2003 SSANGYONG MUSSO manual transmission

AUTOMATIC TRANSMISSION 5A-57
POWER FLOW - DRIVE 4 (OVERDRIVE)
In Drive 4 (Overdrive), transmission drive is via the input shaft to the forward clutch cylinder. The elements of the transmission function as follows :
The C1 clutch is applied to drive the planet carrier clockwise.
The B1 band is applied to hold the reverse sun gear stationary.
As the planet carrier tuns, the long pinion ‘walks ’ around the stationary reverse sun gear and rotates around its
axis driving the internal ring gear and output shaft in a clockwise or forward direction at a speed faster than the input shaft i.e. in overdrive ratio.
The forward sun gear is also driven faster than the input shaft and overruns the 3-4 OWC.
The C2 clutch is engaged to reduce the speed differential across the 3-4 OWC.
Control
To maintain this arrangement in the steady state solenoids and valves are activated as follows: Solenoid S1 is switched On. S2 is switched Off.
With S1 switched On the 3-4 shift valve is held in the fourth gear position by line 500 pressure on the small end
of the valve.
With S2 switched Off the 2-3 shift valve is held in the fourth gear position by line 500 pressure on the large end of the valve.
The 1-2 shift valve is held in the fourth gear position by S2 oil pressure.
2nd oil (line pressure) from the 1-2 shift valve is directed to the band apply regulator valve, and to the 2-3 shift
valve.
The band apply regulator valve supplies 2nd oil (regulated to line pressure multiplied by the valve ratio) to the
band apply feed (BAF) circuit.
Band apply feed oil is directed to: - the outer apply area of the front servo- the inner apply area of the front servo piston via the 3-4 shift valve
- the 1-2 shift valve to provide an exhaust port when the transmission is shifted to first gear
2nd oil at the 2-3 shift valve is directed to the 3rd oil circuit.
3rd oil from the 2-3 shift valve is directed to the clutch apply regulator valve, and to the 4-3 Sequence Valve.
The clutch apply regulator valve supplies oil (regulated to line 500 pressure multiplied by the valve ratio) to the
clutch apply feed (CAF) circuit.
The CAF oil is directed to:- the C1 clutch- the C1 bias valve- the 4-3 sequence valve
Drive oil (line pressure) from the manual valve engages the C2 clutch
Refer to figure 5.8 and table 5.9.
Table 5.9 - Engaged Elements - Drive 4 (Overdrive)
Gear State
Drive 4 (Overdrive) C1
X C2
X C3
- C4
- B1
X B2
- 1-2
OWC - 3-4
OWC X LU
CLUTCH -
ELEMENTS ENGAGED

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.

5A-66 AUTOMATIC TRANSMISSION
Diagnostic Trouble Messages The diagnostic trouble messages generated by the TCU and their possible causes are listed in table 6.1.3.
Table 6.1.2 - Transmission Operations for On/Off Solenoid Faults
Transmission Operation
First gear instead of second and fourth gear instead of third. This results in a 1
4 shift as the vehicle accelerates from rest.
Second gear instead of first and third gear instead of fourth.This results in second gear starts.
Fourth gear instead of first and third gear instead of second.This results in fourth gear starts.
Second gear instead of third and first gear instead of fourth. This results in a 1
2 then 2
1 (overrun) downshift as the vehicle
accelerates from rest. The following shifts become poor:1
3, 1
4, 2
1 2
3, 2
4, 4
2, 4
1.
The following shifts become poor: 3
4, 4
3, 3
2.
There may be slippage in the gears during torque converter locking. The following shifts become poor:1
2, 1
3, 1
4, 2
3, 2
4, 3
1, 3
2 (All Including Manual), 3
4,
4
1,4
3.
The following shifts become poor:2
4, 3
2.
There may be slippage in the gears during torque converter locking.Line pressure always high.Line pressure always low thus resulting in risk of slippage in gears.
Torque converter always unlocked.
Torque converter always locked in 3rd and 4th gears, causing thevehicle to shudder at lower speeds,
Condition
Always ON Always OFF Always OFF Always ON Always OFF Always ON Always OFF Always ON Always OFF Always ON Always OFFAlways ONSolenoid 1 2 34 6 7

