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DTC P0112, P0113, or P0114

DTC P0112, P0113, or P0114

Diagnostic Instructions


Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Review Strategy Based Diagnosis for an overview of the diagnostic approach.

Diagnostic Procedure Instructions provides 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

DTC P0114

Intake Air Temperature (IAT) Sensor Circuit Intermittent

Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performance
IAT Sensor Signal P0112, P0114 P0113, P0114, P0112 P0113, P0114 P0114
Low Reference - P0113, P0114 P0113, P0114 P0114


Typical Scan Tool Data

IAT Sensor

Circuit Short to Ground Open Short to Voltage
Operating conditions: Engine Running Parameter's normal range: Varies with ambient temperature
IAT Sensor Signal 150°C (302°F) -40°C (-40°F) -40°C (-40°F)*
Low Reference - -40°C (-40°F) -40°C (-40°F)*
*Internal ECM or sensor damage may occur if the circuit is shorted to B+


Circuit/System Description

The intake air temperature (IAT) sensor is a variable resistor. It is integrated into the mass air flow (MAF) sensor. 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 V to the IAT signal circuit, and a ground for the IAT low reference circuit.

Conditions for Running the DTC


P0112

The engine run time is greater than 1 s.

The DTC runs continuously once the above conditions are met.



P0113

The engine run time is greater than 1 s.

The DTC runs continuously once the above conditions are met.



P0114

The ignition is ON or the engine is running.

This DTC runs continuously within the enabling conditions.


Conditions for Setting the DTC

P0112

The ECM detects that the IAT sensor signal is warmer than 149°C (300°F) for greater than 7 s.

P0113

The ECM detects that the IAT sensor signal is colder than -60°C (-76°F) for greater than 7 s.

P0114

The ECM detects that the IAT sensor signal is intermittent or has abruptly changed for greater than 4 s.

Action Taken When the DTC Sets


DTCs P0112, P0113, and P0114 are Type B DTCs.

The ECM commands the cooling fans ON.


Conditions for Clearing the DTC

DTCs P0112, P0113, and P0114 are Type B DTCs.

Diagnostic Aids


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 a DTC P0113 and/or P0114 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 a DTC P0113 and/or P0114 to set.

A MAF sensor ground circuit that is open will cause a DTC P0113 and/or a DTC P0114 to set.


Reference Information

Schematic Reference

Engine Controls Schematics (3.0L (LF1)) Engine Controls Schematics (2.8L (LAU))

Connector End View Reference

Component Connector End Views

Electrical Information Reference


Circuit Testing

Connector Repairs

Testing for Intermittent Conditions and Poor Connections

Wiring Repairs


DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification


1. With the engine running, note the scan tool's parameter for the IAT sensor. The values should be between -40 and +149 °C (-40 and +300 °F) depending on the current ambient temperature and the vehicle's operating conditions.

2. Operate the vehicle within the Conditions for Running the DTC to verify 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


1. Ignition OFF, disconnect the harness connector at the B75B MAF/IAT sensor.

2. Remove the fuse that supplies B+ to terminal 52 X1 of the ECM.

3. 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 Ω between the low reference circuit terminal D and ground.

4. If greater than the specified range, test the low reference circuit for an open/high resistance, or for a short to voltage. If the circuit tests normal, replace the K20 ECM.

5. Install fuse that supplies B+ to terminal 52 X1 of the ECM.

6. Ignition ON, verify the scan tool IAT Sensor parameter is colder than -39°C (-38°F).

7. If greater than the specified range, test the signal circuit's pin E for a short to voltage. If the circuit tests normal, replace the K20 ECM.

8.
Note

If the fuse in the jumper wire opens, the signal circuit is shorted to voltage and the sensor may be damaged.


Install a 3 A fused jumper wire between the signal circuit terminal E and ground. Verify the scan tool IAT parameter is greater than 149°C (300°F).

9. If less 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 K20 ECM.

10. If all circuits test normal, test or replace the B75B MAF/IAT sensor.


Component Testing

Measure and record the resistance of the B66 IAT sensor at various ambient temperatures, then compare those measurements to the Temperature Versus Resistance - Intake Air Temperature Sensor table.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.


Mass Airflow Sensor with Intake Air Temperature Sensor Replacement (LAU) Mass Airflow Sensor with Intake Air Temperature Sensor Replacement (LF1)

Control Module References for ECM replacement, setup, and programming