ELECTRONIC CONTROL TRANSMISION, LE THANH PHUC

ELECTRONIC CONTROL TRANSMISSION Le Thanh Phuc Faculty of Automotive Engineering University of Technical Education Ho Chi Minh City Email: phuclt@hcmute.edu.vn Introduction • The Electronic Control Transmission is an automatic transmission which uses electronic technology to control transmission operation • • The transmission is virtually the same as a fully hydraulic controlled transmission It includes electronic solenoids, sensors, and an electronic control unit Introduction (Cont’d) • The electronic sensors monitor the speed of the vehicle, speed of the input shaft, gear position selection and throttle opening, providing this information to the ECU • The ECU then controls the operation of the clutches and brakes based on this data and controls the timing of shift points and torque converter lock-up and maintains on-board diagnosis Planetary Gear Set • The planetary gear unit is used to increase or decrease engine torque, increase or decrease vehicle speed, reverse direction of rotation or provide direct drive • It is basically a lever that allow the engine to move heavy loads with less effort Planetary Gear Set Multiplate Clutch • The multiplate clutch connects two rotating components of the planetary gear set • Because this assembly rotates while the vehicle is in motion, it presents a unique challenge to ensure fluid under pressure reaches the clutch and holds the clutch engaged for thousand of miles of services Multiplate Clutch Band Brake • The brake band is located around the outer circumference of the direct clutch drum • One end of this brake band is located to the transmission case with a pin, while the other end contacts the brake piston which is operated by hydraulic pressure Band Brake One-way Clutch • One-way clutch is a holding device which requires no seals or hydraulic pressure to apply • Their operation is similar in that they both rely on wedging metal between two races 10 Speed Sensor • The speed sensor signal originates from a sensor measuring transmission/transaxle output speed or wheel speed • Different types of sensors have been used depending on models and applications • On some vehicles, the vehicle speed sensor signal is processed in the combination meter and then sent to the ECU 22 Speed Sensor 23 Stop Light Switch • The stop light switch is mounted on the brake pedal bracket • When the brake pedal is depressed, it sends a signal to the STP terminal of the ECU informing it that the brakes have been applied • The ECU cancels torque converter lock-up when the brake pedal is depressed 24 Stop Light Switch 25 Solenoid Valves • Solenoid valves are electro-mechanical devices which control hydraulic circuits by opening a drain for pressurized hydraulic fluid • Shift solenoid valves (No and No 2): these solenoid valves are mounted on the valve body and are turned on and off by electrical signals from the ECU, causing various hydraulic circuits to be switched as necessary • Lock-up control valve (No 3): The lock-up control solenoid valve is mounted on the transmission exterior It controls line pressure which affects the operation of the torque converter lock-up system 26 Solenoid Valves 27 First Gear 28 29 Second Gear 30 31 Third Gear 32 33 Fourth Gear 34 35 Shifting Gear 36 [...]... Light Switch 25 Solenoid Valves • Solenoid valves are electro-mechanical devices which control hydraulic circuits by opening a drain for pressurized hydraulic fluid • Shift solenoid valves (No 1 and No 2): these solenoid valves are mounted on the valve body and are turned on and off by electrical signals from the ECU, causing various hydraulic circuits to be switched as necessary • Lock-up control valve... information on the selected gear range from the shift position sensor, located in the neutral start switch, and determines the appropriate shift pattern • The neutral start switch is actuated by the manual valve shaft in response to gear selector movement 16 Neutral Start Switch 17 Throttle Position Sensor • This sensor is mounted on the throttle body and electrically senses how far the throttle is open and... the vehicle’s driveability would suffer if the transmission were shifted into overdrive or converter clutch were locked-up 20 Engine Coolant Temperature Sensor 21 Speed Sensor • The speed sensor signal originates from a sensor measuring transmission/transaxle output speed or wheel speed • Different types of sensors have been used depending on models and applications • On some vehicles, the vehicle speed... data to the ECU • By relaying the throttle position, it gives the ECU an indication of engine load to control the shifting and lock-up timing of the transmission 18 Throttle Position Sensor 19 Engine Coolant Temperature Sensor • The engine coolant temperature sensor monitors engine coolant temperature and is typically located near the cylinder head water outlet • A thermistor is mounted within the... from the ECU, causing various hydraulic circuits to be switched as necessary • Lock-up control valve (No 3): The lock-up control solenoid valve is mounted on the transmission exterior It controls line pressure which affects the operation of the torque converter lock-up system 26 Solenoid Valves 27 First Gear 28 29 Second Gear 30 31 Third Gear 32 33 Fourth Gear 34 35 Shifting Gear 36