Description
The intake air temperature (iat) sensor, mounted on 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).
The iat sensor is powered by a 5 v supply from the tha terminal of the ecm, via resistor r.
Resistor r and the iat sensor are connected in series. When the resistance value of the iat sensor changes, according to changes in the iat, the voltage at terminal tha also varies. Based on this signal, the ecm increases the fuel injection volume when the engine is cold to improve driveability.
Monitor description
The ecm performs obd ii monitoring based on the values from the intake air temperature sensor. If there is no change of the sensor value within the normal range, the ecm will not be able to perform obd ii monitoring or will misdiagnose that there is a malfunction in the sensor. The ecm detects the stuck intake air temperature sensor value by performing monitoring after the ignition switch is turned off or the engine is started (short soak or long soak).
Monitor strategy
Typical enabling conditions
Typical malfunction thresholds
Wiring diagram
Refer to dtc p0110 (see page es-88).
Inspection procedure
Hint:
If any dtcs other than p0111 are output, troubleshoot those dtcs first.
Terminals of ecu
Check instrument panel junction block (main body ecu)
Measure the voltage of the connectors.
If the result is not as specified, the junction block
(main body ecu) may have a malfunction. ...
Basic inspection
When a malfunction is not confirmed by the dtc check,
troubleshooting should be carried out in all circuits
considered to be possible causes of the problem. In many
cases, by carrying out the basic engine check shown in the
following flowchart, the location of the problem can be found
quickly a ...
On-vehicle inspection
Check fan and generator v belt
Visually check the drive belt for excessive wear,
frayed cords, etc.
If any defect has been found, replace the drive belt.
Hint:
Cracks on the rib side of a drive belt are considered
acceptable.
If the drive belt has chunks missing from the r ...