SsangYong Korando II (1996-2006 year). Manual - part 276
5A-8 AUTOMATIC TRANSMISSION
SSANGYONG MY2002
Solenoid Valve Symbols
(ON/OFF Solenoids)
The solenoid symbol shown adjacent to each solenoid
on the hydraulic system schematics indicates the state
of the oil flow through the solenoid valve with the power
ON or OFF.
Normally Open (NO) Solenoid
POWER ON: Line 500 port is closed. The output port
is open to exhaust at the solenoid valve.
POWER OFF: The exhaust port is closed. The output
port is open to line 500.
Variable Pressure Solenoid Multiplexing System
Friction element shifting pressures are controlled by
the Variable Pressure Solenoid (VPS).
Line pressure is completely independent of shift pres-
sure and is a function of throttle position, gear state
and engine speed.
S5 is a proportional or variable pressure solenoid that
provides the signal pressure to the clutch and band
regulator valves thereby controlling shift pressures.
VPS pressure is multiplexed to the clutch regulator
valve, the band regulator valve and the converter clutch
regulator valve during automatic gearshifts.
A variable pressure solenoid produces a hydraulic
pressure inversely proportional to the current applied.
During a gearshift the TCM applies a progressively
increasing or decreasing (ramped) current to the
solenoid. Current applied will vary between a minimum
oaf 200 mA and a maximum of 1000 mA. Increasing
current decreases output (S5) pressure. Decreasing
current increases output (S5) pressure.
Line 500 pressure, (approximately 440 to 560 kPa), is
the reference pressure for the VPS, and the VPS output
pressure is always below line 500 pressure.
When the VPS is at standby, that is no gearshift is
taking place, the VPS current is set to 200 mA giving
maximum output pressure.
Under steady state conditions the band and clutch
regulator valve solenoids are switched OFF.
This applies full Line 500 pressure to the plunger and
because Line 500 pressure is always greater than S5
pressure it squeezes the S5 oil out between the
regulator valve and the plunger. The friction elements
are then fed oil pressure equal to Line 500 multiplied
by the amplification ratio.
When a shift is initiated the required ON/OFF solenoid
is switched ON cutting the supply of Line 500 to the
plunger.
At the same time the VPS pressure is reduced to the
ramp start value and assumes control of the regulator
valve by pushing the plunger away from the valve.
The VPS then carries out the required pressure ramp
and the timed shift is completed by switching OFF the
ON/ OFF solenoid and returning the VPS to the standby
pressure.
This system enables either the band or clutch or both
to be electrically controlled for each gearshift.
Mode Indicator Light
Depending on the application, the mode indicator light
may be used to indicate the mode that has been se-
lected or if an overheat condition exists. The mode
indicator light is usually located on the instrument
cluster.
Communication Systems
CAN
The Controller Area Network (CAN) connects various
control modules by using a twisted pair of wires, to
share common information. This results in a reduction
of sensors and wiring. TCM obtains the actual engine
speed and throttle position, vehicle speed and
accelerator position etc. from ECM via CAN without
any additional sensors.
K-Line
The K-line is typically used for obtaining diagnostic
information from the TCM. A scan tool with a special
interface is connected to the TCM via Data Link
Connector (DLC) and all current faults, stored faults,
runtime parameters are then available. The stored
trouble codes can also be cleared by scan tool.
The K-line can be used for vehicle coding at the
manufacturer’s plant or in the workshop. This allows
for one TCM design to be used over different vehicle
mod-els.
The particular code is sent to the microprocessor via
the K-line and this results in the software selecting the
correct shift and VPS ramp parameters.
Data Link Connector (DLC)
The Data Link Connector (DLC) is a multiple cavity
connector. The DLC provides the means to access the
serial data from the TCM.
The DLC allows the technician to use a scan tool to
monitor the various systems and display the Diagnostic
Trouble Codes (DTCs).
KAA5A070