electronic control system

8/3/2019 Electronic Control System

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Electronic Control SystemSignals

Main Points

The electronic control system used in the new generation auto transaxleis far superior to the previous systems .This system is able to adopt a variable shift pattern for smooth and

problem free shifting.A solenoid valve is applied to each clutches and brakes and is

independently controlled. Feedback control and correction control isperformed in all gears as well as utilization of mutual control system toincrease shift feeling.The torque converter damper clutch uses a partial lock up and full lock-upsystem.An additional control method called the INVECS-II system (neuralnetwork) is adopted to increase shift feeling.


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System Block Diagram

INVECS-IIIn addition to the variable shift pattern control, the INVECS-II system with neural

network is also adopted for the first time in KMC. INVECS-II uses information fromvarious inputs and feedback adaptation and selects the best appropriate gear position

and shift timing under all possible driving conditions.Optimal control for all driving condition

This function makes TCM decide optimal gear range under all drivingcondition. The optimal operation of the manual shift lever by severaldriver's and various driving condition is pre-set in the TCM. On the basisof mapping data, TCM decides the driving condition from throttle opening,vehicle speed and brake signal. And then TCM controls the gear positionoptimally. Optimal gear position is achieved under various driving

condition by INVECS-II logic.


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Neural Network Control

In order to perform the best shift feeling, the computer must processcomplicated data. But "FUZZY THEORY " is impossible to execute it.Therefore, the neural network control enable the A/T the optimal shift.The neural network control is designed to approach a man' brain.This system processes the relationship between data, decides andcontrols the system.


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Adaptive control

As it is possible to execute optimal gear position by optimal control,drivers want to drive the vehicle as their taste and habit.There is a adaptive control. It controls the driving condition which is wanted by driverunder driver's tendency.

The TCM receives throttle opening, vehicle speed and brake signal. And then itrevises the gear position according to driving condition by driver's mind.

Fuzzy ControlThe computer distinguishes "0" or"1", that is "True" or "False" but it doesn'tdistinguish obscure concept. The FUZZY theory gets obscure concept as well as"True" or "False".

Down Hill Down Shift FunctionINVECS-II down shifts to obtain the best possible engine brake whendriving down hill.

4th gear 3rd gear (vehicle speed


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Down Hill Down Shift Adaptive Control Function

INVECS-II does not function under the following conditions.- ATF temperature below 40.- When standard pattern is not used.

? Inhibitor switch: P, R, N, L? Under the Hold mode


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? Extremely low temperature mode? Lower emission shift pattern? ATF control variable shift pattern

- During fail safe mode (3rd gear hold)- In case of prohibition of Intelligent shift

? TPS faulty (Short: P1702, Open: 1701)? ATF Temperature sensor faulty (P1712)? Stop lamp s/w faulty (P0703)? Communication harness open (P1749)

- TCM faulty (Engine check lamp ON)- After IG ON until first time stop lamp S/W comes OnOFF.

Clutch To Clutch Shift ControlAs can be seen in the solenoid valve layout in Hydraulic Control System,there are major differences between the previous A/T and New A/T.

In previous A/T, there were only two solenoid valves to enable shift andone solenoid valve to control hydraulic pressure which resulted ininaccurate shift and rough ride.

There are solenoid valves for each clutch & brake which enable control of both thedisengaging and engaging clutch simultaneously for independent control. This system

provides a much smoother shift and comfortable ride as well as preventing Enginerun-up or clutch interlock. In addition to advanced shift feeling, the 1st gear isselected at the creep state for eliminating the shift shock during 2nd gear 1st gear.

Under cold condition (below -20C), the solenoid valve duty ratio is reduced from


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61.3Hz to 34.64Hz, because the fluidity is too slow.

Skip Shift ControlSkip shift is made possible in the new A/T.4 2, 3 1 (4A/T)

Reduction in shifting time (approx 0.6 second).

Feedback Shift ControlThe turbine speed is monitored and controlled during shifting to satisfy target turbinespeed which is accomplished by feedback control of solenoid valve duty value.Therefore the compensation of torque for the outworn engine or A/T is possible. This

has resulted in the ability to control the change in torque during shifting and producesmooth shift and better shift feeling. Feedback shift control is also applicable in

ND and NR.


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Mutual ControlThe TCM monitors various information such as vehicle speed, gear

position and engine torque then during upshift, it requests the ECM toretard ignition timing to lower torque. This produces small change in

torque during upshift, hence smooth shift and increase in shift feeling

Damper Clutch ControlThe Lock-up clutch is designed in a torque converter for the fuel economy.The lock-up clutch works in low speed range as minor slip.And it operates in high speed range as Full lock-up. Low fuel consumption and


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silence can be obtained with combination of Partial lock-up and Full lock-up control.The damper clutch is operated in 3rd and 4th gear in 4-speed ATA.In addition, Lock-up control is adapted in order to improve the fuel economy, whenreducing vehicle speed too.

Damper clutch operating range

As all the conditions below are satisfied, it locked up. The cross point of throttleopening and turbine rpm is within shadowed area.

