Subaru Legacy/Outback

1999-2003 of release

Repair and operation of the car



Subaru of Legasi, Autbek
+ Cars Subaru Legacy, Outback
+ Operation manual
+ Routine maintenance
+ Engine
+ Cooling systems, heating
+ Power supply system and release
+ Electric equipment of the engine
+ Manual box and differential
- Automatic transmission
   Specifications
   Electrohydraulic control system - the general information, purpose of basic elements
   System of self-diagnostics - the general information and the principles of functioning
   Diagnostics of the general condition of AT
   Problem diagnostics of AT
   Removal and installation of transmission assembly
   Replacement of elements of a suspension bracket of transmission assembly
   Replacement of an epiploon of a casing of lengthening of AT
   Check of a state, adjustment and replacement of the sensor switch of permission of start
   Removal and installation of the forward sensor of the speed (VSS)
   Removal and installation of the back sensor of the speed (VSS)
   Removal and installation of the sensor of turns of the turbine of the hydrotransformer
   Removal, service and installation of valvate assembly
   Replacement of electromagnetic valves of switching, executive electromagnetic valves and sensor of temperature of ATF
   Replacement of the ATF filter
   Removal and installation of the module of management of transmission (TCM)
   Removal, installation and check of a condition of lines of a path of cooling of ATF
   Removal, service and installation of components of the lever of the AT selector
   Removal, installation, check of a state and adjustment of a driving cable of the AT selector
+ Coupling
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment




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

The electronic control system of all all-wheel drive (AWD) Subaru models is developed on the basis of a control system of front-wheel (FWD) models. The hydraulic part of a control system in addition includes the electromagnetic valve and the coupling of control of the drive of back wheels. On the basis of the analysis of the data of TCM arriving from various information sensors determines the optimum size of the torque transferred to back wheels of the car and realizes it by means of the electromagnetic valve due to management of pressure in the booster of the coupling of management of the back drive. Schemes of hydraulic connections of transmissions of both types on the example of a choice of the 4th transfer in the D mode with the switched-off blocking of the hydrotransformer are submitted on illustrations.

Function chart of a hydraulic contour of management of MPT AT on the example of a choice of the 4th transfer in the D mode with the disconnected blocking of the hydrotransformer

 


Function chart of a hydraulic contour of management of MPT AT on the example of a choice of the 4th transfer in the D mode with the disconnected blocking of the hydrotransformer

 


Function chart of a hydraulic contour of management of VTD AT on the example of a choice of the 4th transfer in the D mode with the disconnected blocking of the hydrotransformer

 


Function chart of a hydraulic contour of management of VTD AT on the example of a choice of the 4th transfer in the D mode with the disconnected blocking of the hydrotransformer

 


The electronic control system precisely sets the modes of functioning of the operating coupling of the back drive that is especially effective at operation of the car in severe road conditions at the movement at small speeds when smoothness of change of the traction effort developed by driving wheels is of particular importance.

The electrohydraulic control system consists of a set of information sensors / datchikov-vyklyuchateley, TCM and hydraulic knots including electromagnetic valves. The system provides management of such AT functions as gear shifting (including correction of the moments of switching), blocking of the hydrotransformer, adjustment of pressure to lines, a choice of an optimum operating mode (Base/Power), and also control of functioning of the distributing coupling (MPT model) / the multidisk coupling of restriction of slipping of interaxal differential (VTD model). On the basis of the analysis of parameters of entrance signals of TCM defines a working condition of the car and exercises control of functioning of eight electromagnetic managing directors of valves (valves of switchings 1 and 2, distributive electromagnetic valves of coupling of the lowering transfers and a brake of 2-4 transfers, executive valves of pressure in the line, blocking of the hydrotransformer, the distributing device and a brake of 2-4 transfers).

In comparison with RKPP automatic transmission promotes increase of the general controllability of the car that first of all is reflected in comfort of the movement. The function chart of an electrohydraulic control system of AT is presented on an illustration.

