2003 SSANGYONG MUSSO ECO mode

AUTOMATIC TRANSMISSION 5A-31
K-Line
The K-line is typically used for obtaining diagnostic information from the TCU. A computer with a special interface is
connected to the TCU and all current faults, stored faults, runtime parameters are then available. The stored faultcodes can also be cleared.
The K-line can be used for vehicle coding at the manufacturer’ s plant or in the workshop. This allows for one TCU
design to be used over different vehicle models. 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. HYDRAULIC CONTROL SYSTEM
The hydraulic controls are located in the valve body, pump body and main case.The valve body contains the following:
Manual valve,
Three shift valves,
Sequence valve,
solenoid supply pressure regulator valve,
line pressure control valve,
clutch apply regulator valve,
band apply regulator valve,
S1 to S6, and
Reverse lockout valve.
The pump body contains the following:
Primary regulator valve for line pressure,
converter clutch regulator valve,
converter clutch control valve,
S7,and
C1 bias valve.
The main case contains the following:
B1R exhaust valve
The hydraulic control system schematic is shown at figure 3.7.
All upshifts are accomplished by simultaneously switching on a shift valve(s), switching VPS pressure to the band
and/or clutch regulator valve, and then sending the VPS a ramped current. The shift is completed by switching the
regulators off and at the same time causing the VPS to reach maximum . pressure. All downshifts are accomplished
by switching VPS pressure to the band and/or clutch regulator valve and sending a ramped current to the VPS. The
shift is completed by simultaneously switching the regulators off, switching the shift valves and at the same timecausing the VPS to return to stand-by pressure.
The primary regulator valve is located in the pump cover and supplies four line pressures; high and low for forward
gears, and high and low for reverse. This pressure has no effect on shift quality and merely provides static clutch
capacity during steady state operation. Low pressure can be obtained by activating an On/off solenoid with high line pressure being the default mode.
Torque converter lock-up is initiated by toggling the converter clutch control valve with an On/off solenoid. The actual apply and release of the clutch is regulated by the VPS via the converter clutch regulator valve. As an additionalsafety feature, the lock-up is hydraulically disabled in first and second gear by the bias valve which only supplies oilto the lock-up solenoid when C1 is applied in third and fourth gears. This prevents the vehicle from being renderedimmobile in the unlikely event of S7 becoming stuck.
The solenoid supply valve provides reference pressure for all the solenoids.

5A-60 AUTOMATIC TRANSMISSIONDIAGNOSIS
DIAGNOSTIC SYSTEM Recommended T est Equipment and Procedure
The test equipment is designed to be used with the control modules in all vehicles. The components used in the transmission application are: Multi Function Tester, and
Appropriate vehicle for testing.
Multi Function Tester (MFT)
The MFT is programmed with the special vehicle diagnostic software that allows selection of the unit under test.
The program allows the proper communication to the Transmission Control Unit (TCU).
It then requests information from the user via a menu system to select the required set up.
Examples are viewing codes, clearing error codes, and real-time operation. Set up and operation instructions are detailed in the user manual.
This equipment can be used by trained personnel such as technicians and mechanics to diagnose electronic and
wiring problems relating to the vehicle transmission. Information that is available includes engine and road (shaft)
speed, transmission oil temperature, throttle position, solenoid/gear status and gear lever position. Current andstored faults detected by the electronics are also available.
TCU Pin Description The TCU pin descriptions are listed in table 6.1.1. The wiring loom pins are shown in figure 6.1.1
Pin
No. 1 2 3 4 5 6 7 8Identification
Common Ground Do not use Mode Indicator Lamp -‘ Winter ’
Gear Position ‘Park ’
LampGear Position ‘Reverse ’
LampGear Position ‘Neutral ’
LampDo not useEngine Speed Input
Sensor (-Ve) Type
GND -
OP OP OP OP
-
IP Description
Main power ground (or the module. Connects
directly to the battery negative terminal. Indicates ‘WINTER ’ mode shift schedule is se-
lected.
Drives the jewel in the instrument cluster to in-dicate ‘PARK ’ gear lever position.
Drives the jewel in the instrument cluster to in- dicate ‘REVERSE ’ gear lever position.
Drives the jewel in the instrument cluster to in- dicate ‘NEUTRAL ’ gear lever position.
Flywheel/Ring gear pulses to indicate engine speed.
4WD
(Diesel)
O O




