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 provide an overview of each diagnostic category. |
DTC Descriptor
DTC P0114: Intake Air Temperature (IAT) Sensor Circuit IntermittentDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
IAT Sensor Signal | P0112 | P0113, P0114 | P0113¹, P0114 | P0111¹ |
Low Reference | -- | P0113, P0114 | P0113², P0114 | P0111¹ |
¹ Sensor damage may occur if the circuit is shorted to B+. ² Internal ECM damage may occur if the circuit is shorted to B+. | ||||
Typical Scan Tool Data
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Operating Conditions: Engine operating in Closed Loop. Parameter Normal Range: Varies with ambient air temperature and engine operation. | |||
IAT Sensor Signal | 128°C (248°F) | -40°C (-40°F) | -40°C (-40°F)¹ |
Low Reference | -- | -40°C (-40°F) | -40°C (-40°F)¹ |
¹ Internal ECM or sensor damage may occur if the circuit is shorted to B+. | |||
Circuit Description
The intake air temperature (IAT) sensor is a variable resistor that measures the temperature of the air entering the engine. The IAT sensor has a signal circuit and a low reference circuit. The engine control module (ECM) supplies 5 volts to the IAT signal circuit and a ground for the IAT low reference circuit.
The following table illustrates the difference between temperature, resistance, and voltage:
Temperature | IAT Resistance | IAT Signal Voltage |
|---|---|---|
Cold | High | High |
Warm | Low | Low |
Conditions for Running the DTC
| • | The ignition is ON. |
| • | DTC P0114 runs continuously once the above condition is met. |
Conditions for Setting the DTC
The difference between the calculated IAT and the actual IAT is greater than 8°C (14°F) for at least 10 seconds.
Action Taken When the DTC Sets
DTC P0114 is a Type B DTC.
Conditions for Clearing the MIL/DTC
DTC P0114 is a Type B DTC.
Diagnostic Aids
If the vehicle has sat overnight, the IAT sensor and the engine coolant temperature (ECT) sensor values should display within 3°C (6°F).
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Circuit/System Verification
- Ignition ON, observe the IAT sensor parameter with a scan tool while moving the IAT sensor connector and the ECM connector. The reading should not fluctuate while moving the related harnesses and connectors.
- Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.
Circuit/System Testing
- Ignition ON, observe the scan tool IAT sensor parameter while moving the IAT sensor connector and the ECM connector. The reading should not fluctuate while moving the related harnesses and connectors.
- Ignition OFF, disconnect the harness connector at the IAT sensor.
- Ignition ON, verify the scan tool IAT sensor parameter is at -40°C (-40°F).
- Install a 3-A fused jumper wire between the signal circuit and the low reference circuit. Verify the scan tool IAT sensor parameter is greater than 125°C (240°F).
- If all circuits test normal, test or replace the IAT sensor.
| ⇒ | If the reading fluctuates while moving the harness, repair the appropriate harness/connector. |
| ⇒ | If greater than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM. |
| ⇒ | 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 ECM. |
Component Testing
- Ignition OFF, disconnect the harness connector at the IAT sensor.
- Test the sensor by varying the sensor temperature while monitoring the sensor resistance.
- Compare the readings with the Temperature Versus Resistance table and verify that the resistance is within 5 percent of the specification.
Important: A thermometer can be used to test the sensor off the vehicle.
| ⇒ | If not within the specified range, replace the IAT sensor. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for engine control module replacement, setup, and programming |