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

5A-70 AUTOMATIC TRANSMISSION
Action
Inspect S1. Repair or replace as necessary.
Check for 12 Volts applied to S1 at all times orfor wiring fault.
Inspect S1. Repair or replace as necessary.
Check for 12 Volts applied to S1 at all times or for wiring fault.
Inspect S2. Repair or replace as necessary.
Check for open circuit or wiring fault.
Inspect S2. Repair or replace as necessary. Check for open circuit or wiring fault.
Inspect and adjust as necessary.
Inspect and repair as necessary.
Inspect and replace or refit as necessary. Inspect ‘O’ ring. Refit or replace as nec essary.
Inspect the 2-3 shift valve. Repair or replace
as necessary.
Inspect C1 clutch. Repair or replace as neces-
sary.
Inspect ball. Refit or replace as necessary. Inspect C4. Repair C4 or replace C4 wave plate
as necessary.
Inspect rear band adjustment. Adjust as nec-
essary.
Inspect ball- Refit or replace as necessary. Inspect ’0’ring. Refit or replace as necessary.
Inspect C4 and C4 wave plate. Repair or re-
place as necessary.Inspect inhibitor switch. Repair or replace as necessary.
Inspect the 1-2 shift valve.
Repair or replace as necessaryInspect inhibitor switch.Repair or replace as necessary.
Inspect the 2-3 shift valve.Repair or replace as necessary.
Possible Cause
S1 always OFF. S1 always ON.
S2 always OFF. S2 always ON. B1 failed. Loose band adjustment.Front servo piston or seal failed.S1/S2 ball misplaced, Smaller ’0’ring on front servo piston failed
or missing. 2-3 shift valve jammed.C1 clutch failed or slipping in 3rd and 4th.(Gives 1st in 3rd and 2nd in 4th.) Over-run clutch (OC)/low ball misplaced. C4 failed or C4 wave plate broken. Rear band slipping when hot. Reverse/Low-1st ball misplaced. Rear servo inner ‘O’ ring missing.
C4 failed or C4 wave plate broken.
Inhibitor switch faulty. 1-2 shift valve jammed.
Inhibitor switch fault, 1-2 only. 2-3 shift valve jammed.Symptom
2-3 shift only
(no 4th or 1st)
1-4 shift only1-3-4 (Delayed1-2shift)4-3 shift only 1-2-Neutral
(1st over run)1-3 shift only 1-3-4 only 1-2-1 only No manual 4-3,3-2
or 2 - 1 No manual 1st 1st gear only or
2nd,3rd, and 4thonly 1st and 2nd only or 1st, 3rd and 4th
only

