Electronic Control System - SSANGYONG Rexton Y290 2012 Manual

5. ELECTRONIC CONTROL SYSTEM

1) Overview
The transmission control unit (TCU) and its input/output networks control the operations of
transmission:
- Shift timing
- Line pressure
- Clutch pressure (shift feel)
- Torque converter clutch
In addition, the TCU receives input signals from certain transmission-related sensors and
switches. The TCU also uses these signals when determining transmission operating strategy.
Using all of these input signals, the TCU can determine when the time and conditions are right for
a shift, or when to apply or release the torque converter clutch. It will also determine the pressure
needed to optimise shift feel. To accomplish this, the TCU operates six variable bleed control
solenoids and four ON/OFF solenoids to control the operations of transmission.
2) Transmission Control Unit (TCU)
TCU use the power from the ignition power supply to start and stop its operation. TCU is
connected to the transmission with 26-pin connector. TCU processes the signals and information
(analog and digital) through CAN bus from the sensors.
- Transmission input speed
- Transmission output speed
- Accelerator pedal position
- Gear selector position
- Engine torque
- Engine speed
This information is used by the TCU to decide which shift pattern to select and for shift energy
management. Electro-hydraulic solenoid valves and variable bleed solenoids control the
transmission gear changes.
Six variable bleed solenoids and four on/off solenoids are used to direct transmission fluid flow to
control the fluid pressure within the three clutches and two bands. Separate pressure regulators
are used exclusively for torque converter clutch control and main transmission line pressure.
The TCU monitors all TCU inputs and outputs to confirm correct system operation. If a fault
occurs the TCU is able to perform default action and inform the driver of the problem through the
instrument cluster warning lights. Detailed information is available via trouble codes which can be
read with the service tool.
- Transmission oil temperature
- Brake pedal status
- Engine oil temperature
- Engine coolant temperature
- Ambient air temperature
- Barometric pressure
3650-01