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 P0110: Intake Air Temperature (IAT) Sensor 1 CircuitDTC P0110 09: Intake Air Temperature (IAT) Sensor 1 Circuit Rate of Change Above Threshold
DTC P0110 0A: Intake Air Temperature (IAT) Sensor 1 Circuit Rate of Change Below Threshold
DTC P0110 11: Intake Air Temperature (IAT) Sensor 1 Circuit Above Maximum Threshold
DTC P0110 12: Intake Air Temperature (IAT) Sensor 1 Circuit Below Minimum Threshold
Circuit Description
The intake air temperature (IAT) sensor 1 is an integral part of the mass air flow (MAF) sensor. The IAT sensor is a variable resistor that measures the temperature of the intake air. The engine control module (ECM) supplies 5 volts to the IAT signal circuit and supplies a ground to the 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 ignition is ON or the engine is operating. |
| • | The ignition voltage is greater than 8.5 volts. |
| • | The DTCs run continuously once the above conditions are met. |
Conditions for Setting the DTC
P0110
The ECM detects that an IAT 1 circuit is open, shorted to ground or voltage.
P0110 11
The ECM detects that the duty cycle of IAT 1 signal is greater than 90 percent.
P0110 12
The ECM detects that the duty cycle of IAT 1 signal is less than 10 percent.
Action Taken When the DTC Sets
DTC P0110 is a Type B DTC.
Conditions for Clearing the MIL/DTC
DTC P0110 is a Type B DTC.
Diagnostic Aids
| • | If the engine has sat overnight, the IAT sensor and the ECT sensor values should display within 3°C (5°F). |
| • | High resistance on either the IAT sensor signal circuit or the IAT sensor low reference circuit could set a 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
Circuit/System Verification
Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. DTC P0110 should not set.
Circuit/System Testing
- Ignition OFF, and the MAIN fuse removed, disconnect the harness connector at the MAF/IAT sensor.
- Test for less than 5 ohms of resistance between the low reference circuit terminal 2 and ground.
- Install the MAIN fuse. Ignition ON, test for 4.8-5.2 volts between the IAT signal circuit terminal 3 and ground.
- If all circuits/connections test normal, test or replace the MAF/IAT sensor.
| ⇒ | 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/connections test normal, replace the engine control module (ECM). |
| ⇒ | If less than the specified range, test the signal circuit for an open or a short to ground. If the circuit/connections test normal, replace the ECM. |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit/connections test normal, replace the ECM. |
Component Testing
Measure and record the resistance between the signal circuit terminal 3 and the low reference circuit terminal 2 at various ambient temperatures. Compare those measurements to the Temperature Versus Resistance table and verify that the resistance is within 5 percent of the specification.
| ⇒ | 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 engine control module replacement, setup, and programming |
Repair Verification
Ignition ON, observe the scan tool DPF soot mass parameter. The parameter should be less than 24 grams.
| ⇒ | If greater than the specified range, perform a DPF service regeneration. Refer to Exhaust Particulate Filter Cleaning . |