 


Signals of input-output of TCM

Entrance signals

The signal of the sensor of provision of a butterfly valve (TPS) is used for definition of a point of switching, pressure in the line and the movement speed depending on load of the engine at which blocking of the hydrotransformer has to be made.

The signal of the forward sensor of speed of the car (VSS) (is located on AT case) is used at management of gear shifting, blocking of the hydrotransformer, pressure in the line and operation of the distributing coupling.

The signal of back VSS (is located on the lengthening case) is used at management of functioning of the distributing coupling, and also as a feedback signal at refusal of VSS.

The signal of turns of the engine is used at management of blocking of the hydrotransformer for a guarantee of smoothness of switchings.

The signal of the sensor switch of permission of start is used when determining transfers and pressure in the line in each of provisions of the lever of the selector.

The signal of the sensor switch of temperature of ATF is used for suppression of blocking of the hydrotransformer, an otpuskaniye of OD and determination of temperature of transmission liquid.

The switch of the forward drive (MPT model) is used for imitation of the front-wheel mode at bench checks of the car (similar function the crossing point established in the holder of the corresponding safety lock carries out).

The signal of ABS is used by optimization of management of functioning of anti-blocking system. The essence of optimization consists in adjustment of distribution of a torque between lobbies and back wheels of the car for the purpose of suppression of action of braking by the engine and decrease in dependence of functioning of one wheels from others.

The signal of a tempostat warns TCM about activation of a control system of speed and is used for expansion of working range of the 4th transfer.

The sensor of turns of the turbine of the hydrotransformer informs TCM on the frequency of rotation of an entrance shaft. Whether between this parameter and speed of the movement of the car the module of management determines by a ratio there is a need in transmission switchings.

The signal of shutdown of control of distribution of a torque is given on the engine management TCM module for the purpose of a suspension of management of distribution of a torque.

Switch of the HOLD mode. In the position of this switch closed (ON) the car starts from the 2nd transfer (at a choice of range of "D", "3" or "2") that facilitates procedure of a start of motion at a slippery paving.

The switch of the mode of the increased power (POWER). In the position of this TCM switch closed (ON) carries out gear shifting according to installations of the mode of the increased power (POWER).

The signal of the sensor switch of activation of the kickdown mode is used for the warning of TCM of full opening of a butterfly valve and need of switching of transmission on a low gear.

Braking sensor switch. If the signal of this sensor switch is generated at the movement under a bias, TCM carries out transition of transmission to a low gear for the purpose of braking activation by the engine.

The signal of TCS (VTD model) is used by optimization of management of functioning of antiprobuksovochny system (TCS). The essence of optimization consists in adjustment of distribution of a torque between lobbies and back wheels of the car for the purpose of suppression of action of braking by the engine and decrease in dependence of functioning of one wheels from others.

The signal of VDC (VTD model) is used by optimization of management of functioning of system of dynamic stabilization (VDC). The essence of optimization consists in adjustment of distribution of a torque between lobbies and back wheels of the car for the purpose of suppression of action of braking by the engine and decrease in dependence of functioning of one wheels from others.

The signal of the sensor of an angle of rotation of a steering wheel (VTD model) is used for monitoring of behavior of the car at development of signals of management of a torque transmission on back wheels.

Signals of sensors of the taking-away moment / cross accelerations (VTD model) are used for monitoring of behavior of the car at development of signals of management of a torque transmission on back wheels.

Output signals

Signals of electromagnetic valves of inclusion 1 and 2 control a step of switching of transfer by inclusion/switching off of the corresponding electromagnetic valve.

The executive electromagnetic valve of pressure in the line regulates pressure in the line according to traffic conditions.

The executive electromagnetic valve of blocking of the hydrotransformer regulates the hydraulic pressure of the blocking coupling for management of it in 3 modes (open, smooth, blocking).

The executive electromagnetic valve of control of the drive of back wheels regulates hydraulic pressure on the distributing coupling for the purpose of control of loading of an output shaft.

