DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
READ VALUE USING INTELLIGENT TESTER (INTAKE AIR TEMPERATURE)
READ VALUE USING INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS)
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS)
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
REPLACE ECM
CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE MASS AIR FLOW METER
REPAIR OR REPLACE HARNESS OR CONNECTOR
CONFIRM GOOD CONNECTION TO ECM. IF OK, REPLACE ECM
REPLACE MASS AIR FLOW METER
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
DTC P0110 Intake Air Temperature Circuit
DTC P0112 Intake Air Temperature Circuit Low Input
DTC P0113 Intake Air Temperature Circuit High Input
DESCRIPTION
The intake air temperature sensor is built into the Mass Air Flow (MAF) meter and senses the intake air temperature.
A thermistor built into the sensor changes its resistance value according to the intake air temperature.
The lower the intake air temperature, the greater the thermistor resistance value. The higher the intake air temperature, the lower the thermistor resistance value (See Fig. 1).
The intake air temperature sensor is connected to the ECM.
The 5 V power source voltage in the ECM is applied to the intake air temperature sensor from terminal THA via resistor R.
Resistor R and the intake air temperature sensor are connected in series. When the resistance value of the intake air temperature sensor changes in accordance with changes in the intake air temperature, the potential at terminal THA also changes. Based on this signal, the ECM increases the fuel injection volume to improve driveability with a cold engine.
P0110| DTC Detection Drive Pattern | DTC Detection Condition | Trouble Area |
| Ignition switch ON for 0.5 seconds | Open or short in the intake air temperature (IAT) sensor for 0.5 seconds (1 trip detection logic). | Open or short in intake air temperature (IAT) sensor circuit
IAT sensor (built into mass air flow meter)
ECM
|
P0112| DTC Detection Drive Pattern | DTC Detection Condition | Trouble Area |
| Ignition switch ON for 0.5 seconds | Short in the IAT sensor for 0.5 seconds (1 trip detection logic). | Short in IAT sensor circuit
IAT sensor (built into mass air flow meter)
ECM
|
P0113| DTC Detection Drive Pattern | DTC Detection Condition | Trouble Area |
| Ignition switch ON for 0.5 seconds | Open in the IAT sensor for 0.5 seconds (1 trip detection logic). | Open in IAT sensor circuit
IAT sensor (built into mass air flow meter)
ECM
|
Related Data List| DTC No. | Data List |
| P0110 | Intake Air |
| P0112 |
| P0113 |
If DTC P0110, P0112 and/or P0113 is stored, the following symptoms may appear:
Misfire
Combustion noise
Black smoke
White smoke
Lack of power
When DTC P0110, P0112 or P0113 is stored, check the intake air temperature by entering the following menus: Powertrain / Engine / Data List / Intake Air.
Reference| Temperature Displayed | Malfunction |
| -40°C (-40°F) | Open circuit |
| 140°C (284°F) or higher | Short circuit |
WIRING DIAGRAM
INSPECTION PROCEDURE
- After replacing the ECM, the new ECM needs registration () and initialization ().
If DTCs relating to different systems are stored, and they share terminal E2 as their ground, check this ground circuit first.
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.
| 1.READ VALUE USING INTELLIGENT TESTER (INTAKE AIR TEMPERATURE) |
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON and turn the tester on.
Enter the following menus: Powertrain / Engine / Data List / Intake Air.
Read the value.
- OK:
- Same as actual intake air temperature.
Result| Result | Proceed to |
| -40°C (-40°F) | A |
| 140°C (284°F) or higher | B |
| OK (same as actual intake air temperature) | C |
If there is an open circuit, the tester indicates -40°C (-40°F).
If there is a short circuit, the tester indicates 140°C (284°F) or more.
| 2.READ VALUE USING INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS) |
Disconnect the mass air flow meter connector.
Connect terminals 4 (THA) and 5 (E2) of the mass air flow meter wire harness side connector.
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON and turn the tester on.
Enter the following menus: Powertrain / Engine / Data List / Intake Air.
Read the value.
- OK:
- 140°C (284°F) or higher
| 3.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) |
Disconnect the mass air flow meter connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance (Check for Open):
for LHD| Tester Connection | Condition | Specified Condition |
| C50-4 (THA) - C45-71 (THA) | Always | Below 1 Ω |
| C50-5 (E2) - C45-75 (E2) | Always | Below 1 Ω |
for RHD| Tester Connection | Condition | Specified Condition |
| C50-4 (THA) - C46-71 (THA) | Always | Below 1 Ω |
| C50-5 (E2) - C46-75 (E2) | Always | Below 1 Ω |
| 4.READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS) |
Disconnect the mass air flow meter connector.
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON and turn the tester on.
Enter the following menus: Powertrain / Engine / Data List / Intake Air.
| 5.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) |
Disconnect the mass air flow meter connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance (Check for Short):
for LHD| Tester Connection | Condition | Specified Condition |
| C50-4 (THA) or C45-71 (THA) - Body ground | Always | 10 kΩ or higher |
for RHD| Tester Connection | Condition | Specified Condition |
| C50-4 (THA) or C46-71 (THA) - Body ground | Always | 10 kΩ or higher |
| 7.CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE MASS AIR FLOW METER |
Replace the mass air flow meter ().
| 8.REPAIR OR REPLACE HARNESS OR CONNECTOR |
| 9.CONFIRM GOOD CONNECTION TO ECM. IF OK, REPLACE ECM |
| 10.REPLACE MASS AIR FLOW METER |
Replace the mass air flow meter ().
| 11.CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED |
Connect the intelligent tester to the DLC3.
Turn the ignition switch off.
Turn the ignition switch to ON for 1 second.
Enter the following menus: Powertrain / Engine / DTC.
Confirm that the DTC is not output again.
