SSANGYONG Rexton Y200 Manual page 976

5A-4 AUTOMATIC TRANSMISSION
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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.
Processing Logic
Shift schedule and calibration information is stored in
an Erasable Programmable Read Only Memory (EPROM).
Throttle input calibration constants and the diagnostics
information are stored in Electrically Erasable Program-
mable Read Only Memory (EEPROM) that retains the
memory even when power to the TCM is disconnected.
TCM continuously monitors the input values and uses
these, via the shift schedule, to determine the required
gear state. At the same time it monitors, via the
solenoid outputs, the current gear state, whenever the
input conditions change such that the required gear
state is different to the current gear state, the TCM
initiates a gear shift to bring the two states back into
line.
Once the TCM has determined the type of gearshift
required the TCM accesses the shift logic, estimates
TCM Inputs
To function correctly, the TCM requires engine speed,
vehicle speed, transmission fluid temperature, throttle
position, gear position and Kickdown Switch inputs to
determine the variable pressure solenoid current ramp
the engine torque output, adjusts the variable pressure
solenoid ramp pressure then executes the shift.
The TCM continuously monitors every input and output
circuit for short or open circuits and operating range.
When a failure or abnormal operation is detected the
TCM records the condition code in the diagnostics
memory and implements a Limp Home Mode (LHM).
The actual limp home mode used depends upon the
fail-ure detected with the object to maintain maximum
drive-ability without damaging the transmission. In
general input failures are handled by providing a
default value. Output failures, which are capable of
damaging the transmission, result in full limp mode
giving only third or fourth gear and reverse. For further
details of limp modes and memory retention refer to
the Diagnostic Trouble Code Diagnosis Section.
The TCM is designed to operate at ambient
temperatures between - 40 and 85 °C (- 40 and 185 °F).
It is also protected against electrical noise and voltage
spikes, however all the usual precautions should be
observed, for example when arc welding or jump
starting.
and on/off solenoid states. This ensures the correct
gear selection and shift feel for all driving conditions.
The inputs required by the TCM are as follows;
KAA5A030
SSANGYONG Y200