4WD
(Gas)
O O O






Table 6.1.1 - TCU Pin Description

5A-64 AUTOMATIC TRANSMISSION
Default Transmission Operating Modes
The TCU relies on accurate information from its inputs and complete control of its outputs to effectively control the
transmission. To ensure that it has both valid inputs and functioning outputs, the TCU carries out both hardware and
software fault detection routines. The TCU will respond to any faults detected by adopting the operating modes which
are detailed below.
The following symptoms of faults are the most obvious results of each fault under ‘normal ’ conditions.
There is always the possibility that a fault may not be detected. If undetected fault conditions are present, the
operation of the transmission is difficult to predict.
1 Throttle Fault
All shifts will occur as if a nominal throttle (approx. 44%) were applied for shift scheduling.
All shifts will be firm as full throttle and hence high engine torque is assumed.
The torque converter will be unlocked at all times.
All downshifts initiated by the shift lever will occur as though they were ‘automatic ’ shifts. That is the engine
braking effect will not occur until near the end of the shift.
Line pressure will always stay high (solenoid 6 OFF) to cope with assumed high throttle/torque.
If a fault is undetected, the percent throttle is most likely to be interpreted as higher than actual, resulting in late
upshifts, early downshifts, firm shifting and a harsh 3-1 shift when stopping.
2 Throttle Not Learnt Fault
The transmission operates from default throttle calibration values which results in the evaluation of the throttle being
higher (more open) than it is. There(ore at zero throttle settings, the transmission may calculate that sufficient throttle
opening is present to justify high line pressure and switch solenoid 6 to OFF. Other symptoms are:
a. late upshifts and
b. lock-up maintained at zero throttle when the vehicle speed is sufficiently high.
3 Engine Speed Fault All shifts will be firm because an engine speed corresponding to peak engine torques is assumed.
If a fault is undetected, the engine speed is likely to be interpreted as stalled resulting in soft shifting possibly with an end of shift bump.
4 Vehicle Speed Sensor Fault
All shifts will be controlled by the shift lever with skip downshifts disabled and downshifts only allowed if the
engine speed is low. Fourth gear will be inhibited.
The torque converter will be unlocked at all times.
If a fault is undetected, the vehicle is likely to be interpreted as being stationary resulting in first gear operation at all
times. Note that speedometer transducer faults are likely to cause the vehicle ’s speedometer to become inoperative.
5 Gear Lever Fault (Inhibitor/PRNDL Switch) The gear lever is assumed to be in the Drive position.
The transmission is limited to 2nd,3rd, and R gears only.
The rear band will apply at all times when the lever is shifted to P, R or N. (B2 inhibition and reverse lockout
protection is disabled.)
The torque converter will be unlocked at all times.
Manually (gear lever) initiated downshifts will not be available.
If a fault is undetected, the gear lever position is likely to be interpreted as being higher than actual. Where Park is the
highest position and Manual 1 is the lowest, the result being the availability of higher gears than selected by the gear
lever.

