AUTOMATIC TRANSMISSION 5A-59
POWER FLOW - DRIVE 4 LOCK UP
In Drive 4 Lock Up, transmission drive is the same as for Drive 4 but with the application of the converter lock up clutch
to provide positive no-slip converter drive.
Control
Control for Drive 4 Lock Up is the same as for Drive 4 with the addition of the converter clutch circuit activated by
solenoid S7.
lWhen S7 is switched On, S7 feed oil to the converter clutch control valve is switched off and allowed to exhaust
through the S7 solenoid. This allows the valve to move to the clutch engage position.
lRegulated apply feed oil, delved from Line 500 oil at the converter clutch regulator valve, is directed by the
converter clutch control valve to the engage side of the converter clutch.
lConverter clutch release oil is exhausted at the converter clutch control valve.
lConverter feed oil is re-routed by the converter clutch control valve directly to the oil cooler and lubrication
circuit.
Refer to figure 5.9 arid table 5.10.
Table 5.10 - Engaged Elements - Drive 4 Lock Up
Gear State
Drive 4 Lock UpC1
XC2
XC3
-C4
-B1
XB2
-1-2
OWC
-3-4
OWC
-LU
CLUTCH
X ELEMENTS ENGAGED
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 Fault
lAll 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
lAll shifts will occur as if the mode is set to ‘NORMAL’.
lThe mode indicator will always be off indicating that ‘NORMAL’ mode is selected.
lThe 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
lThe converter lockup clutch will be applied at lower speeds, causing a shudder through the vehicle.
lThe 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.
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-70 AUTOMATIC TRANSMISSION
Action
Inspect S1. Repair or replace as necessary.
Check for 12 Volts applied to S1 at all times or
for 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 necessary.
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 necessary
Inspect 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 only
1-3-4 (Delayed
1-2shift)
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 4th
only
1st and 2nd only
or 1st, 3rd and 4th
only
AUTOMATIC TRANSMISSION 5A-71
Table 6.2.2 - Faulty Shift Patterns
Action
Inspect inhibitor switch. Repair or replace as
necessary.
Inspect the 3-4 shift valve. Repair or replace
as necessary.
Inspect the release valve. Repair or replace as
necessary.
Inspect S3 or S2. Repair or replace as neces-
sary.
Inspect the regulator valve. Repair or replace
as necessary.
Inspect the ball. Refit or replace as necessary.
Inspect the sealing rings. Refit or replace as
necessary.
Inspect the ‘O’ rings. Refit or replace as neces-
sary.
Inspect the bleed ball. Refit or replace as nec-
essary.
Inspect S1 or S4. Repair or replace as neces-
sary.
Inspect the release valve. Repair or replace as
necessary.
Inspect the band. Adjust as necessary.
Inspect the ‘O’ rings. Refit or replace as neces-
sary.
Inspect S5. Repair or replace as necessary.
Inspect the regulator valve. Repair or replace
as necessary. Possible Cause
Inhibitor switch fault, 1-2-3 only.
3-4 shift valve jammed.
Jammed band 1 release valve.
Faulty S3 or S2 solenoid.
Faulty clutch apply regulator valve.
Missing or damaged clutch apply feed ball.
Damaged input shaft sealing rings.
Damaged C1 piston ‘O’ rings.
Damaged or dislodged C1 piston bleed
ball.
Faulty S1 or S4 solenoid.
Jammed band 1 release valve.
Incorrect front band adjustment.
Damaged front servo piston ‘O’ rings.
Faulty or damaged variable pressure
solenoid (S5).
Faulty band apply regulator valve.Symptom
1st,2nd and 4th
only or 1st,2nd,
and 3rd (tied up in
3rd)
Harsh 2-3 shift
Harsh 3-4 shift
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 regulator
springs 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 2-3
Flare on 2-3
Slips in 4th
Flare on 4-3, Flare
on 3-2
Firm Manual low
shift-high line
press.
AUTOMATIC TRANSMISSION 5A-73
Table 6.2.3 - Shift Quality Faults
Action
Check the resistance. Replace the inhibitor
switch as necessary.
Inspect and replace the sensor as necessary.
Inspect and adjust the band as necessary.
Inspect and replace the’0’rings as necessary.
Inspect, repair or replace S5 as necessary.
Inspect, repair or replace S1 or S4 as neces-
sary.
Inspect, repair or replace the BAR as neces-
sary.
Inspect and repair as necessary.
Inspect and clean CCCV.
Inspect, repair or replace as necessary. Possible Cause
Faulty inhibitor switch.
Faulty throttle position sensor.
Incorrect front band adjustment.
Damaged front servo piston’0’rings.
Faulty or damaged variable pressure so-
lenoid (S5).
Faulty S1 or S4 solenoid.
Faulty band apply regulator valve (BAR).
Misassembled front servo return spring.
Jammed converter clutch control valve
(CCCV).
Faulty solenoid 7.Symptom
Harsh 1-2 shift
stalls when Drive
or Reverse
selected Shudder
on Rolldown
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 unlock
No lock up at light
throttle
Table 6.2.4 - After Teardown Faults