ECT sensor is less than 150°C (302°F).
* The engine run time is greater than 10 s.
* This DTC runs continuously within the above enable conditions.
P0113
* DTC P0101, P0102, P0103, P0116, P0117, P0118, P0125, P0128, P0608, or P0609 are not set.
* The ECT sensor is greater than -40°C (-40°F).
* The mass air flow (MAF) sensor is less than 512 g/s.
* The engine run time is greater than 10 s.
* This DTC runs continuously within the above enable conditions.
Conditions for Setting the DTC
P0112
The IAT sensor is greater than 148°C (298°F) for greater than 5 s.
P0113
The IAT sensor is less than -39°C (-38°F) for greater than 5 s.
Action Taken When the DTC Sets
DTCs P0112 and P0113 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs P0112 and P0113 are Type B DTCs.
Diagnostic Aids
* If the engine is cold at the initial ignition ON, a properly functioning IAT sensor will gradually increase the scan tool IAT Sensor parameter. This is due to the heat that is generated by the MAF sensor heating elements.
* Depending on the ambient temperature, an IAT sensor signal circuit or low reference circuit that is shorted to the MAF sensor signal circuit can cause DTC P0113 to set. This condition causes a rapid fluctuation in the IAT Sensor parameter.
* An IAT sensor signal circuit that is shorted to the MAF sensor ignition circuit can cause DTC P0113 to set.
Reference Information
Schematic Reference
Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference
Control Module References (Programming and Relearning)for scan tool information
Circuit/System Verification
Important:
* Perform this procedure only when the ignition has been OFF for 8 hours or more.
* The IAT will begin to warm up as soon as the ignition key is turned ON.
1. Engine running, observe the scan tool IAT Sensor parameter. The reading should be between -39 to +120°C (-38 to +248°F) depending on the current ambient temperature and the vehicle operating conditions.
2. Ignition ON, observe the scan tool IAT and ECT Sensor parameters. The readings should be within 15°C (27°F) of each other and the ambient temperature.
3. Ignition ON, observe the scan tool Start-up ECT and Start-up IAT Sensor parameters. Compare those sensor parameters to each other and also to the ambient temperature to determine if the IAT sensor is within an acceptable operating range.
4. Engine running, observe the DTC information with a scan tool. DTCs P0112 or P0113 should not set.
5. Operate the vehicle within the Conditions for Running the DTC to verify that the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
Important: All electrical components and accessories must be turned OFF and allowed to power down.
1. Ignition OFF, disconnect the harness connector at the MAF/IAT sensor.
2. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohm of resistance between the low reference circuit terminal E and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
3. Ignition ON, verify the scan tool IAT Sensor parameter is colder than -39°C (-38°F).
• If warmer than the specified range, test the signal circuit terminal D for a short to ground. If the circuit tests normal, replace the ECM.
4. Ignition ON, test for 4.8-5.2 V between the signal circuit terminal D and ground.
• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
5. Install a 3A fused jumper wire between the signal circuit terminal D and ground. Verify the scan tool IAT Sensor parameter is warmer than 149°C (300°F).
• If colder than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
6. If all circuits test normal, test or replace the MAF/IAT sensor.
Component Testing
Measure the resistance of the IAT sensor and compare the IAT sensor resistance to the values listed in the Temperature vs. Resistance table. Refer to Temperature Versus Resistance (Temperature Versus Resistance).
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Mass Airflow Sensor with Intake Air Temperature Sensor Replacement (Service and Repair)
* Control Module References (Programming and Relearning)for ECM replacement, setup, and programming