AUTOMATIC TRANSMISSION 5A-65
If the gear lever is incorrectly adjusted, the transmission may shift gears on bumpy road surfaces.
6 Transmission Oil Temperature Sensing FaultAll shifts will be firm until the transmission has warmed up, because a high transmission oil temperature is
assumed.
If a fault is undetected, the temperature is likely to be evaluated as being lower than actual, resulting in softer shifts with ‘end bump ’ (very firm feel at the end of the shift).
7 Mode Setting Fault All shifts will occur as if the mode is set to ‘NORMAL ’ .
The mode indicator will always be off indicating that ‘NORMAL ’ mode is selected.
The mode indicator will not respond to changes in switch setting.
If a fault is undetected, the mode as indicated by the mode indicator is not likely to respond to the mode switch.
8 Battery Voltage Sensing Fault
If the battery voltage is low then shifts to first gear are inhibited.9 the battery voltage is high (>16.5V) then the transmission goes into limp home (LHM) mode.
If a fault is undetected, the transmission is likely to incorrectly evaluate an ON/OFF solenoid fault resulting in limp home mode (LHM) operation.
9 ON/OFF Solenoid Fault (Solenoids 1,2,3 and 4)
The transmission adopts its limp home mode (LHM) operation, described above. However, if solenoid 1 is faulty then
the fourth gear LHM strategy will be adopted independent of vehicle speed.
If a fault is undetected, the operation of the transmission is dependent on which solenoid is actually faulty. The
characteristics for different solenoid fault conditions are listed in table 6.1.2.
10 ON/OFF Solenoid Fault (Solenoids 6,7)
If solenoid 6 is found faulty it is always disabled resulting in high line pressure being applied continuously.
If solenoid 7 is found faulty it is disabled resulting in the transmission being locked always.The transmission does not go into LHM.
11 Variable Pressure Solenoid Fault The transmission adopts its LHM operation.
If a fault is undetected, the transmission shift feel is likely to be poor for all shifts.
12 Software Fault
The transmission adopts the third gear LHM strategy of operation, independent of vehicle speed. The operation of
the TCU under this condition is difficult to predict. Its operation may be erratic.
If a fault is undetected, the operation of the TCU is likely to be erratic.
13 Power Supply Fault
The transmission adopts the third gear LHM strategy of operation, independent of vehicle speed. If there is an
intermittent power supply connection, the TCU will power-up in fourth gear and then shift to the appropriate gear to
satisfy the conditions present. The power supply is not monitored for fault evaluation.
All faults except for solenoid faults can be recovered without having to turn the TCU off and back on. However, in
general the recovery requires that no faults are present for a period of time (approx. 3 or 30 seconds). Recovery from
a fault will not clear the fault from the keep alive memory
14 Transmission Sump Temperature Exceeding 135°C
The converter lockup clutch will be applied at lower speeds, causing a shudder through the vehicle.
The mode indicator will flash in some vehicles.
These faults can be due to the transmission oil overheating or due to an incorrect signal received from the temperature
sensor.

5A-68 AUTOMATIC TRANSMISSION
Description / Cause
The signal from the mode switch is unreliable.
This fault is caused by too many changes in the mode input signal
over a period of time. Typical causes would be an intermittent connec
tion in the switch or wiring or an intermittent short to ground in thewiring.
The data link between the TCU and the engine management module
is found to be unreliable because the checksum, or the data received, did not match the correct checksum.
This could be caused by an open circuit, short circuit to ground or aloose connection in the link wire itself.
Each solenoid in turn is switched off if it was energised, or switched on
if it was not energised by a very small 100 ms pulse. This pulse is too
short for the solenoid to react so transmission operation is not af fected.
The solenoid feedback voltage is measured before the 100 ms pulse
and again during the pulse. If the difference is outside the acceptablelimits the relevant fault messages are set.
Typical causes would be an open circuit in the wiring to or within the
solenoid, or a short circuit to ground in the wiring to, from or within thesolenoid in question.If several of these fault codes are presents check the wiring or
connectors that are common to the selected solenoids, especially the earth connections.
The state of the solenoid feedback voltage is outside acceptablelimits but the faulty solenoid could not be isolated.The current to solenoid 5 was outside acceptable limits.
This fault results from a mismatch between the current set point for
solenoid 5 and the current measured by the feedback within the TCU.
Typical causes would be an open circuit or short circuit to ground in
the wiring to, from or within the solenoid. It is also possible that there
has been a fault in the solenoid output circuit. If this is the case
however, the fault should be continually present.
The closed throttle position has not been learnt. This fault may be caused by the transmission not having reached normaloperating temperature or the engine idle speed being incorrect.The TCU will learn the closed throttle position automatically when the transmission is brought to normal operating temperature and the engine is allowed to idle in Drive with the‘ base idle ’ correctly set and the air conditioner (if fitted)
switched off.
Condition
Mode Switch Input Fault(Power/Economy Mode) Data Output Link Fault On/off Solenoid Fault (Solenoid 1,2,3,4,6,7) Solenoid 5 Fault
(Variable Pre ssure
Solenoid) Throttle Not LearntSolenoid
9
10 11 12 13

