5A-50 AUTOMATIC TRANSMISSION
POWER FLOW - MANUAL 1
In Manual 1, transmission drive is via the input shaft
to the forward clutch cylinder. The elements of the
transmission function as follows :
lThe C2 clutch is engaged to drive the forward sun gear, via the 3-4 OWC.
lThe B2 band is engaged to hold the planetary gear carrier stationary.
lThe forward sun gear drives the short pinion anti-clockwise.
lThe short pinion drives the long pinion clockwise.
lThe long pinion rotating about its axis drives the internal ring gear and the output shaft in a clockwise or
forward direction.
lThe C4 clutch provides engine braking through the 3-4 OWC on overrun.
Control
To maintain this arrangement in the steady state solenoids and valves are activated as follows:
lSolenoids S1 and S2 are switched ON.
lThe 1-2,2-3, and 34 shift valves are held in their first gear positions by line 500 pressure.
lDrive (line pressure) oil from the manual valve engages the C2 clutch.
lLo-1st (line pressure) oil is routed through the 1-2 shift valve to the C4 clutch, and to the inner apply area of
the rear servo piston for B2 band application.
Refer to figure 5.3 and table 5.4.
Table 5.4 - Engaged Elements - Manual 1
Gear State
Manual 1C1
-C2
XC3
-C4
XB1
-B2
X1-2
OWC
-3-4
OWC
XLU
CLUTCH
- ELEMENTS ENGAGED
AUTOMATIC TRANSMISSION 5A-51
POWER FLOW - DRIVE 1
In Drive 1, transmission drive is via the input shaft to the forward clutch cylinder. The elements of the transmission
function as follows :
lThe C2 clutch is engaged to drive the forward sun gear.
lThe forward sun gear drives the short pinion anti-clockwise.
lThe short pinion drives the long pinion clockwise.
lThe 1-2 OWC prevents the planetary gear carrier from rotating under reaction force and the long pinion
rotates on its axis driving the internal ring gear and output shaft in a clockwise or forward direction.
lThere is no engine braking on overrun.
Control
To maintain this arrangement in the steady state solenoids and valves are activated as follows:
lSolenoids S1 and S2 are switched On.
lThe 1-2, 2-3, and 3-4 shift valves are held in their first gear positions by line 500 pressure.
lDrive (line pressure) oil from the manual valve engages the C2 clutch.
Refer to figure 5.4 and table 5.5
Table 5.5 - Engaged Elements - Drive 1
Gear State
Drive 1C1
-C2
XC3
-C4
-B1
-B2
-1-2
OWC
X3-4
OWC
XLU
CLUTCH
- ELEMENTS ENGAGED
5A-52 AUTOMATIC TRANSMISSION
POWER FLOW - DRIVE 2 AND MANUAL 2
In Drive 2 and Manual 2, transmission drive is via the input shaft and forward clutch cylinder. The elements of the
transmission function as follows :
lThe C2 clutch is applied to drive the forward sun gear.
lThe forward sun gear drives the short pinion anti-clockwise.
lThe short pinion drives the long pinion clockwise.
lThe B1 band is applied holding the reverse sun gear stationary therefore the long pinion ‘walks’ around the
reverse sun gear taking the internal ring gear and output shaft with it in a clockwise or forward direction.
lThe C4 clutch is applied to bypass the 3-4 OWC and provide engine braking on overrun.
Control
To maintain this arrangement in the steady state solenoids and valves are activated as follows: Solenoid S1 is
switched Off. S2 is switched On.
lSolonoid S1 is switched Off. S2 is switched On.
lDrive (line pressure) oil from the manual valve engages the C2 clutch.
lWhen S1 switches off , S1 oil pressure, which is derived from line 500 pressure, moves the 3-4 shift valve to
the left. At the same time S1 oil is directed to the 1-2 shift valve which moves the valve to the second gear
position.
l2nd oil (line pressure) from the 1-2 shift valve is directed to the band apply regulator valve, and to the 2-3 shift
valve.
lThe band apply regulator valve supplies 2nd oil (regulated to line pressure multiplied by the valve ratio) to the
band apply feed (BAF) circuit.
lBand apply feed oil is directed to:
- The outer apply area of the front servo
- The 1-2 shift valve to provide an exhaust port when the transmission is shifted to first gear
- The 3-4 shift valve for use when the transmission is shifted into fourth gear
lDrive (line pressure) is routed through the 3-4 shift valve to apply the C4 clutch.
Refer to figure 5.5 and table 5.6.
