Toyota Corolla

1992-1998 of release

Repair and operation of the car

Toyota Corolla
+ 1. Maintenance instruction
+ 2. Maintenance
+ 3. Engines
+ 4. Cooling systems, heating
+ 5. Fuel, exhaust systems
- 6. System of decrease in toxicity
   6.1. Specifications
   6.2. Electronic control system
   6.3. Electronic control unit
   + 6.4. System of onboard diagnostics
   - 6.5. Sensors of system of automatic control of the engine
      6.5.1. Sensor of temperature of cooling liquid
      6.5.2. Sensor of concentration of oxygen
      6.5.3. Sensor of an angle of rotation of a butterfly valve (TPS sensor)
      6.5.4. The sensor of absolute pressure on the soaking-up collector (MAR-sensor)
      6.5.5. The air temperature sensor on the soaking-up collector (IAT sensor)
      6.5.6. Temperature sensor of system of recirculation (EGR sensor)
      6.5.7. Car speed sensor (VSS sensor)
      6.5.8. Detonation sensor
      6.5.9. Sensor of an angle of rotation of the crankshaft
   6.6. System of catching of vapors of gasoline
   6.7. System of recirculation (EGR system)
   6.8. System of compulsory ventilation of a case (PCV system)
   6.9. Catalytic converter
+ 7. Transmissions
+ 8. Coupling and half shafts
+ 9. Brake system
+ 10. Suspension bracket and steering
+ 11. Body
+ 12. Electric equipment

6.5.5. The air temperature sensor on the soaking-up collector (IAT sensor)


Temperature characteristic of resistance of IAT-of the sensor

The air temperature sensor on the soaking-up collector is mounted in the case of the air filter. The sensor represents the resistor which value of resistance changes depending on air temperature coming to the engine.

At low temperatures value of resistance will be big (for example, at a temperature of 20 °C resistance of the sensor makes 2–3 kOhm) while at high temperatures resistance decreases (at 80 °C resistance of the sensor makes from 200 to 400 Ohms).

From the electronic control unit on the sensor of temperature voltage about 5 V (basic tension) moves. Tension on the sensor of temperature changes according to temperature of the arriving air. Tension signal arriving from the sensor on the control unit will be big at a low temperature and small at high. At failures in operation of the sensor in memory of the control unit the code 24 usually registers.


1. For check of IAT-of the sensor (1) open the bifurcate socket. Turn the ignition key in the situation ON, but do not start the engine.
2. Measure basic tension on contact of a yellow-black wire which has to be about 5 Century.
3. If basic tension differs from 5,0 B, hand over the control unit in a workshop of car service for check.
4. Measure resistance between contacts of the IAT sensor. At low air temperature resistance has to be big. Further, start the engine and translate in an operating mode idling. Warm up the engine.
5. Switch off ignition, disconnect the sensor and measure resistance between contacts. At high temperature of air resistance of the sensor has to be small. If change of resistance of the sensor differs from described, replace the sensor.