The control lamp of temperature of ATF lights up at excess by temperature of transmission liquid of maximum permissible value.

The executive electromagnetic valve of a brake 2-4 regulates the working pressure of brake assembly of 2-4 transfers for the purpose of ensuring absence of stress of switching.

The distributive electromagnetic valve of a brake 2-4 controls giving/shutdown of pressure upon the distributive valve B of brake assembly of 2-4 transfers at management of the moment of shutdown of a brake.

The distributive electromagnetic valve of coupling of the lowering transfers controls giving/shutdown of pressure upon the distributive valve In couplings of the lowering transfers at management of coupling functioning, and also exercises control of giving/shutdown of pressure upon the corresponding valve for a ban of inclusion of transfer of a backing.

Signals of management of a torque 1 and 2 provide decrease in a torque of the engine at a choice of range and change of transfer.

The light indicator of inclusion of the mode of the increased power (POWER) warns about switchings of transmission between the Base and Power modes, - the indicator shines at activation of the POWER mode. Besides, this indicator can be used for a conclusion of diagnostic codes of malfunctions of system of onboard self-diagnostics of diagnostics.

The light indicator of the HOLD mode warns about switchings of transmission between the Base and Hold modes, - the indicator shines at activation of the HOLD mode.

Principles of functioning of a control system and its separate elements


Control system


MPT AT

The control system of AT can be broken into two subsystems: subsystem of management of functioning of transmission and subsystem of management of functioning of the distributing coupling.

Subsystem of management of functioning of transmission

The subsystem exercises control of the AT following functions: gear shifting, blocking of the hydrotransformer, adjustment of pressure to lines and a choice of the moments of gear shifting.

Within management of gear shifting the following functions are carried out:

a) A choice of the moments of the raising or lowering switching according to installations of the mode of functioning of transmission (Base or Power) taking into account the current provision of a butterfly valve and speed of the movement of the car;
b) Fixing of AT on the 3rd transfer at receipt of an entrance signal of ABS;
c) A switching ban on the 4th transfer at insufficient warming up of ATF;
d) Blocking of the 1st transfer in the ranges of "D", "3" or "2" AT at activation of the HOLD mode from the corresponding switch.

Within management of blocking of the hydrotransformer control actually blocking inclusions/switching off, and also control of smoothness of its inclusion is exercised:

a) According to basic uka blocking is included constantly at the movement on the 4th transfer in the range of the "D" transmission whereas dynamic management of a condition of the hydrotransformer (blocking inclusion/switching off) is made on all other transfers in any ranges of AT depending on the current provision of a butterfly valve and speed of the movement of the car. The exception is made only by the gear shifting moments when blocking is disconnected by default;
b) Control of smoothness of activation of blocking is exercised every time at its inclusion.

Control of pressure in the line is exercised constantly:

a) In usual conditions pressure is regulated according to the provision of a butterfly valve, speed of the car and signals of a choice of ranges;
b) At the transition moments from transfer on transfer pressure in the line is regulated for the purpose of ensuring absence of stress of switching;
c) At a start of motion pressure in the line forcibly goes down for the purpose of restriction of increase of loads of the engine.

Within management of the moments of gear shifting the following functions are carried out:

a) Adjustment of a step of switching by management of operation of the electromagnetic valve;
b) Control of blocking of the hydrotransformer in way a temporary otpuskaniye of the blocking coupling at the gear shifting moments;
c) Optimization of pressure in the line for the purpose of ensuring absence of stress of switchings of transmission.

Subsystem of management of functioning of the distributing coupling

The number of the tasks which are carried out by this subsystem includes the following:

a) Adjustment of pressure given on the coupling of control of the drive of back wheels according to the current provision of a butterfly valve and speed of the movement of the car;
b) Increase of the operating pressure upon the coupling at inclusion of range of "1" AT;
c) Installation of the operating pressure upon the level corresponding to the movement mode on the 1st transfer (see the previous point) at identification of the moment of the beginning of pro-slipping of wheels, - this function is disconnected at the movement with a speed over 60 km/h, and also at full closing of a butterfly valve;
d) Decrease in the managing director of pressure given on the coupling during commission of turns;
e) Installation of pressure upon the set level at receipt of entrance signals of ABS.

