SSANGYONG KYRON 2010.01 Manual page 558

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3410-01
5. CONTROL SYSTEMS
BTRA M74 4WD automatic transmission consists of two control systems. One is the electronic
control system that monitors vehicle parameters and adjusts the transmission performance.
Another is the hydraulic control system that implements the commands of the electronic control
system commands.
6. ELECTRONIC CONTROL SYSTEM
The electronic control system comprises of sensors, a TCU and seven solenoids. The TCU
reads the inputs and activates the outputs according to values stored in Read Only Memory
(ROM).
The TCU controls the hydraulic control system. This control is via the hydraulic valve body,
which contains seven electromagnetic solenoids. Six of the seven solenoids are used to control
the line pressure, operate the shift valves and the torque converter lock-up clutch, and to turn
ON and OFF the two regulator valves that control the shift feel.
The seventh solenoid is the proportional or Variable Pressure Solenoid (VPS) which works with
the two regulator valves to control shift feel.
1) Transmission Control Module (TCU)
The TCU is an in-vehicle micro-processor based transmission management system. It is
mounted under the driver's side front seat in the vehicle cabin.
The TCU contains :
- Processing logic circuits which include a central microprocessor controller and a back-up
memory system.
- Input circuits.
- Output circuits which control external devices such as the Variable Pressure Solenoid
(VPS) driver, On/ Off solenoid drivers, a diagnostics output and the driving mode
indicator light.
ION 4-SPEED
KYRON 2010.01