Transmission Control Systems: Description and Operation

HYBRID TRANSMISSION / TRANSAXLE: ELECTRONIC SHIFT LEVER SYSTEM:

SYSTEM DIAGRAM





Input and output signals of each ECU






SYSTEM DESCRIPTION

1. SYSTEM DESCRIPTION
The electronic shift lever system electrically controls the parking lock mechanism by using the actuator.
The transmission control ECU controls the shift control actuator, and also controls the entire system based on information from the hybrid vehicle control ECU.
The transmission control ECU detects DTCs when there are any malfunctions in the system, and informs the driver of the malfunction by illuminating the P position switch indicator light and master warning light, and indicating an error message on the multi-display.
2. FUNCTION OF EACH COMPONENT






3. OPERATION DESCRIPTION
(a) Operation to switch to the P position:




(1) When the P position switch is turned on to activate parking lock, a signal is sent to the hybrid vehicle control ECU.
(2) The hybrid vehicle control ECU determines whether "P lock" is possible or not based on this signal and other vehicle information.
(3) If the hybrid vehicle control ECU determines that "P lock" is possible, it sends a "P lock" operation demand signal to the transmission control ECU.




(4) After receiving the signal, the transmission control ECU activates the shift control actuator in order to lock the parking lock mechanism, and turns on the P position switch indicator light.
(5) The transmission control ECU controls motor rotation angle based on signals from the rotation angle sensor in the shift control actuator.




HINT: In the cycloid reduction mechanism, the output shaft is linked to the external gear. Together, they rotate only a single tooth when the eccentric adapter, which is linked to the motor, rotates once. Driving force is increased in this way so that the parking lock mechanism can be switched even when high output is required for parking on a hill, etc.

(b) Operation to switch to a non-P position:




(1) When the hybrid system is started (the vehicle is ready to be driven) and the selector lever is moved to the R, N, or the D position with the brake pedal depressed, a signal is sent to the hybrid vehicle control ECU.
(2) This signal is then sent from the hybrid vehicle control ECU to the transmission control ECU as a "P lock release" operation demand signal.




(3) After receiving the signal, the transmission control ECU activates the shift control actuator in order to unlock the parking lock mechanism, and turns off the P position switch indicator light.
(4) The transmission control ECU controls motor rotation angle based on signals from the rotation angle sensor in the shift control actuator.
4. SHIFT POSITION CHANGE FUNCTION
(a) The electronic shift lever system comprehensively determines vehicle conditions and changes the shift position, as shown in the following chart, by cooperating with the shift control function of the hybrid system (except when the reject function, described later, is in operation).
(b) Other than indicated in the following chart, when the power switch is turned OFF with the vehicle stopped, the shift position is automatically changed to the P position.





5. REJECT FUNCTION
(a) In the electronic shift lever system, there may be a situation in which a shift change cannot be done for safety reasons. When attempting to move the selector lever in such a situation, the system sounds a reject buzzer inside the meter and changes the shift position as shown in the following table.