5A-72 AUTOMATIC TRANSMISSION
Action
Drain and fill with specified ATF.
Check that S5 is fitted correctly, or replace S5.
Inspect band apply and clutch apply regulator
springs. Refit or replace as necessary.
Inspect the ball. Refit or replace as necessary.
Inspect C4 clutch. Replace or repair as neces-
sary.
Check the alignment. ]Realign as necessary.
Inspect wave plate. Replace as necessary.
Inspect S5 and replace as necessary.
Inspect the damper spring and replace as nec-
essary.
Replace spring as necessary.
Check the clearance and adjust as necessary.
Inspect C4. Repair or replace as necessary.
Inspect piston. Repair or replace as necessary.
Inspect and adjust band as necessary. Replace the plug. Replace the spring.Replace the spring/plug.Refit the ball.
Inspect the clutch. Repair the clutch as neces-
sary. Inspect and clean C1 feed.Replace the piston.
Inspect and replace the sealing rings and/or
shaft as necessary. Inspect and replace the ball.
Inspect and replace the sealing rings and/or
shaft as necessary.
Inspect and repair the C1 clutch as necessary.Refit the valve. Replace the ball.
Possible Cause
Incorrect auto transmission fluid (ATF).
S5 faulty won, or incorrectly fitted.Band apply and clutch apply regulatorsprings misplaced. Over-run clutch (OC)/Low-1st ball misplaced.C4 clutch worn or burnt. C4 wave plate not lined up with the holes in the piston. C4 wave plate failed.S5 worn.S5 damper spring broken. Front servo belleville spring broken. Incorrect C4 pack clearance.Damaged C4 clutch.Cracked C2 piston (leaking into C4).Incorrect band adjustment Front servo plastic plug missing B1R spring broken.B1R spring/plug left out.C1/B1R ball misplaced.C1 clutch damaged. Restriction in C1 feed. C1 piston check ball jammed.
Overdrive or input shaft sealing rings dam-aged. C1/B1R ball misplaced.
Overdrive or input shaft sealing rings dam-aged.C1 clutch damaged.4-3 sequence valve in backwards. Low-1st check ball misplaced.Symptom
All Shifts Firm Manual 4-3-2-1 is soft delayed or
missing Firm 1-2 Hot
4th Tied up
Tied up on 2-3Flare on 2-3 Slips in 4th Flare on 4-3, Flare on 3-2Firm Manual low
shift-high line press.

5A-74 AUTOMATIC TRANSMISSION
Action
Inspect, repair C2 and adjust the linkage as neces-
sary. Repair C2. Inspect, repair or replace S6 as neces-
sary.Repair C2. Inspect, replace the sealing rings and/
or shaft as necessary. Repair C2. Inspect, repair or replace the C2 piston
as necessary.
Inspect C4 and repair as necessary.Inspect and adjust the C4 pack clearance as nec-
essary. Repair C4. Inspect and replace the wave plate as
necessary.Repair C4. Inspect and realign the wave plate as
necessary.Repair C4. Inspect and realign the sealing rings
and/or shaft as necessary. Repair C4. Inspect and refit the OWC as neces-
sary.Repair C4. Inspect and replace the C2 piston as
necessary.
Repair C4. Inspect and refit the ball as necessary.Inspect and repair B1 and replace the spring as
necessary.Replace sealing ring.
Repair B1. Refit the ball as necessary. Inspect and repair C1 and replace the spring.Repair C1. Inspect and replace the sealing tongs
and/or shaft as necessary.Repair C1. Inspect and replace the C1 piston as
necessary. Repair C1. Inspect and refit the capsule as neces-
sary.Repair C1. Inspect and refit the valve as neces-
sary. Repair C1. Inspect and replace the ball as neces-
sary.
Inspect and adjust the band as necessary.
Inspect and refit the ball as necessary.Inspect and replace the ‘O’ ring as necessary.
Inspect and refit the valve as necessary.Inspect and replace the ‘O’ ring as necessary.
Inspect and refit the valve as necessary.
Possible Cause
T-bar linkage out of adjustment.
56 foiled - stuck low. Overdrive/output shaft sealing rings damaged. C2 piston cracked. Incorrect C4 pack clearance. C4 wave plate broken.
C4 wave plate not lined up properly.Overdrive or output shaft sealing rings dam- aged. 3-4 one way clutch (OWC) in backwards. C2 piston cracked. Over-run clutch (OC)/low-1st ball misplaced. B1R spring broken. Input shaft sealing ring cut. C1/B1R ball misplaced. B1R spring left out.Overdrive or input shaft sealing rings damaged. C1 piston cracked. Ball capsule jammed. 4-3 sequence valve in backwards. Clutch apply feed (CAF)/B1R ball left out. Rear band incorrectly adjusted or damaged. Reverse-low/first ball misplaced.Input shaft ‘O’ ring missing or damaged.
Converter clutch regulator valve in backwards.Input shaft ‘O’ ring missing or damaged.
C1 bias valve in backwards.
Symptom
C2 burnt C4 burnt B1 burnt C1 burnt Slips in reverse - no manual 1st Firm converter
lock or unlockNo lock up at lightthrottle
Table 6.2.4 - After Teardown Faults