P0110
DTC P0110 INTAKE AIR TEMPERATURE SENSOR1 CIRCUITComponent Location:
GENERAL DESCRIPTION
The Intake Air Temperature (IAT) sensor measures the temperature of engine intake air. The intake Air Temperature (IAT) sensor is a thermistor (a variable resistor that changes along with outside air temperature) in series with a fixed resistor in the PCM. The PCM applies 5 volts to the IAT sensor. The PCM monitors the voltage across the IAT sensor and converts it into a temperature reading. When the outside air temperature is cold the IAT sensor resistance is high, and when the outside air temperature is warm the IAT sensor resistance is low. Therefore, when the air temperature is cold the PCM will receive a high voltage input, and when the air temperature is warm the PCM will receive a low voltage input. The signal from IAT sensor is used for injection time correction (Cold post start correction), ignition angle correction (Air temperature correction) and idle speed correction (Air-density correction).
DTC DESCRIPTION
PCM monitors temperature difference between MAX. and MIN IATS in order to detect movement in IATS not only Start Test but Drive Test while enable condition is met. If PCM detects intake air temperature changes less than 5.4°F , PCM determines that a fault exists and a DTC is stored. MIL (Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.
DTC Detecting Condition:
Specification:
Schematic Diagram:
Signal Waveform And Data:
SIGNAL WAVEFORM AND DATA
The output signals of IATS & ECTS change smoothly without any rapid changes. Those have almost same characteristic signal during the early period after start. It means that the temperatures of intake air and engine coolant are depended on the temperature of atmosphere. Meanwhile, during the warming up, the output signal of ECTS is going up increasingly. But, the output signal of IATS changes a little bit. Even it may not change almost. It means that the heat of engine does not affect on the temperature of intake air.
MONITOR SCANTOOL DATA
1. Connect scantool to Data Link Connector (DLC).
2. IG "ON".
3. Select "Diagnostic Trouble Codes (DTCs)" mode, and then Press F4 (DTAL) to check DTC's information from the DTCs menu.
4. Read "DTC Status" parameter.
5. Is parameter displayed "Present fault"?
YES - Go to "Component Inspection" procedure.
NO - Fault is intermittent caused by PCM memory was not cleared after repair. Erase DTC and drive the vehicle to satisfy the enable condition then, go to " Component Inspection" procedure.
COMPONENT INSPECTION
1. Check resistance of IATS
1. IG "OFF" and disconnect IATS connector.
Specification:
2. Measure resistance between terminal 4 and 5 of IATS connector after checking out the temperature of IATS with scantool.
3. Is the measured resistance within specification?
YES - Go to "Verification of Vehicle Repair" procedure.
NO - Substitute with a known - good IATS and check for proper operation. If the problem is corrected, replace IATS and go to "Verification of Vehicle Repair" procedure.
VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scantool and select "Diagnostic Trouble Codes (DTCs)" mode
2. Press F4 (DTAL) and confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions
3. Read "DTC Status" parameter.
4. Is parameter displayed "History (Not Present) fault"?
YES - System performing to specification at this time. Clear the DTC.
NO - Go to the applicable troubleshooting procedure.