SSANGYONG KORANDO 2012 Service Manual

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1. OVERVIEW
2WD4WD
The Model 6F24 6 speed automatic transaxle is electronically controlled. The control system is
comprised of the following components:
External transaxle control unit (TCU)
Input and output speed sensors
Six variable force solenoids(VFS) and two on/off solenoids
Torque converter
ATF temperature sensor -
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TCU controls the oil pressure for various internal clutches and brakes to select the gear. It also controls
the electronic elements, shift pressure and torque converter slip. If the system is defective, TCU provides
FMEC (Failure Mode Effect Control) to maintain the functionality of transaxle. This keeps the basic
function of transaxle (gear selection) even when there are failure in controls and power supply.
There are selector shaft position sensor (inhibitor switch) and oil temperature sensor in transaxle. In
manual mode, TCU receives the information from TGS (Transmission Gear Selector) through PCB
(Printed Circuit Board) when driver selects the manual shift mode. TCU communicates with other electric
control modules through CAN. In order to ensure a safe driving state and to prevent damage to the
automatic transmission, TCU switches to Limp-Home mode in the event of critical faults.

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2. FEATURES
1) Advantages
Early Downshift with Hard Braking and Skip Shifts ▶
When heavy braking is detected, the transaxle downshifts early and skips gears to provide increased
engine braking to provide gear selection for tip-in.
Gear Hold going Uphill/Downhill ▶
If the accelerator pedal is released when traveling uphill, upshifts are prevented to reduce busyness on
grades. If the accelerator pedal is released when traveling downhill, upshifts are prevented to enhance
engine braking.
Drive and Reverse Engagement ▶
A soft engagement feature avoids harsh take up of drive when selecting Drive or Reverse. This is
achieved by limiting engine speed and engine torque which results in a rapid, but progressive
engagement of either Drive or Reverse when moving from the Park or Neutral positions. Drive and
Reverse engagements from either Park or Neutral are performed in less than 2.2 seconds. There is no
drive engagement prevention strategy implemented on the transaxle system as there is sufficient engine
strategy to protect the system. However, reverse engagement is prevented until vehicle speed is less
than 7 km/h.

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2) Transaxle Cooling
The transaxle cooling system ensures rapid warm-up and constant operating temperature resulting in
reduced fuel consumption and refined shift quality.
It also includes a cooler by-pass within the hydraulic system to allow sufficient lubrication to the transaxle
drivetrain in the event of a blockage in the transaxle cooler.
3) Shift Strategy
Gear Change ▶
Transaxle gear change is controlled by the
TCU. The TCU receives inputs from various
engine and vehicle sensors to select shift
schedules and to control the shift feel and
torque converter clutch (TCC) operation at each
gear change.
Coast down ▶
Coast down down shifts occur at 0% pedal
when the vehicle is coasting down to a stop.
Torque Demand ▶
Torque demand down shifts occur
(automatically) when the driver demand for
torque is greater than the engine can provide at
that gear ratio. If applied, the transaxle will
disengage the TCC to provide added
acceleration.

03-14
3. MODES AND FUNCTIONS
This allows the driver to define the highest
possible gear by selecting “+” or “-” on the
gear selector when the lever is in the “M”
position. When the lever is first moved to the
manual “M” position the transaxle will select
one lower gear than current gear.
When driving on a slippery road, push the tip switch forward into the "+" position in "M" position.
This causes the transaxle to shift into the 2nd gear which is better for smooth driving on a slippery
road.

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1st Gear State ▶
The 1st gear state will display on the
instrument cluster. Unlike the normal 1st gear,
engine braking will be available in this manual
1st state. -
2nd Gear State ▶
The 2nd gear state will display on the
instrument cluster. 2nd gear has engine braking
available. -
3rd Gear State ▶
The 3rd gear state will display on the
instrument cluster. 3rd gear has engine
braking available. -
4th Gear State ▶
The 4th gear state will display on the
instrument cluster. 4th gear has engine
braking available. -
5th Gear State ▶
The 5th gear state will display on the
instrument cluster. 5th gear has engine
braking available. -
6th Gear State ▶
The 6th gear state will display on the
instrument cluster. 6th gear has engine
braking available. -
STD type
SVC type

