SFI SYSTEM, Diagnostic DTC:P0110, P0112, P0113
| DTC Code | DTC Name |
|---|---|
| P0110 | Intake Air Temperature Circuit Malfunction |
| P0112 | Intake Air Temperature Circuit Low Input |
| P0113 | Intake Air Temperature Circuit High Input |
DESCRIPTION
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The Intake Air Temperature (IAT) sensor, built into the Mass Air Flow (MAF) meter, monitors the IAT. The IAT sensor has a built-in thermistor with a resistance that varies according to the temperature of the intake air. When the IAT is low, the resistance of the thermistor increases. When the temperature is high, the resistance drops. These variations in resistance are transmitted to the ECM as voltage changes (see Fig. 1).
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The IAT sensor is powered by a 5 V supply from the THA terminal of the ECM, via resistor R.
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Resistor R and the IAT sensor are connected in series. When the resistance value of the IAT sensor changes, the voltage at terminal THA varies accordingly. Based on this signal, the ECM increases the fuel injection volume when the engine is cold to improve driveability.
Tech Tips
When DTC P0110, P0112 or P0113 is stored, the ECM enters fail-safe mode. During fail-safe mode, the IAT is estimated to be 20°C (68°F) by the ECM. Fail-safe mode continues until a pass condition is detected.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0110 | An open or short in the IAT sensor circuit for 0.5 seconds (1 trip detection logic). |
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| P0112 | A short in the IAT sensor circuit for 0.5 seconds (1 trip detection logic). |
|
| P0113 | An open in the IAT sensor circuit for 0.5 seconds (1 trip detection logic). |
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Tech Tips
When any of these DTCs are stored, check the IAT using the intelligent tester. Enter the following menus: Powertrain / Engine and ECT / Data List / Intake Air.
| Temperature Displayed | Malfunction |
|---|---|
| -40°C (-40°F) | Open circuit |
| 140°C (284°F) or higher | Short circuit |
WIRING DIAGRAM
INSPECTION PROCEDURE
Tech Tips
Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.
PROCEDURE
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READ VALUE USING INTELLIGENT TESTER (INTAKE AIR TEMPERATURE)
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Connect the intelligent tester to the DLC3.
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Turn the engine switch on (IG) and turn the tester on.
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Enter the following menus: Powertrain / Engine and ECT / Data List / Intake Air.
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Read the value displayed on the tester.
Standard Same as actual Intake Air Temperature (IAT). Result Result Proceed to -40°C (-40°F) A 140°C (284°F) or higher B Same as actual IAT C Tech Tips
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If there is an open circuit, the intelligent tester indicates -40°C (-40°F).
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If there is a short circuit, the intelligent tester indicates 140°C (284°F) or higher.
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B 
READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS) Click here
C 
CHECK FOR INTERMITTENT PROBLEMS Click here
A 
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READ VALUE USING INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS)
Text in Illustration *1 MAF Meter *2 ECM *3 Front view of wire harness connector
(to MAF Meter)
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Disconnect the B2 Mass Air Flow (MAF) meter connector.
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Connect terminals THA and E2 of the MAF meter wire harness connector.
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Connect the intelligent tester to the DLC3.
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Turn the engine switch on (IG) and turn the tester on.
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Enter the following menus: Powertrain / Engine and ECT / Data List / Intake Air.
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Read the value displayed on the tester.
Standard value 140°C (284°F) or higher -
Reconnect the MAF meter connector.
NG
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) Click here
OK 
CONFIRM GOOD CONNECTION TO MASS AIR FLOW METER. IF OK, REPLACE MASS AIR FLOW METER Click here
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CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
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Text in Illustration *1 Front view of wire harness connector
(to MAF Meter)
*2 Front view of wire harness connector
(to ECM)
Disconnect the B2 MAF meter connector.
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Disconnect the B39 ECM connector.
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Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Condition Specified Condition B2-1 (THA) - B39-65 (THA) Always Below 1 Ω B2-2 (E2) - B39-88 (ETHA) -
Reconnect the MAF meter connector.
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Reconnect the ECM connector.
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
CONFIRM GOOD CONNECTION TO ECM. IF OK, REPLACE ECM Click here
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READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS)
Text in Illustration *1 MAF Meter *2 ECM
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Disconnect the B2 MAF meter connector.
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Connect the intelligent tester to the DLC3.
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Turn the engine switch on (IG) and turn the tester on.
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Enter the following menus: Powertrain / Engine and ECT / Data List / Intake Air.
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Read the value displayed on the tester.
Standard value -40°C (-40°F) -
Reconnect the MAF meter connector.
NG
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) Click here
OK
REPLACE MASS AIR FLOW METER Click here
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CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
Text in Illustration *1 Front view of wire harness connector
(to MAF Meter)
*2 Front view of wire harness connector
(to ECM)
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Disconnect the B2 MAF meter connector.
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Disconnect the B39 ECM connector.
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Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Condition Specified Condition B2-1 (THA) or B39-65 (THA) - Body ground Always 10 kΩ or higher -
Reconnect the MAF meter connector.
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Reconnect the ECM connector.
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
REPLACE ECM Click here
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