| 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
The intake air temperature sensor, in the mass air flow meter sub-assembly, monitors the intake air temperature. The intake air temperature sensor has a built-in thermistor with a resistance that varies according to the temperature of the intake air. When the intake air temperature becomes low, the resistance of the thermistor increases. When the temperature becomes high, the resistance drops. These variations in resistance are transmitted to the ECM as voltage changes (see Fig. 1).
The intake air temperature sensor is powered by a 5 V supply from the THA terminal of the ECM, via resistor R which is located inside the ECM.
Resistor R and the intake air temperature sensor are connected in series. When the resistance value of the intake air temperature 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.
When any of DTCs P0110, P0112 or P0113 are set, the ECM enters fail-safe mode. During fail-safe mode, the intake air temperature 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 | Open or short in intake air temperature sensor circuit for 0.5 seconds (1 trip detection logic) |
|
| P0112 | Short in intake air temperature sensor circuit for 0.5 seconds (1 trip detection logic) |
|
| P0113 | Open in intake air temperature sensor circuit for 0.5 seconds (1 trip detection logic) |
|
When any of these DTCs are set, check the intake air temperature by entering the following menus on the intelligent tester: Powertrain / Engine and ECT / Data List / All Data / Intake Air.
| Temperature Displayed | Malfunction |
|---|---|
| -40°C (-40°F) | Open circuit |
| 140°C (284°F) or more | Short circuit |
INSPECTION PROCEDURE
Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.
PROCEDURE
READ VALUE USING INTELLIGENT TESTER (INTAKE AIR)
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG).
Turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Intake Air.
Read the value displayed on the tester.
| Standard |
|---|
| Same as actual intake air temperature. |
| Result | ||||||||
|---|---|---|---|---|---|---|---|---|
|
If there is an open circuit, the intelligent tester indicates -40°C (-40°F).
If there is a short circuit, the intelligent tester indicates 140°C (284°F) or more.
READ VALUE USING INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS)
Confirm good connection at the mass air flow meter sub-assembly.
| *1 | Mass Air Flow Meter Sub-assembly | *2 | ECM |
| *3 | Front view of wire harness connector (to Mass Air Flow Meter Sub-assembly) |
- | - |
Disconnect the mass air flow meter sub-assembly connector.
Connect terminals THA and E2 of the mass air flow meter sub-assembly connector on the wire harness side.
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG).
Turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Intake Air.
Read the value displayed on the tester.
| Standard |
|---|
| 140°C (284°F) or more |
Reconnect the mass air flow meter sub-assembly connector.
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)
Disconnect the mass air flow meter sub-assembly connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance (Check for Open) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Reconnect the mass air flow meter sub-assembly connector.
Reconnect the ECM connector.
READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS)
Disconnect the mass air flow meter sub-assembly connector.
| *1 | Mass Air Flow Meter Sub-assembly |
| *2 | ECM |
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG).
Turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Intake Air.
Read the value displayed on the tester.
| Standard |
|---|
| -40°C (-40°F) |
Reconnect the mass air flow meter sub-assembly connector.
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)
Disconnect the mass air flow meter sub-assembly connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance (Check for Short) | ||||||
|---|---|---|---|---|---|---|
|
Reconnect the mass air flow meter sub-assembly connector.
Reconnect the ECM connector.
CHECK FOR INTERMITTENT PROBLEMSClick here
REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)
REPLACE MASS AIR FLOW METER SUB-ASSEMBLYClick here
REPLACE ECMClick here