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 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 | P0113 | P0114 |
Low Reference | -- | P0113 | P0113 | P0114 |
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 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 Description
The intake air temperature (IAT) sensor is an integral part of the mass air flow (MAF) sensor. 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:
IAT | IAT Resistance | IAT Signal Voltage |
|---|---|---|
Cold | High | High |
Warm | Low | Low |
Conditions for Running the DTC
| • | The engine is running. |
| • | The DTC runs continuously once the above condition is met. |
Conditions for Setting the DTC
The ECM detects that the IAT sensor signal varies greater than 10°C (18°F) between each consecutive sample for greater than 20 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.
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Engine idling, observe the diagnostic trouble code (DTC) information with a scan tool. DTCs P0112 or P0113 should not be set.
- Engine idling, observe the scan tool IAT Sensor parameter while moving the related wiring harness and harness connectors. The reading should not change abruptly.
- If all circuits test normal, test or replace the MAF/IAT sensor.
| ⇒ | If a DTC is set, refer to DTC P0112 or P0113 for further diagnosis. |
| ⇒ | If the reading changes abruptly, repair the wiring harness or the harness connectors. |
Component Testing
- Ignition OFF, disconnect the harness connector at the MAF/IAT sensor.
- Test the IAT 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.
Note: A thermometer can be used to test the sensor off the vehicle.
| ⇒ | If not within the specified range, replace the MAF/IAT sensor. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for ECM replacement, setup, and programming. |
