• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage |
---|---|---|---|
IAT Sensor Signal | P0112 | P0113 | P0113 |
Low Reference | -- | P0113 | P0113 |
Circuit | Short to Ground | Open or High Resistance | Short to Voltage |
---|---|---|---|
Operating Conditions: Engine running Normal IAT Parameter: -39 to +120°C (-38 to +248°F) | |||
IAT Sensor Signal | 149°C (300°F) | -40°C (-40°F) | -40°C (-40°F |
IAT Low Reference | -- | -40°C (-40°F) | -40°C (-40°F) |
The intake air temperature (IAT) sensor is a variable resistor that 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 to the low reference circuit.
• | 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 seconds. |
• | This DTC runs continuously within the above enable conditions. |
• | 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 seconds. |
• | This DTC runs continuously within the above enable conditions. |
The IAT sensor is greater than 148°C (298°F) for greater than 5 seconds.
The IAT sensor is less than -39°C (-38°F) for greater than 5 seconds.
DTCs P0112 and P0113 are Type B DTCs.
DTCs P0112 and P0113 are Type B DTCs.
• | 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. |
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
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.
Important: All electrical components and accessories must be turned OFF and allowed to power down.
⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If greater than the specified range, test the signal circuit terminal D 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. |
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 .
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for ECM replacement, setup, and programming |