VTD AT

The control system of AT can be broken into two subsystems: subsystem of management of functioning of transmission and subsystem of management of functioning of the multidisk coupling of interaxal differential of limited sliding (LSD).

Subsystem of management of functioning of transmission

The tasks which are carried out by this subsystem are similar described above for transmissions of MPT type.

Subsystem of management of functioning of the multidisk coupling of interaxal differential of limited sliding (LSD)

The number of the tasks which are carried out by this subsystem includes the following:

a) Adjustment of the operating pressure upon the LSD coupling according to an entrance torque, and traffic conditions;
b) Adjustment of the operating pressure during a start of motion it is proportional to a corner of opening of a butterfly valve;
c) Decrease in the operating pressure upon the coupling during commission of turns when the relation of speeds of rotation of lobbies and back wheels appears less than some value established for the current high-speed mode;
d) Decrease in the operating pressure upon the coupling at identification of the moment of the beginning of pro-slipping of lobbies or back wheels;
e) Installation of pressure upon the set level at receipt of entrance signals of ABS.
f) Decrease in the operating pressure upon the coupling at short circuit (ON) of the sensor switch of braking and full closing of a butterfly valve (basic control);
g) Increase of the operating pressure at activation of the 1 mode of AT for the purpose of improvement of controllability of the car.

Module of management of transmission

TCM is "brain" of a control system of transmission which on the basis of the analysis of the data arriving from various information sensors / datchikov-vyklyuchateley ("the nervous terminations"), determines the current working parameters of the movement and gives out the corresponding commands for the operating electromagnetic valves ("muscles"). The similar mechanism allows to exercise control of gear shifting, blocking of the hydrotransformer and adjustment of pressure given on the distributing coupling (MPT models) / the multidisk LSD coupling (VTD models) according to the chosen working uka, road conditions and the current requirements of the engine.

The light indicator of inclusion of the mode of the increased power (POWER)

As it was already mentioned above, the number of the other functions which are carried out by TCM includes function of an automatic choice of one of two managing directors of the modes: "Basic" (Base) or Increased Return Capacities mode (Power). The choice carries out according to a manner of driving of the driver which TCM defines proceeding nature of management of a gas pedal. Usually basic mode is used at the movement on the equal road while the most typical conditions of activation of the Power mode are sharp accelerations and the movement uphill. The light Power indicator installed on the dashboard lights up at short circuit of the corresponding sensor switch during activation of the mode of the increased power at the movement in AT D, 3 or 2 modes.

Sensor of provision of a butterfly valve (TPS)

TPS gives out the electric signals corresponding to provisions an angle of rotation of a butterfly valve. On the basis of the analysis of the data of TCM arriving from the sensor defines extent of opening of a butterfly valve and speed of squeezing by the driver of a pedal of gas.

Sensors of the speed (VSS)

Location of VSS sensors is shown on an illustration.

1 — Back VSS
2 — Forward VSS


Back VSS

Back VSS (the sensor of turns of an output shaft) is established outside on the case of lengthening of AT.

On transmissions the MPT sensor registers the frequency of rotation of back wheels on the peripheral speed of elements of the forming surface of a drum of the distributing coupling and gives out on TCM the corresponding signal of a sinusoidal form (on 30 impulses on one turn of an output shaft).

On transmissions the VTD sensor traces the peripheral speed of elements of the forming surface of directly output shaft, giving out on TCM of 22 sinusoidal impulses on one turn of a shaft.

Forward VSS

Forward VSS (the sensor of turns of an output shaft) is established outside on a transmission case. The sensor gives out the alarm tension of a sinusoidal form (on 16 impulses on one turn) corresponding to the frequency of rotation of forward wheels of the car which the module of management will transform to 4-pulse signals which are given out on ECM and a combination of devices on TCM.