03-16
4. LIMP HOME MODE
When the transaxle is defective ▶
In the event of a system fault, the TCU also provides for failure mode effect control (FMEC) to maintain
maximum functional operation of the transaxle. (There are 3 FMEC modes, mechanical limp-home
mode, electrical limp-home mode, limp-home mode C.)
In the event of a total loss of control or electrical power, the basic transaxle functions (Park, Reverse,
Neutral and Drive) are retained. The 4th and reverse gear ratios with the torque converter clutch in the
unlocked state are the retained gear states the hydraulic system supports without any electrical
assistance. (Mechanical limp-home)
If the speed sensor circuit is failed, the gear is fixed to 4th gear, but manual shifting
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96008b008c0050>
If the inhibitor switch signals are invalid, shifting to1st and 2nd gear is forbidden. (Limp-home C)
The TCU communicates with other vehicle electronic control modules by the controller area network
(CAN). If a major fault is developed, the transaxle may not accomplish the intelligent shift control. The
TCU controls the transaxle with preset values.
The TCU also provides for transaxle diagnostics, which meet the requirements of OBD II regulation,
monitoring all components which may effect vehicle emissions. 1.
2.
3.
4.
5.
6.
Towing the automatic transaxle equipped vehicle ▶
Flat-bed equipment is the best method of moving a disabled vehicle to avoid any damages.
For AWD vehicle: The vehicle must be towed with a wheel lift and dollies or flatbed equipment with
all the wheels off the ground.
For 2WD vehicles: It is acceptable to tow the vehicle with the rear wheels on the ground without
dollies and the front wheels off the ground. When being towed by a commercial towtruck and
wheel dollies are not available, the front of the vehicle should be lifted, not the rear. -
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5. TRANSAXLE ELECTRONIC CONTROL SYSTEM
1) General Information
The transmission control unit (TCU) and its input/output network control the following transmission
operations:
Shift timing
Line pressure
Clutch pressure (shift feel)
Torque converter clutch -
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also uses these signals when determining transaxle 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.
2) TCU (Transmission Control Unit)
The transaxle control unit (TCU) is mounted
under the driver's seat and controls the operation
of the transaxle.
Internal sensors and signals received across the
CAN bus in analogue and digital forms such as:
Transaxle input speed
Transaxle output speed
Accelerator pedal position
Gear selector position
Engine torque
Engine speed
Transaxle fluid temperature
Brake pedal status
Engine oil temperature
Engine coolant temperature
Ambient air temperature
Barometric pressure -
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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.

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6. CAN NETWORK
The TCU sends signals to be used by other vehicle systems via the CAN bus, such as:
Selector lever position
Selected gear state
Manual mode activation
Transaxle fluid temperature
Engine torque reduction requests -
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Schematic Diagram of Network Communication ▶

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7. POWER TRANSFER
Power transfer modes are as follow:
Manual: 1st gear (position M)
Drive: 1st gear
Drive: 2nd gear
Drive: 3rd gear
Drive: 4th gear - limp home mode
Drive: 5th gear
Drive: 6th gear -
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1) Overview
Name Component
C1 OVER DRIVE CLUTCH
C2 35R CLUTCH
B1 LOW & REVERSE BRAKE
B2 2/6 BRAKE
B3 UNDER DRIVE BRAKE
1F 1-2 ONE WAY CLUTCH
GEARCLUTCH BRAKE
OWC Gear Ratio
OD 35R 26 LR UD
1ST△*O O 4.212
2ND O O 2.637
3RD O O 1.800
4TH O O 1.386
5TH O O 1.000
6TH O O 0.772
REV O O 3.385
N.P O
(1) Gear Selection and Engagement Element
Operation when vehicle speed under 5kph *

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2) Operation in Each Gear Position
(1) Neutral/Park
Lower & reverse brake (LR/B) op<008c00990088009b008c008b004702e700470076009d008c0099008b00990090009d008c0047004f00760056006b00500047008f009c0089004700930096008a0092008c008b004702e7004700740090008b008b0093008c0047004d00470099008c008800
9900470047004f00740070006b0047004d0047>
REAR) P/C locked
<007000950097009c009b0047009a008f0088008d009b004700990096009b0088009b008c008b004702e700470079008c008800990047009a009c00950047008e008c00880099004700990096009b0088009b008c008b004702e700470079008c0088009900
47009000950095008c00990047009700900095009000960095> reverse rotated → Rear outer
<009700900095009000960095004700990096009b0088009b008c008b004702e700470079008c008800990047008800950095009c0093009c009a0047008e008c00880099004700990096009b0088009b008c008b004702e70047006d009900960095009b00
47008800950095009c0093009c009a0047008e008c00880099> rotated → Front pinion
<00990096009b0088009b008c008b004702e70047006d009900960095009b0047009a009c00950047008e008c0088009900470099008c009d008c0099009a008c004700990096009b0088009b008c008b004702e70047007c0095008b008c0099008b009900
90009d008c0047004f007c0056006b00500047008f009c0089> reverse rotated
Input shaft rotated → Overdrive clutch (OD/C) retainer rotated
Input shaft rotated → 35R clutch rotated -
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Power flow ▶
Description 35R C OD C 26 B UD B LR B O.W.C
P.N●