194002528 - GENERAL REMARKS - GEARBOX (AUTOMATIC TRANSMISSION)

SPECIFICATIONS OF THE AISIN 55-50 SN AUTOMATIC TRANSMISSION

Compact five-speed transmission with front wheel drive

The 55-50 SN automatic transmission has a five speed gearbox with a new epicyclic gear train added to the four speed automatic gearbox, maintaining the same overall length and the same distance between the axles. It is also more compact and has a greater capacity compared with the transmission fitted on conventional vehicles.

ELECTRONIC CONTROL SYSTEM (CONTROL MODULE FOR TRANSMISSION AND ELECTRONIC COMPONENTS)

Specifications

In effect, in addition to the sophistication of the electronic control which governs the gear change strategies adapting to the style of the driver, there is the new TIP sequential alternative which allows the driver to use the vehicle in totally assisted conditions as found on conventional automatic transmissions and in manual gear change conditions with the TIP function where the intervention of the automatic function is limited to prevent incorrect or potentially damaging manoeuvres for the vehicle mechanics (the gearbox does not, for example, accept selections that would cause beyond rev conditions).The 5 speed Aisin type gearbox, with adaptive electronic control, with dual operating possibilities (Full Auto and Trip) is controlled by means of a double control grid for the gear lever positions.The electronic control mode adopted is the adaptive type, which means that the electronic management of the gear change is capable of analyzing the vehicle driving conditions and, after having compared them with the standard conditions memorized in its software, of selecting the operating programme (gear change law) that is best adapted to the current situation.The system manages the following three gear change laws:- Up hill: when driving uphill, the control unit compares the actual acceleration of the vehicle with the theoretical acceleration on a flat road, thereby determining the gradient of the road. It selects the change law and the most suitable ratio according to the gradient.- Down hill: when the control unit detects that the vehicle is accelerating with the throttle closed (descent) and is capable of estimating that by changing down a gear the vehicle will no longer be accelerating, it changes down a gear the first time the brake is operated.- Fast acceleration: depending on the speed with which the accelerator pedal is depressed, the control unit modifies the gear change and kick-down law.The electronic control unit manages the operation of the automatic transmission through connection with:the sensors/actuators fitted on the gearbox for acquiring the operating conditions and the operation of the clutches and brakes;- the injection/ignition control unit for the exchange of information relating to the engine;- the instrument panel for displaying the operating conditions.

ELECTRONIC COMPONENTS

Switch for start-up in neutral (nsw)

The switch for starting in neutral indicates the automatic transmission ratio, at a given time, to the starter motor, the reversing light and the automatic transmission control unit.The switch for starting in neutral can only start the engine in "P" and in "N" (to prevent reckless driving).The switch for starting in neutral ensures that the reversing light comes on when reverse gear is engaged.The switch for starting in neutral can also be used to control the gear change.The switch for starting in neutral transmits information, making use of the circuit for the starter motor and the vehicle side reversing light directly, without going from the automatic transmission control unit.

Gearbox solenoids n 1, 2, 3, 4, 5 (s1, s2, s3, s4, s5)

The five gearbox solenoids are fitted directly on the valve casing. The solenoids can be in the ON or OFF position, depending on the control signal arriving from the automatic transmission control unit. The combined action of the five solenoids (S1, S2, S3, S4, S5) makes it possible to change the gear ratios.

Input and output speed sensor (active sensors)

The output speed sensor detects the speed of the vehicle from the number of revs of the parking gear, whilst the input speed sensor detects the input speed for the automatic transmission from the number of revs of the drum C1: both then send a signal to the automatic transmission control unit.
Difference between the active sensor and the pulse sensorActive sensor specifications:this sensor has an integrated Hall circuit that manages the rectangular wave signal producing energy and transmitting the signal to the automatic transmission control unit exploiting the Hall effect. The automatic transmission control unit recognizes the signal in relation to the speed of the vehicle. The specifications of the output signal are fixed and do not therefore depend on the number of revs.- strong signal for noise- there may also be a low number of revs (10 rpm).Impulse sensor specifications:- as a result of the rotation of the gear, a sinusoidal wave with an induction electro-motive force is produced, in relation to the speed of the vehicle, which is then sent to the automatic transmission control unit. The control unit converts the wave signal into an impulse signal and recognizes it in relation to the speed of the vehicle. The specifications of the output signal depend on the number of revs.- the minimum number of revs that can be detected is 50 rpm.

Fluid temperature sensor

The oil temperature sensor is fitted directly on the valve casing which converts the temperature of the oil inside the automatic transmission into an electrical signal which is then sent to the automatic transmission control unit.

Linear pressure control solenoid (slt)

The linear pressure control solenoid controls the throttle valve by means of a signal arriving from the automatic transmission control unit in addition to the linear pressure of the clutch and the brake to reduce the shock from the gear change.Direct control

Lock up clutch control solenoid (slu)

The lock-up clutch control solenoid controls the linear pressure of the lock-clutch by means of the signal arriving from the automatic transmission control unit in addition to the hydraulic pressure of the lock-up clutch to reduce the shock from the gear change.Direct control:- Engine brake: Brake B3- Control of neutral (N): Brake B2.

