P0111
DTC P0111
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 ECM/PCM. The ECM/PCM applies 5 V to the IAT sensor. The ECM/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 ECM/PCM will receive a high voltage input, and when the air temperature is warm the ECM/PCM will receive a low voltage input. The signal from IAT sensor is used for injection duration correction, ignition timing correction and idle speed correction (Air density correction).
DTC DESCRIPTION
If measured temperature is satisfied with threshold value during 10 sec, ECM/PCM sets DTC P0111.
DTC Detecting Condition:
Specification:
Schematic Diagram - A/T:
Schematic Diagram - M/T:
MONITOR SCANTOOL DATA
1. Connect scantool to DLC(Data Link Cable).
2. Warm up the engine to normal operating temperature.
3. Monitor "IATS" & "ECTS" parameter on scantool.
4. Is the "IATS" & "ECTS" parameter displayed correctly?
YES - Fault is intermittent caused by poor contact in the sensor's and/or PCM's connector or was repaired and ECM/PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, ending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
NO
- If there is faulty on "ECTS" circuit or itself, check "ECTS" circuit or itself according to the designated "ECTS" troubleshooting guide.
- If there is not faulty on "ECTS" circuit or itself, Go to "Inspection & Repair" procedure.
TERMINAL AND CONNECTOR INSPECTION
1. Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES - Repair as necessary and go to "Verification of vehicle Repair" procedure.
NO - Go to " Signal Circuit Inspection " procedure.
SIGNAL CIRCUIT INSPECTION
1. IG "OFF".
2. Disconnect IATS connector.
3. IG "ON"& ENG "OFF".
4. Measure voltage between terminal 5 of IATS harness connector and chassis ground.
Specification : Approx. 5 V
5. Is the measured voltage within specification?
YES - Go to "Ground Circuit Inspection" procedure.
NO - Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.
GROUND CIRCUIT INSPECTION
1. IG "OFF".
2. Disconnect IATS connector.
3. IG "ON"& ENG "OFF"
4. Measure voltage between terminal 5 of IATS harness connector and chassis ground.(A)
5. Measure voltage between terminal 1 and 5 of IATS harness connector.(B)
Specification : "A" - "B" = Below 200 mV
6. Is the measured voltage within specification?
YES - Go to "Component Inspection" procedure.
NO - Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.
COMPONENT INSPECTION
1. Check IATS resistance.
a. IG "OFF".
b. Disconnect IATS connector.
Specification:
c. Measure resistance between terminal 1 and 5 of IATS connector.(Component Side)
d. Is the measured resistance within specification ?
YES - Go to "Check PCM" as follows.
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.
2. Check ECM/PCM.
a. IG "OFF".
b. Connect scantool and Engine "ON".
c. Select simulation function on scantool.
d. Simulate voltage at terminal 5 of IATS signal connector.
e. Does the signal value of IATS change according to simulation voltage?
YES - Thoroughly check connectors for looseness, poor connection, bending, corrosion,contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
NO
- Substitute with a known - good ECM/PCM and check for proper operation.
- If the problem is corrected, replace ECM/PCM 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 scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.
2. Clear the DTCs and Operate the vehicle within DTC Enable conditions in General information.
3. Are any DTCs present ?
YES - Go to the applicable troubleshooting procedure.
NO - System is performing to specification at this time.