Automatic Transmission/Transaxle: Description and Operation

P311 HYBRID TRANSMISSION / TRANSAXLE: ELECTRONIC SHIFT LEVER SYSTEM: SYSTEM DIAGRAM









P311 HYBRID TRANSMISSION / TRANSAXLE: ELECTRONIC SHIFT LEVER SYSTEM: SYSTEM DESCRIPTION

1. SYSTEM DESCRIPTION

The electronic shift lever system electrically controls the parking lock mechanism by using an actuator.

The transmission control ECU assembly locks/unlocks gearshift control based on lock/unlock request signals from the certification ECU (smart key ECU assembly).

The transmission control ECU assembly controls the shift control actuator when gearshift control is unlocked, and also controls the entire system based on information from the hybrid vehicle control ECU.

The transmission control ECU assembly detects DTCs when there are any malfunctions in the system, and informs the driver of selected malfunctions by illuminating the P position switch indicator light and master warning light, and indicating an error message on the multi-display.

2. SYSTEM DIAGRAM





Input and Output Signals of Each ECU





3. FUNCTION OF EACH COMPONENT





4. OPERATION DESCRIPTION

(a) Operation when switching to park (P):





(1) When the P position switch (transmission shift main switch) is pushed to activate the 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 assembly.

(4) After receiving the signal, the transmission control ECU assembly activates the shift control actuator in order to lock the parking lock mechanism.





(5) The transmission control ECU assembly 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.

(6) The P position switch indicator light is turned on.

(b) Operation to switch from park (P) to a shift state other than park (P):





(1) When the hybrid system is started (the vehicle is ready to be driven) and the shift lever is moved to R, N, or D 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 assembly as a "P lock release" operation demand signal.

(3) After receiving the signal, the transmission control ECU assembly activates the shift control actuator in order to unlock the parking lock mechanism.





(4) The transmission control ECU assembly controls motor rotation angle based on signals from the rotation angle sensor in the shift control actuator.

(5) The P position switch indicator light is turned off.

5. SHIFT STATE CHANGE FUNCTION

(a) The electronic shift lever system comprehensively determines vehicle conditions and changes the shift state, 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 state is automatically changed to park (P) and all power is turned off.





6. REJECT FUNCTION

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





7. P POSITION SWITCH INDICATOR LIGHT CONTROL

(a) The indicator light comes on when park (P) is engaged, goes off when park (P) is disengaged and blinks when a system malfunction occurs.

Indicator Light





NOTICE:
Even if the system has returned to normal, the indicator light does not return to normal without the shift lever being moved from the home position to select a state other than park (P). (Normal refers to the indicator light coming on when park (P) is engaged and going off when park (P) is disengaged.)