Table 5.6 - Engaged Elements - Drive 2 and Manual 2
Gear State
Drive 2 and Manual 2C1
-C2
XC3
-C4
XB1
XB2
-1-2
OWC
-3-4
OWC
XLU
CLUTCH
- ELEMENTS ENGAGED
5A-54 AUTOMATIC TRANSMISSION
POWER FLOW - DRIVE 3 AND MANUAL 3
In Drive 3 and Manual 3, transmission drive is via the input shaft to the forward clutch cylinder. The elements of the
transmission function as follows :
lThe C2 clutch is engaged to drive the forward sun gear.
lThe C1 clutch is engaged to drive the planet carrier.
lThe forward sun gear and the planet carrier are driven clockwise at the same speed therefore there is no
relative motion between the sun gear and the pinions.
lThe ring gear and output shaft are driven in a clockwise or forward direction at input shaft speed.
lThe C4 clutch is applied to bypass the 3-4 OWC and provide engine braking on overrun.
Control
To maintain this arrangement in the steady state solenoids and valves are activated as follows:
lSolenoid S1 is switched Off. S2 is switched Off.
lWith S1 and S2 switched Off, the 2-3 and 3-4 shift valves are held in the third gear position by line 500
pressure.
lThe 1-2 shift valve is held in the third gear position by S1-S2 oil pressure.
l2nd oil (line pressure) from the 1-2 shift valve is directed to the band apply regulator valve. and to the 2-3 shift
valve.
lThe band apply regulator valve supplies 2nd oil (regulated to line pressure multiplied by the valve ratio) to the
band apply feed (BAF) circuit.
lBand apply feed oil is directed to:
- The outer apply area of the front servo
- The 1-2 shift valve to provide an exhaust port when the transmission is shifted to first gear
- The 3-4 shift valve for use when the transmission is shifted into fourth gear
l2nd oil at the 2-3 shift valve is directed to the 3rd oil circuit.
l3rd oil from the 2-3 shift valve is directed to the clutch apply regulator valve, and to the 4-3 Sequence Valve.
lThe clutch apply regulator valve supplies oil (regulated to line 500 pressure multiplied by the valve ratio) to the
clutch apply feed (CAF) circuit.
l The CAF oil is directed to:
- The C1 clutch
- The C1 bias valve
- The 4-3 sequence valve
lAt the 4-3 sequence valve the CAF oil becomes band 1 release feed (B1R-F) oil, and is directed through the
3-4 shift valve to the spring end of the 4-3 sequence valve, and to the release side of the front servo piston to
hold band 1 off.
lDrive (line pressure) is routed through the 3-4 shift valve to apply the C4 clutch.
Refer to figure 5.6 and table 5.7.
Table 5.7 - Engaged Elements - Drive 3 and Manual 3
Gear State
Drive 3 and Manual 3C1
XC2
XC3
-C4
XB1
-B2
-1-2
OWC
-3-4
OWC
XLU
CLUTCH
- ELEMENTS ENGAGED
5A-60 AUTOMATIC TRANSMISSION
DIAGNOSIS
DIAGNOSTIC SYSTEM
Recommended Test 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:
lMulti Function Tester, and
lAppropriate 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 and
stored 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’
Lamp
Gear Position ‘Reverse’
Lamp
Gear Position ‘Neutral’
Lamp
Do not use
Engine Speed Input
Sensor (-Ve)Type
GND
-
OP
OP
OP
OP
-
IPDescription
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
l
l l l
l
4WD
(Gas)
O
O
O
l
l l l
l
l
Table 6.1.1 - TCU Pin Description
AUTOMATIC TRANSMISSION 5A-69
MECHANICAL TESTS
In Vehicle Transmission Checks
Carry out the following tests before removing the transmission.
lSee Checking Transmission Fluid Level, Section 7.2.1.
lCheck that the transmission oil is not burnt (colour and smell are correct).
lEnsure that the transmission is not in limp home mode (LHM).
lCheck that the battery terminals and the earth connections are not corroded or loose.
lCheck the engine stall speed is within the handbook value.
lCheck that the cooler flow is not restricted.
lCheck that all electrical plug connections are tight.
lCarry out a road test to confirm the symptoms, if necessary.
lInspect 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.
lTo determine the source of a rear servo oil leak, raise the vehicle on a hoist, then carry out a reverse stall.
lTo 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:
lTable 6.2.1 Drive Faults,
lTable 6.2.2 Faulty Shift Patterns.
lTable 6.2.3 Shift Quality Faults.
lTable 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 rings
failed.
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
Reverse
No engine braking
in Manual 1
Engine braking in
Manual 1 is OK
No drive in Drive
and Reverse
5A-76 AUTOMATIC TRANSMISSION
Action
lCheck cable for open / short.
lCheck connection of other connectors.
lCheck voltage between terminal 27 and 29 of TCU,
- Standard value : 0.2 - 4.7V
lCheck TPS.
lCheck cable for open / short.
lCheck connection of other connectors.
lCheck engine speed sensor.
lCheck resistance between terminal 8 and 24 of TCU (when the
connector is disconnected).
