Gear System Description - Electronic Control System (2017)
Functional Diagram
The electronic control system consists of the PCM, sensors, switches, and solenoid valves. The PCM receives input signals from the sensors, switches, and other control units, processes data, and outputs signals for the engine control system and the gear unit control system. The gear unit control system includes clutch pressure control. The PCM determines the drive mode based on the information sent from each sensor and control unit. The PCM actuates solenoid valves A and B to engage over drive clutch.
Clutch Pressure Control
The PCM actuates solenoid valves A and B to control the over drive clutch pressure. The PCM receives input signals from the various sensors, switches and control units, then processes the data to determine the drive mode. When the drive mode is shifted from hybrid drive mode to engine drive mode, the PCM actuates solenoid valve B and makes the over drive clutch ready to be engaged. To reduce the shock caused during the engagement, the PCM controls the RPM of the engine and traction motor to be synchronized with each other before engaging the over drive clutch. Once speed of the engine and traction motor are synchronized, the PCM actuates solenoid valve A, and engages the over drive clutch. When the drive mode is shifted from engine drive mode to hybrid drive mode, the PCM turns off solenoid valve A and B, and releases the over drive clutch.