- D range (more than 2nd speed), but damper clutch operating in 2nd speed, theATF temperature must be higher than 125 .

- The TCM does not control under N D or N R. Uphill (above 5%) longer than1.5sec. : Reducing speed Lock-upDuring this control, the vehicle is running uphill (less than 2.5%) for 1sec., the

partial lock-up control is functioned again.- Oil temperature is above 50 under full lock-up.- Oil temperature is above 70 under minor slip.- The system is not under Fail - Safe (3rd gear hold) condition.

Uphill (above 5%) longer than 1.5sec. : Reducing speed Lock-upDuring this control, the vehicle is running uphill (less than 2.5%) for 1sec., the

partial lock-up control is functioned again.


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Communication ProtocolIntegrated ECMThe communication method and protocol differ according to the type ofengine management system the MS-Car adopts. There are two

types.

Controller Area Network (CAN)Previously, for different computers in the vehicle to share the sameinformation, each signal required a different pin and wiring. However,with the introduction of a CAN system, only two lines are required toachieve the same function. The information is in digital format. Thismethod does not use a integrated ECM.Frequency : 500Kbit/sec

Input signals to TCM through CAN communication


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- Engine rpm, TPS signal- A/CON signal, Engine coolant temperature- Quantity of intake air flow, Vehicle speed- Shift holding signal (FTCS ON)Output signals from TCM through CAN communication- Request signal for torque reduction- ATF temperature, TCM type, TCM error or not- Damper clutch ON, OFF / Gear position

CAN (Controller Area Network)

Serial Communication Interface(SCI)

This uses a integrated computer which contains both the ECM and theTCM within the same unit. We will refer to this unit as integrated ECM.


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Communication Speed : 15.625Kbit/secFrequency : 20ms

If a fault occurs in either ECM or TCM, the entire integrated ECM must be replaced.

Sports ModeSports Mode Switch

Sports mode allows the manual upshift and downshift with the accelerator pedal isdepressed. The prompt response and shift would be obtained due to the continuousshifting without cutting of driving power.The response time is shorter than previous A/T, so the shifting time is also decreasedabout 0.1sec during upshift, 0.2sec during downshift.As the selector lever is pushed upward or downward one time, the gear is upshifted ordownshifted by one gear.Comparison of Shifting Time Using the Sports Mode Switch


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If the selector lever is quickly (within 0.4second) pushed toward same direction 2times, the skip shift could be obtained.


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Electronic Control ComponentsInput shaft & Output shaft speed sensor- Type : Hall sensor- Current consumption : 22mA (MAX.)

- Sensor body and sensor connector have been unified as one.

Hall Type Sensor - Structure & Interface


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Solenoid Valve for Pressure Control

- Sensor type : Normal open 3-way- Operating temperature : -30130- Frequency :

LR, 2ND, UD, OD : 61.27Hz (at the ATF temp. -20 above)

DCC : 30.64Hz KM series : 35Hz

- Internal resistance : 2.6 or more- Surge voltage : 56 V


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Wave Form with High-scan pro


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Solenoid valve ON : Hydraulic pressure isreleased from corresponding clutch or brake.

Solenoid valve OFF : Hydraulic pressure issupplied to corresponding clutch or brake.Except) DCCSV : When the DCCSV is ON, thedamper clutch is operated.

The Pressure Controlled

A/T Control Relay

The control relay supplies power to the solenoid valves.As soon as the A/T control relay is ON, the battery voltage is directlysupplied to solenoid valves and each solenoid valve is operated whenthe TCM grounds the opposite terminal. (-) Control At fail safecondition, the power is cut causing 3 gear hold.

Oil Temperature Sensor

The oil temperature sensor is of the thermistor type, and senses the automatic


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transaxle fluid temperature. Using the signal from this sensor, TCM controls the shiftpattern optimally during shift. In order to operate the damper clutch, this signal isalso referred.

- Range of temperature : -40145- Type : Separated type (High / Low temperature)- Standard value of internal resistance

Inhibitor Switch

- Type : Rotary contact type- Range of temperature : -40145


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How to Adjust Inhibitor Switch

1. Set the selector lever to the N position.2. Loosen the control cable to manualcontrol lever coupling nut to free the cable andlever.3. Set the manual control lever to the neutral

position.4. Loosen the transaxle range switch bodymounting bolts and then turn the transaxle rangeswitch body so the hole in the end of the manualcontrol lever and the hole (cross section A-A in

the figure) in the flange of the transaxle rangeswitch body flange are aligned.5. Tighten the transaxle range switch

body mounting bolts to the specified torque (10-12Nm). Be careful at this time that the positionof the switch body is not changed.6. Gently pull the transmission control cable inthe direction of front side of vehicle, and thentighten the adjusting nut.7. Check that the selector lever is in the N

position.8. Check that each range on the transmissionside operates and functions correctly for each

position of the selector lever.Inhibitor Switch - Continuity check between terminals


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electronic control system

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