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Toyota RAV4 Service Manual: Intake air temperature sensor gradient too high

Toyota RAV4 Service Manual / 2Az-fe engine mechanical / Sfi system / Diagnostic trouble code chart / Intake air temperature sensor gradient too high

Toyota RAV4. Intake air temperature sensor gradient too high


Description

Toyota RAV4. 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.

Toyota RAV4. Intake air temperature sensor gradient too high


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

Toyota RAV4. Monitor strategy


Typical enabling conditions

Toyota RAV4. Typical enabling conditions


Typical malfunction thresholds

Toyota RAV4. Typical malfunction thresholds


Wiring diagram

Refer to dtc p0110 (see page es-88).

Inspection procedure

  1. Check any other dtcs output (in addition to dtc p0111)

  1. Connect the intelligent tester to the dlc3.
  2. Turn the ignition switch on.
  3. Turn the tester on.
  4. Enter the following menus: diagnosis / enhanced obd ii / dtc info / current codes.
  5. Read dtcs.

Toyota RAV4. Check any other dtcs output (in addition to dtc p0111)


Hint:

If any dtcs other than p0111 are output, troubleshoot those dtcs first.



Intake air temperature circuit malfunction
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 ac ...

Engine coolant temperature circuit
Description A thermistor, whose resistance value varies according to the ect, is built into the engine coolant temperature (ect) sensor. The structure of the sensor and its connection to th ...

Other materials:

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
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On-vehicle inspection
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