- Standard value : 1 .9 - 0.2 k
W
lCheck cable for open / short.
lCheck connection of other connectors.
lCheck vehicle speed sensor.
lCheck cable for open / short.
lCheck connection of other connectors.
lCheck engine speed sensor.
lCheck inhibitor switch resistance between terminal 34 and 37 of
TCU(when the connector is disconnected).
- Standard value : 1st gear - 4 - 4.4 k
W
2nd gear - 4,8 - 2.2 kW
3rd gear - 3 - 3.4 kW
D gear - 4.5 - 4.g kW
N gear - 6.8 - 7.2 kW
R gear - 10.8 -11.2 kW
P gear - 18.6 - 19 kW
lCheck voltage between terminal 31 and 37 of TCU.
- Standard value : 0-5V(P,R,N,D,L)
lCheck cable for open / short.
lCheck connection of other connectors.
lCheck mode switch.
lCheck condition between terminal 1 and 13 of TCU.
Winter mode :12V, Normal mode : Open status, Power mode : 0V
lCheck cable for open / short.
lCheck connection of other connectors.
lCheck voltage between terminal 32 and 38 of TCU.
- Standard value : 0-5V
lCheck oil temperature sensor.
lCheck cable for open / short.
lCheck connection of other connectors.
lCheck battery condition.
lCheck alternator. Possible Cause
Throttle position sensor
Engine RPM
Vehicle speed
Shift lever
W, E, P mode switch
T/M oil temperature
Battery voltage Symptom
P1702
P1703
P1704
P4705
P1706
P1707
P1708
Self-diagnosis List
AUTOMATIC TRANSMISSION 5A-79
ADJUSTMENTS
HYDRAULIC SYSTEM
The procedures detailed below should be followed in the event that the self test procedure detailed in section 6, or a
defect symptom, indicates that there is a fault in the hydraulic system.
When making adjustments to the transmission, select the appropriate procedures from the following preliminary
checks.
lConduct a transmission fluid test procedure, refer to section 7.2.
lCheck the manual linkage adjustment (refer to the vehicle workshop manual).
lCheck engine idle speed (refer to Section 7.3).
lConduct a stall test (it is outside the scope of this publication to detail this procedure)
lconduct a road test (it is outside the scope of this publication to detail this procedure).
TRANSMISSION FLUID TEST PROCEDURE
Checking Transmission Fluid Level
This procedure is to be used when checking a concern with the fluid level in a vehicle. A low fluid level will result in
gearshift loss or delay if driven when the vehicle is cold.
The vehicle is first checked for transmission diagnostic messages (refer to section 6). If the vehicle has a speedo fault
it is possible for the oil level to be low.
The vehicle is to be test driven to determine if there is an abnormal delay when selecting drive or reverse, or loss of
drive. One symptom of low oil level is a momentary loss of drive when driving the vehicle around a comer. Also when
the transmission fluid level is low, a loss of drive may occur when the transmission oil temperature is low.
If there is no loss of drive when the vehicle is driven warm and a speedo fault is registered, then fluid should be added
to the transmission.
Checking, Adding Fluid and Filling
When adding or changing transmission oil use only Castrol TQ 95 automatic transmission fluid (ATF) or other approved
fluids. The use of incorrect oil will cause the performance and durability of the transmission to be severely degraded.
Do not underfill the transmission. Incorrect tilling may cause damage to the transmission. The fluid level setting
procedure is detailed below.
Notice
When a transmission is at operating temperature hot transmission fluid may come out of the case if the fill plug is
removed. 9 the transmission is at operating temperature allow two hours for cooling prior to removing the plug.
1. If the vehicle is at operating temperature allow the vehicle to cool down for two, but no greater than four hours
before adding transmission fluid (this will allow the transmission to be within the correct temperature
range).
While hot the ATF level is higher and removing the plug may result in oil being expelled from the filler hole. This
will result in the level being low.
2. The transmission selector is to be in Park.
Switch the engine off.
3. Raise the vehicle on a hoist (or leave over a service pit).
4. Clean all dirt from around the service fill plug prior to removing the plug. Remove the oil service fill plug.
Clean the fill plug and check that there is no damage to the ‘O’ ring.
Install the filler pump into the filler hole.
5. Lower the vehicle with the filler pump still connected and partially fill the transmission.
Start the vehicle in Park with the Parking brake and foot brake applied with the engine idling, cycle the transmission
gear selector through all positions, adding ATF until gear application is felt.