Gearbox pressure control solenoid (sls)

The gearbox pressure control solenoid operates through a signal arriving from the automatic transmission control unit.Direct control:- control of 2nd, 3rd, 4th speeds and neutral (N): brake B1- control of 5th speed and reverse gear: clutch C2

Transmission conductor

The switch and sensor assembly, fitted on the automatic transmission, connects the switch for starting in neutral, the solenoids S1, S2, S3, S4, S5, SLT, SLU, the input speed sensor and the oil temperature sensor to three terminals.AUTOMATIC TRANSMISSION CONTROL UNIT PINOUTA1 - Key lock solenoid (gear control unit)A2 - Gearbox lock solenoid (gear control unit)A3 - I.E.A4 - I.E.A5 - OpenA6 - Left door open signalA7 - OpenA8 - Panel warning light signalA9 - Panel warning light signal (gear control unit)A10 - OpenA11 - Signal from diagnostic line (K line).A12 - A.B.S.A13 - A.B.S.A14 - Earth (-)A15 - OpenA16 - OpenA17 - OpenA18 - OpenA19 - OpenA20 - OpenB1 - Linear solenoid n° 5.B2 - Input speed sensor (+).B3 - Input speed sensor (+).B4 - Automatic transmission solenoid unit signalB5 - Throttle valve linear solenoid (+).B6 - Throttle linear solenoidB7 - Positive from battery.B8 - Throttle valve linear solenoid (-).B9 - Output speed sensor (-).B10 - Input speed sensor (-).B11 - Automatic transmission solenoid unit signalB12 - Automatic transmission solenoid unit signalB13 - Gear control unit signalB14 - Gear control unit signalB15 - Lock-up clutch linear solenoid (-).B16 - Gearbox solenoid n° 2.B17 - Gearbox solenoid n° 1.B18 - Power supplyB19 - Power supplyB20 - Throttle linear solenoidB21 - Oil temperature sensor (+).B22 - Oil temperature sensor (-).B23 - Automatic transmission solenoid unit signalB24 - Gear control unit signalB25 - Gearbox solenoid n° 4.B26 - Gearbox solenoid n° 3.B27 - Lock-up clutch linear solenoid (-).B28 - Earth (-).

Automatic transmission control unit control functions

Control of the gear change and the lock-up clutch.According to the gear change programmed, the control unit sends a signal to solenoids S1, S2, S3, S4 and S5, which are in the on/off position, to control the gear change in relation to the speed of the vehicle and the throttle valve opening.The 55-50SN version does not have different driving modes available for the driver to select. It is basically programmed for the "economy" mode, but the automatic gear change control unit can automatically change to different programmes depending on specific circumstances.Adaptive gearbox control by the driver (economy, medium, sports modes)The Economy mode is used in normal driving conditions after having turned the ignition on and the driver''s wishes are ascertained by using a logic that depends on the operation of the accelerator pedal. This makes it possible to change modes and move from Economy mode (low speed) to Regular mode (average speed) or Sports mode (high speed) according to the driver''s wishes.Uphill modes 1, 2When the control unit detects that the vehicle is driving uphill from the engine torque and deceleration conditions, it alters the gear change strategy in relation to the gradient of the incline and avoids overloading the automatic transmission with gear changes.Downill modeWhen the control unit detects that the vehicle is driving downhill, from the increased acceleration with the accelerator completely closed, it intervenes gently on the brake changing the gear change points at high speed.Fast control onThis control anticipates the desire of the driver to accelerate thanks to the operation of the accelerator changing down a gear only reviewing the gear change points.Fast control in off positionThis control anticipates the desire of the driver to decelerate thanks to the operation of the accelerator using the engine brake preventing a change to a higher gear.Brake assistance controlThis control anticipates the desire of the driver to decelerate thanks to the operation of the accelerator using the engine brake positively reviewing the gear change points at high speed.Gear control on bendsThis control evaluates the vehicle driving conditions round bends from the difference between the RL speed signal and the RR speed signal of the ABS, preventing a shift to higher gears, thereby ensuring the stability of the vehicle round bends.Wusp (warm up shift pattern)This mode warms up the engine, establishing the gear change points at a vehicle speed that is slightly higher that when the engine is cold.Acc (adaptative cruise control)By modifying the gear change points, this mode prevents acceleration and gear changes.Excessive fluid temperature controlWhen the temperature of the oil is too high, the control unit automatically modifies the gear change arrangements. As a result, driveability is improved in low gears. In addition, the temperature of the oil and the water when decreasing, activate the lock-up clutch.Esp (electronic stability program)In the case of a slippery road, this mode maintains the gear engaged requiring a maintenance signal for the gear from the VDC computer and ensuring the manoeuvrability of the vehicle preventing first gear from being engaged.Low load control µThis mode improves traction performance during set-off in third when leaving roads with low µ (grip coefficient) or with potholes.

Tip gear shift control (manual mode)

The driver can select the gear they prefer taking advantage of sports driving simply by moving the gear lever from "D" using the MAN+ or MAN- button. The control of the lock-up clutch is activated automatically. The control of the gear change is activated again moving from manual driving to "D".Below is a list of the TIP mode active controls.Authorisation to shift to higher gearsThis control is activated provided that the vehicle speed exceeds the figures shown in the table below. The vehicle can start in second or in third even from stationary.
Throttle valve opening0%20%More than 30%
From 1st to 2ndMore than 0 km/hMore than 0 km/hMore than 16 km/h
From 2nd to 3rdMore than 0 km/hMore than 0 km/hMore than 28 km/h
From 3rd to 4thMore than 33 km/hMore than 33 km/hMore than 54 km/h
From 4th to 5thMore than 38 km/hMore than 38 km/hMore than 71 km/h
Authorisation to shift to lower gearsThis control is activated to prevent the engine going outside of the rev range, provided that the speed of the vehicle does not exceed the figures given in the table below.
From 2nd to 1stLess than 59 km/h
From 3rd to 2ndLess than 104 km/h
From 4th to 3rdLess than 160 km/h
From 5th to 4thLess than 236 km/h
Automatic transfer to lower gearsThis control is activated automatically according to the speeds shown in the table below.
From 2nd to 1stLess than 2 km/h
... DATA ERROR - CROPPED TEXT | Ошибка данных - Текст обрезан ...