Shift Interlock: Description and Operation

System Outline

Under this system, operating signal of shift lever is sent to hybrid vehicle control ECU to control hybrid motor, which changes shift ranges (R, N, D, B) electrically. When shift is put in P range, transmission control ECU receives operating signal from hybrid vehicle control ECU and activates parking lock electrically.

1. Shift Range Change Function
Gear can be shifted to any shift range under condition when vehicle can drive except when reject function is in operation.
When vehicle cannot drive with power SW at IG ON position, gear can be shifted only to P and N range.
When vehicle cannot drive with power SW at ACC ON position, gear can be shifted only to P range.
When power SW is at OFF position, gear cannot be shifted to any range.
When main SW is operated at vehicle stop after starting hybrid system, gear is automatically changed to P range from any other gear range and turns off power supply.

2. Reject Function
Changing gear may not effect to change range under certain vehicle condition. Under such condition, warning buzzer of combination meter sounds to show the rejection and call for driver's attention. Followings are shift operations and shift range conditions under which reject function is activated.
- When gear is shifted from P range to other range without applying brake pedal, gear stays in P range.
- Main SW cannot put gear in P range during driving but changes to N range.
- Shift change to forward or backward during driving changes gear to N range.
- When gear is changed from other range than D range to B range, gear is changed to N range automatically.

3. Combination Meter Indication
The combination meter shows present shift range position. Other shift range positions than D or B range are not shown in lighting in the combination meter. This is to avoid unnecessary shifting operation to B range from other shift position except D range.

4. Operation of Parking Lock
Operation signal from/to P range is sent from main SW or power SW to transmission control ECU through hybrid vehicle control ECU. At that time the transmission control ECU operates P CON MTR relay, activates parking lock actuator with appropriate control of electric current, and lights up main SW when shift is at P range. If the system has abnormality on parking lock operation, it tells the system abnormality to the driver by lighting up master warning light on combination meter, displaying warning of the system abnormality on the multi-display, and blinking indicator light of main SW.

5. Operation at Electric Power OFF
Under electric power OFF, transmission control ECU receives signal from power source control ECU by multi-communication, and sends shift range position information to hybrid vehicle control ECU. The hybrid vehicle control ECU sends signal to power source control ECU to tell whether it is right or wrong condition to turn off electric power. Accepted conditions for electric power OFF are as follows;
- When hybrid vehicle control ECU is not sending request signal for parking lock release with shift range in P range position.
- With shift range is at other range than P range, when hybrid vehicle control ECU is outputting signal that hybrid system is not running or request signal for parking lock.
- When there is abnormal motor's not running condition with paring lock in operation, and hybrid system is not running and parking brake is being applied.