ATF temperature sensor

The sensor is built in valvate assembly of transmission, represents a thermistor which resistance changes in inverse proportion to change of temperature and serves for determination of temperature of transmission liquid. Location of the sensor in valvate assembly and its output characteristic are presented on an illustration.

1 — ATF temperature Sensor


Sensor of turns of the turbine of the hydrotransformer

The sensor of turns of the turbine of the hydrotransformer (the sensor of turns of an output shaft) is installed outside on a case of transmission and serves for determination of frequency of rotation of the turbine of the hydrotransformer on the peripheral speed of elements of the forming surface of a drum of the coupling of coupling of the raising transfer connected to an entrance shaft. The sensor gives out on TCM a signal of a sinusoidal form (32 impulses on one turn of a shaft) on the basis of which results of processing the module of management defines a ratio of turns of an entrance shaft and speed of the movement of the car and resolves an issue of need of switching of transfer.


Sensor switch of permission of start (P/N)

This sensor switch is installed on the right side of a case of transmission, copes from the lever of the AT selector and provides a safety guarantee at implementation of start of the engine. sensor switch

When the lever of the selector is in the situation P or N, the electric chain of the sensor switch of permission of start is closed and a starter is ready to an engine provorachivaniye.

In all other provisions of the lever the sensor switch provides disconnection of a chain of a starter, preventing thereby possibility of implementation of start of the engine. At inclusion of a reverse gear ("R") the P/N sensor switch provides operation of fires of a backing.

Besides, the sensor switch of permission of start informs TCM on position of the lever of the selector.

The ID card of plugs of the sensor switch of permission of start is given in an illustration.


Valvate assembly

The scheme of an arrangement of components of valvate assembly is submitted on an illustration.

Arrangement of electromagnetic valves of switchings 1 and 2 in valvate assembly of AT

1 — the Electromagnetic valve of switching 2
2 — the Electromagnetic valve of switching 1
3 — the Electromagnetic valve of coupling of the lowering transfers
4 — the Distributive electromagnetic valve of a brake 2-4

5 — the Executive electromagnetic valve of pressure in the line
6 — the Executive electromagnetic valve of blocking of the hydrotransformer
7 — Executive electromagnetic the valve of a brake 2-4


Electromagnetic valves of switchings 1 and 2

These valves are a part of valvate assembly of an electrohydraulic control system of AT. Valves are activated at the command of TCM and carry out the corresponding switchings of transmission.

The distributive electromagnetic valve of coupling of the lowering transfers

This electromagnetic valve is built also in valvate assembly, works at the command of TCM and operates functioning In - the valve of coupling of the lowering transfers and the valve of a ban of inclusion of a reverse gear.

Distributive electromagnetic valve of a brake 2-4


Location of the valve in valvate assembly is shown on an illustration. The valve is activated at the command of TCM and provides absence of stress of switchings of transmission due to management of functioning of the V-valve of brake assembly 2-4.

The executive electromagnetic valve of pressure in the line


The valve also is a part of valvate assembly, functions under control of TCM and provides adjustment of pressure in the line according to the current traffic conditions by management of functioning of the valve modulator of pressure and the control A-valve of the accumulator for optimization of pressure in the line to the level suitable for service conditions.

Executive electromagnetic valve of blocking of the hydrotransformer


By means of this TCM valve operates functioning of the corresponding control valve providing smoothness of inclusion/switching off of blocking of the hydrotransformer due to management.

Executive electromagnetic valve of a brake 2-4


Working under control TCM, this valve provides absence of stress of switchings due to management of modulations of working pressure of brake assembly 2-4.

Executive electromagnetic valve of the distributing device

This valve is a part of the valvate assembly of control of the distributing mechanism which is located in back part of a case of transmission. By means of this TCM valve provides management of pressure given on the distributing coupling / the operating valve of multidisk coupling of LSD.