Transaxle Operational Strategies
Transaxle Operational Strategies
Automatic Gearshift Control
In automatic gearshift control, based on each gearshift pattern, Shift Solenoid A (SSA) and Shift Solenoid B (SSB) turn ON or OFF and Shift Solenoid C (SSC), Shift Solenoid D (SSD), Shift Solenoid E (SSE) and Shift Solenoid F (SSF) are operated linearly according to information that includes vehicle speed, the degree to which the accelerator is open and brake signal.
Driver Adaptive Shift Control
This automatic transaxle does not have a driving mode selection switch that allows drivers to select a mode themselves. The vehicle is ordinarily in adaptive mode. However, when specific conditions are met, the Transmission Control Module (TCM) selects a shifting pattern appropriate to driving conditions from all of the shifting patterns and switches automatically.
- GREEN - Mode 1 - Switched from mode 2 to warm up the transmission fluid. This mode acts to protect the transaxle before the adaptive mode.
- GREEN - Mode 2 - After engine start-up, warm-up speed is increased for a certain period when transmission fluid temperature is low and the vehicle speed is 0.
- HIGH TEMP - When transmission fluid temperature becomes too high, this mode activates lock-up at an earlier timing to stop the temperature rise and lower the temperature.
- DOWN SLOPE - When driving down a slope, the TCM detects a down slope based on the engine control unit signal and output rpm. TCM switches to down slope mode to alleviate the load to the brake by downshifting.
Gear Shift Control
When the selector lever is moved from N to D or from N to R, after the engine is started, shift control solenoid assembly SSC, SSD or SSE is used for the fluid pressure required by C1 clutch or C3 clutch and appropriately regulated fluid pressure is supplied to the clutch, engaging smoothly without shock.
Reverse Converter Control
If the selector lever is moved from N to R while the vehicle is moving forward and the transaxle shifts into REVERSE, the wheels will be locked, which is extremely dangerous. In order to avoid this, the TCM inhibits the transaxle from shifting into REVERSE while moving forward.
Torque Converter Clutch (TCC)
Based on output rpm signals, signals from the engine control unit (engine rpm and throttle opening) and vehicle speed, a smooth engagement is carried out through linear control of the Torque Converter Clutch (TCC) solenoid. Also, the slip rate is detected by adding input rpm signals and slip control is carried out.
- Engagement Control - control is carried out using a TCC solenoid. The TCC solenoid is linearly turned ON and OFF. The clutch inside the torque converter is operated and the pump impeller and turbine runner are connected. Through this, the engine and the transaxle are coupled and engine output is connected directly to the transaxle, eliminating transaxle loss and enhancing fuel economy
- Slip Control - control is carried out using a TCC solenoid. The TCC solenoid is linearly turned ON and OFF and the clutch within the torque converter is operated outside of the engagement range. The clutch slides without being in a completely coupled condition, increasing transaxle efficiency and enhancing fuel economy.