AUTOMATIC TRANSMISSION 5A-69
MECHANICAL TESTS
In Vehicle Transmission Checks
Carry out the following tests before removing the transmission. See Checking Transmission Fluid Level, Section 7.2.1.
Check that the transmission oil is not burnt (colour and smell are correct).
Ensure that the transmission is not in limp home mode (LHM).
Check that the battery terminals and the earth connections are not corroded or loose.
Check the engine stall speed is within the handbook value.
Check that the cooler flow is not restricted.
Check that all electrical plug connections are tight.
Carry out a road test to confirm the symptoms, if necessary.
Inspect the oil, ensure that there are no metal or other contaminants in the oil pan.
Diagnosing Oil Leaks
Determine the source of oil leaks by firstly cleaning down the affected area, then driving the vehicle. Inspect the seals to confirm the source of the leak. To determine the source of a rear servo oil leak, raise the vehicle on a hoist, then carry out a reverse stall.
To determine the source of a front servo leak, raise the vehicle on a hoist, then run the vehicle in second gear.
Troubleshooting Charts The troubleshooting charts are set out as follows: Table 6.2.1 Drive Faults,
Table 6.2.2 Faulty Shift Patterns.
Table 6.2.3 Shift Quality Faults.
Table 6.2.4 After Teardown Faults.
Table 6.2.1 - Drive Faults
Action
Check the fluid level. Top up as necessary. Inspect and clean C1/C2 feed. Reinstall/renew the ‘z’ link.
Remove, clean and re-install the PRV.
Inspect and replace as necessary.
Inspect and replace as necessary.
Inspect and replace as necessary.
Check servo adjustment or replace rear band
as necessary.
Check for failure in C3, C3 hub or C1/C2 cylin-
der. Repair as necessary.
Inspect and clean PRV.
Inspect and replace pump gears as necessary.
Inspect and repair as necessary.
Possible Cause
Insufficient auto transmission fluid.
Blocked feed in C1/C2 cylinder.
‘Z’ link displaced.
Primal regulator valve (PRV) jammed open.Overdrive shaft or input shaft seal ringsfailed. 3-4 or 1-2 one way clutch (OWC) installed backwards or failed.C2 piston broken or cracked.
Rear band or servo faulty.
Failure in C3, C3 hub or C1/C2 cylinder.Jammed primary regulator valve (PRV). Damaged/broken pump gears. Dislodged output shaft snap ring.Symptom
No Drive in D No Drive in ReverseNo engine braking
in Manual 1 Engine braking in Manual 1 is OKNo drive in Driveand Reverse

AUTOMATIC TRANSMISSION 5A-127
Torque Converter and Housing Assembly
To assemble the torque converter and housing assembly, proceed as follows.
1. Locate the torque converter housing on the transmissionmain case.
2. Install and tighten the securing bolts to specification. NoticeAll the hardware must be correctly installed and torqued to specification.
3. Fit the converter ensuring that the tangs are engaged in the pump gear. Ensure that the tangs do not contact thepump seal.
Figure 8.1 - Torque Specifications
Torque Specifications
Torque converter housing to case Extension housing to case Rear servo coverPan to caseInhibitor switch to caseCooler connectors
Transmission filler plug Output flange lock nut (RWD models)Centre support to caseCam plate to case (parking pawl)
Valve body to case Upper valve body to lower valve bodyON/OFF solenoid retainers
Variable pressure solenoid retainerLine pressure plug Detent spring Pump cover to casePump cover plate to pump coverPump to pump adaptorPump cover plate to crescent Adaptor to case N

m
54 - 68 54 - 6825 - 35 4 - 6
2.3 - 3.4 30 - 3530 - 35
100 - 110
20 - 27 16 - 228 - 13
11 - 16 8 - 12 8 - 12
4 - 7
20 - 2224 - 3413 - 1624 - 27 13 - 16 25 - 35

5D1-8 TRANSFER CASE (PART TIME 4408) SELF-DIAGNOSIS TEST
Test Procedure
1. Connect the scanner harness connector to the enginecompartment diagnosis socket.
2. Turn the ignition switch to "ON" position.
3. Select "Electronic control vehicle diagnosis" from the function selection display and press "Enter".
4. Select "Musso" from vehicle model selection display and press "Enter".
5. Select "TCCU" from control system selection display and press "Enter".
6. Select "TCCU Part Time" from TCCU diagnosis selection display. Notice
Check sensor valve output display if necessary.
7 . Select "Self-diagnosis" from diagnosis items selection display.
8. Turn the ignition switch to "OFF" position and press "ENTER". Turn the ignition swtich to "ON" position again and press "ENTER".
9. Determine fault code and check the defective component.
Notice Refer to self-diagnosis list.