SSANGYONG KYRON 2005.10 Manual page 70

0-16 3110-01
(3) CIRCUIT DESCRIPTION
A. FUNCTION
TCU controls the gear groups according to the driving conditions.
It receives the driving data from many sensors and switches as input signals.
It is also connected with ECU, HECU, instrument panel and selector lever control unit.
▶ Shifting Method
Basic shift operation includes up-shift and down-shift for all gear groups. The shift control
unit determines driving resistance, accelerator pedal position, vehicle speed and some
parameters (road surface condition, up hill and down hill gradients, trailer driving
conditions, catalytic converter conditions, driving habits and automatic transmission oil
temperature) to select a shift gear.
▶ Down Shif
When engine speed increases excessively, the down shift does not occur.
To get an engine brake effect during downhill driving, the current gear is maintained in
speed control mode.
▶ Engine RPM Adjustment
During shifting, the engine torque is reduced to optimize the shift operation by delaying the
ignition time.
▶ Lock-Up Clutch Control
The lockup clutch in torque converter is activated in 3rd, 4th and 5th gear and operates in
sequence via PWM solenoid valve.
▶ Others
The transmission is automatically controlled to compensate durability and wear.
The shift control values such as shifting point, shifting time, pressure during shifting, and
lockup clutch control are permanently saved and the diagnosis is partially available.
B. SELECTOR LEVER CONTROL UNIT
▶ Selector lever control unit functions as follows
- Informing the selector lever's position to other units via CAN.
- Turning on the selector lever indicator while tail lamp is turning on.
- Turning on the back-up lamp during reverse driving.
Operating the parking/reverse lock system.
CIRCUIT
KYRON 2005.10
C. MODE SWITCH
The mode switch is installed beside the selector lever and it has two modes of "S"
mode (Standard Mode) and "W" mode (Winter Mode).
- "S" mode is used in normal driving (starts off with 1st gear). TCU (Transmission
Control Unit) provides pleasant driving by changing the shifting pattern according to the
driving habits (downhill gripping: approx. 11 ~ 13.5 %)
- When "W" mode is selected, the Winter mode indicator in meter cluster comes on,
and the vehicle starts off with 2nd gear to achieve smooth starting on the icy or slippery
road.
In winter mode, the up shift becomes faster and the down shift becomes slower for improving
fuel consumption.
The "W" mode is automatically changed to "S" mode in full throttle or kick-down
operation. The vehicle can starts off with 2nd reverse gear (gear ratio: 1.92 ~ 1.93) when the
"W" mode is selected.
It is very useful on icy and slippery road. However, in this case, the "W"
be selected before placing the selector lever to "R"
▶ Even though "W" mode is selected, the vehicle starts off with
1st gear in following
When the system recognizes the mode switch operation, the selector lever control unit
sends the control signal TCU via CAN communication.
- When the selector lever is in "1" position.
- When fully depressing the accelerator pedal or when starting off with kick-down
condition.
D. REVERSE/PARKING (R/P) LOCK SYSTEM
Reverse (R) lock system is a safety system that prevents the selector lever from shifting
to "P" or "R" position by activating the solenoid valve when the selector lever unit
determines that the vehicle speed exceeds 10km/h by checking the speed signal from wheel
speed sensor via CAN communication.
Parking (P) lock system uses the signals from brake switch other than conventional cable
system to shift to other positions. The wiring harness for detecting brake switch operation is
connected to selector lever control unit.
E. STARTER LOCK-OUT CONTACT SWITCH
The starter lock-out contact is installed beside oil temperature sensor and is actuated by a
cam rail, which is located on the latching plate.
In the selector lever positions "P" and "N", the permanent magnet is moved away from
the reed contact. This opens the reed contact and the transmission control module receives
an electrical signal. The transmission control module activates the starter lock-out relay
module. This closes the electrical circuit to the starter in selector lever positions "P"
and "N" via the starter lock-out relay module. In other words, when the selector lever is
in driving positions, the contact is closed and the starter cannot be operated.
switch should
position.