Subaru Forester

1997-2005 of release

Repair and operation of the car



Subaru Forester
+ Subaru Forester cars
+ Maintenance instruction
+ Routine maintenance
+ Engine
+ Cooling systems, heating
+ Power supply system and release
+ Engine electric equipment
+ Control systems of the engine
- Gear shifting box
   + 5-staged manual box of gear shifting (MBGS)
   - 4-staged automatic transmission (AT)
      General information and principle of functioning
      Failure diagnostics of AT - the general information
      Adjustments of AT
      Electrohydraulic control system of AT, - the general information, purpose of basic elements
      System of self-diagnostics, reading of codes of malfunctions
      Removal and AT installation
+ Coupling, transmission line
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment


Electrohydraulic control system of AT, - the general information, purpose of basic elements

Various sensors and switches, electronic control unit (TCM), valvate assembly and set of electromagnetic switches are a part of an electrohydraulic control system of AT.

The system exercises control of gear shifting of AT, blocking of the hydrotransformer, the coupling of providing the mode of braking with the engine, pressure in the main highway, the coupling of control of the back drive. In other words, system, analyzing information arriving from sensors, monitors changes of parameters of the movement and issues the corresponding commands for six electromagnetic valves: 1, 2, 3, A, V and S.

The sensor of provision of a butterfly valve (TPS) serves for definition of extent of opening of a butterfly valve. On the basis of information of TCM arriving from TPS defines the moments of gear shifting and blocking of the hydrotransformer, and also forms pressure in the main highway.

The sensor of speed of the movement of the car No. 1 (VSS 1) is installed in a case of AT and is used when determining speed of the movement of the vehicle. On the basis of the analysis of information of TCM arriving from the sensor defines the moments of gear shifting and blocking of the hydrotransformer, and also forms pressure in the main highway. AN all-wheel drive models a drum of the coupling of the back drive by means of the driveshaft is connected directly to back wheels therefore VSS 1 determines the speed of rotation of back wheels.


The sensor of speed of VSS 2 is used for control of the coupling of the drive of back wheels, besides, duplicates the VSS 1 functions on a case of an exit of the last out of operation.

The RPM meter of the engine serves for determination of frequency of rotation of the engine. The signals given by the sensor are used at management of blocking of the hydrotransformer.

The sensor of position of the lever of the choice of ranges of AT/permission of start allows TCM to define position of the lever of the choice of ranges of transmission. On the basis of the analysis of information of TCM arriving from the sensor carries out formation of pressure in the main highway. Besides, the sensor ensures safety of start of the engine, forbidding performance of the last in other than "N" and "Р" provisions of transmission due to disconnection of a chain of a starter.


The sensor switch of full closing of a butterfly valve serves for definition of the mode of full closing of a butterfly valve and TCM at management of functioning of the blocking coupling of the hydrotransformer and formation of pressure in the main highway is used.

The switch of a tempostat (at the corresponding complete set of the car) is intended for inclusion/switching off of a control system of speed if that is included in the vehicle package.


The sensor switch of temperature of ATF allows TCM to trace continuously temperature of transmission liquid, using the arriving information when blocking the hydrotransformer. The sensor is a thermistor resistance of which in inverse proportion to ATF temperature.

Output characteristic of the sensor.
1  —  ATF temperature Sensor


The manual switch allows to forbid inclusion of the 4th transfer at the movement on off road terrain.

The switch of installation of economy mode of the movement is used on appropriately equipped models for shutdown of the back drive.

The sensor switch of the kickdown mode notifies TCM on full squeezing of the accelerator pedal and need of transition to a low gear for the purpose of short-term increase in return of the engine, for example when overtaking.

Electromagnetic valves of switching of AT


1  —  the Electromagnetic valve A of adjustment of pressure in the main highway
2  —  the Electromagnetic valve 2
3  —  the Electromagnetic valve 1
4  —  the Electromagnetic valve 3 managements of the braking mode of the engine
5  —  the Electromagnetic valve In managements of blocking of the hydrotransformer

 


Electromagnetic valves of switching. Electromagnetic valves of switching 1 and 2 are installed in valvate assembly and, depending on the character arriving on them from the module of management of a signal can borrow one or the other the fixed provisions: It is included (ON) or switched off (OFF). The combination of conditions of these electromagnetic valves defines the transfer chosen in a box. The electromagnetic valve 3 serves for control of the braking coupling of the engine, also is a part of valvate assembly) and can be in one of two fixed states (ON or OFF). The electromagnetic valve A is used at management of pressure in the main highway, is installed in valvate assembly, is the managing director оп to the relation to valves of modification and adjustment of pressure by means of this TCM valve forms pressure in the main highway which is most effectively answering to the current requests of the power unit. The electromagnetic valve B allows TCM to exercise control of functioning of the blocking coupling of the hydrotransformer.

Electromagnetic valve of management of functioning of the coupling of turning on of the back drive


1  —  the Electromagnetic valve From management of functioning of the coupling of turning on of the back drive

 


The electromagnetic valve C is installed in valvate assembly and, on appropriately equipped models, TCM at management of functioning of the coupling of turning on of the back drive is used. The means of this TCM valve exercise control of functioning of the distributive valve forming pressure in the booster of the coupling of the back drive.

TCM. On the basis of the analysis of the signals arriving from various sensors the control unit of transmission defines traffic conditions of the vehicle and develops the corresponding commands for management of switchings of transmission.

Indicator lamp of the mode of functioning of transmission. The control system of AT is equipped with function of the automatic choice of one of two modes of the movement: the normal mode used under usual service conditions and the mode of the increased selection of engine capacity. The last mode is used at the movement uphill, and also joins at sharp squeezing of the accelerator pedal. The modes of functioning of the indicator are tabulated given below.

Position of the lever of the selector of range

Switching from the normal mode to the mode of the increased selection of power

Mode of functioning of the indicator

"D", "3", "2" Is chosen automatically according to the nature of use of the accelerator pedal Normal: VYKL (OFF)
The increased selection of power: VKL (ON)