Toyota Corolla

1992-1998 of release

Repair and car operation

Toyota Corolla
+ 1. Maintenance instruction
+ 2. Maintenance
+ 3. Engines
+ 4. Systems of cooling, 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
   6.6. Catching system паров gasoline
   6.7. System retsirkulyatsiya (EGR system)
   6.8. System of compulsory ventilation of a case (PCV system)
   6.9. Catalytic converter
+ 7. Transmissions
+ 8. Coupling and semi-axes
+ 9. Brake system
+ 10. Suspension bracket and steering
+ 11. Body
+ 12. Electric equipment

6.2. Electronic control system


Place of installation of devices of control systems of the engine and decrease in toxicity

1. Ignition key
2. Relay of the fuel pump
3. Control unit engine
4. Socket of 1 data link
5. Control air valve of idling
6. Auxiliary sensor of concentration of oxygen (1 *)
7. The air temperature sensor on a soaking-up collector
8. Sensor of speed of the car
9. Item Park/Neutral switch (2 *)
10. Sensor of concentration of oxygen
11. Main sensor of concentration of oxygen (2 *)
12. The sensor of temperature of cooling liquid
13. Integrated block of electronic ignition of Toyota firm (IIA block)
14. Nozzle
15. Sensor of an angle of rotation of a butterfly valve (TPS sensor)
16. The sensor of absolute pressure on a soaking-up collector (MAP sensor)
17. Amplifier of central air
18. The electropneumovalve of compensation of turns of idling at turning on of the conditioner
19. Guard of devices
20. Fuel pump

1* only for cars of the State of California (USA)
2* only for cars with automatic transmission

Management of cистемой of injection of fuel is carried out by the onboard microcomputer called by the electronic control unit (ECM).

In the electronic control unit information from the various sensors tracing such working parameters of the engine as volume and temperature of sucked-in air, temperature of cooling liquid, engine turns, a mode of dispersal or braking by the engine, concentration of oxygen in exhaust gases etc. arrives. Signals are used by the electronic control unit for the correct determination of duration of injection of fuel. On the basis of the data received from sensors, the control unit defines optimum duration of injection of fuel.

The system is similar to the central nervous system of the person. Sensors (the nervous terminations) constantly transmit signals to the electronic control unit (in system "brain") which processes the obtained data, and, in case of need, sends team for change of working parameters of the engine (to a body).

Let's give an example functioning of a part of this system.

The sensor of concentration of the oxygen, screwed in a final collector, constantly traces the content of oxygen in exhaust gases. If percentage of oxygen in exhaust gases is higher than norm, the electric signal goes to the electronic control unit. The electronic control unit receives this information, processes it and then gives team in a control system of the fuel injection, forcing to change composition of gas mixture. On the working engine it occurs in fractions of a second and proceeds continuously. The end result is maintenance of composition of gas mixture at the set level, irrespective of driving conditions.

In default the sensor the reserve scheme simulating the faulty sensor which provides preservation of road performance of the car before malfunction elimination joins.


Considered cars are equipped with safety cushions. At any time at the connected battery, the pillow (which has a rigid design) can be developed to (be inflated). To exclude casual operation of a pillow (and possible traumas) at performance of any works near safety cushion details, turn the ignition key in the situation Lock and disconnect the battery from weight. After shutdown of the battery wait two minutes (necessary for a full discharge of the reserve condenser). More detailed description is provided in subsection 12.24.

Before a battery detachment from weight be convinced that to you the code of a raskodirovka of a radio tape recorder (if the last is equipped with the blocking device in case of plunder) is known.

Observe the following rules:
       – before a detachment of any electric sockets always disconnect a food of onboard system of the car by ignition key turn in the situation OFF, or having disconnected the battery from weight;
       – at installation of the storage battery observe polarity of connection of cables;
       – it is forbidden to subject to strong blows of a detail of system of electronic injection of fuel and system of decrease in toxicity during removal or installation;
       – be accurate during search of malfunctions. Even short-term short circuit of conclusions of sockets can lead to the wrong results of check or to failure of one of numerous transistor schemes;
       – it is forbidden to repair independently the control unit, or to open a cover of the case of the electronic control unit;
       – do not allow water hit on system sensors at their survey during rainy weather. At a sink of a compartment of the engine do not spray water on sensors and control system sockets.