System Description

SYSTEM

SHIFT CHANGE CONTROL : System Description

Input/Output Signal Chart





The clutch pressure control solenoid is controlled by the signals from the switches and sensors. Thus, the clutch pressure is adjusted to be appropriate to the engine load state and vehicle driving state. It becomes possible to finely control the clutch hydraulic pressure with high precision and a smoother shift change characteristic is attained.





The clutch is controlled with the optimum timing and oil pressure by the engine speed, engine torque information, etc.





*1: Full phase real-time feedback control monitors movement of gear ratio at gear change, and controls oil pressure in real-time to achieve the best gear ratio.

BLIPPING CONTROL

This system makes transmission clutch engage readily by controlling (synchronizing) engine revolution according to the (calculation of) engine revolution after shifting down.
- "BLIPPING CONTROL" functions.
- When downshifting by accelerator pedal depression.
- When downshifting by the manual mode.





- TCM selects "BLIPPING CONTROL" or "NORMAL SHIFT CONTROL" according to the gear position, the selector lever position, the engine torque and the speed when accelerating by pedal depression.
- Engine speed control demand signal is transmitted from TCM to ECM under "BLIPPING CONTROL".
- ECM synchronizes the engine speed according to the engine speed control demand signal.











IDLE NEUTRAL CONTROL

Input/Output Signal Chart





The TCM activates low brake solenoid valve and controls the low brake oil pressure to the low pressure level if the driver does not intend to start the vehicle while the vehicle is being stopped in the "D" position. Therefore, the low brake is in the release (slip) status and the power transmission route of A/T is the same status as the
"N" position. This can decrease the engine load and improves the fuel economy because the drive force of engine is not transmitted to the output shaft of A/T.
Idle Neutral Control Start Condition
Idle neutral control starts when all of the following conditions are satisfied. However, the control ends when any one of the following conditions becomes insufficient during idle neutral control.





NOTE:
The idle neutral control is terminated or prohibited when the TCM and ECM detect that the vehicle is in any of the conditions as per the following.
- Engine cooling water temperature and A/T fluid temperature are below or above a prescribed temperature.
- A/T malfunction occurs.
- DTC is detected.
- Fail-safe mode activates.
- Idle neutral control is performed continuously for a certain period of time.
Idle Neutral Control Resume Condition
Idle neutral control can be resumed when its start condition is fulfilled after any of the following operations is performed (unless a malfunction occurs in the vehicle).
- After driving at more than a prescribed speed.
- When idle neutral control start conditions are fulfilled for a certain period of time.