PRECAUTIONS
AT-9
< SERVICE INFORMATION >
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• Before assembly, apply a coat of recommended ATF to all parts. Apply petroleum jelly to protect O-rings and
seals, or hold bearings and washers in place during assembly. Do not use grease.
• Extreme care should be taken to avoid damage to O-rings, seals and gaskets when assembling.
• Clean or replace ATF cooler if excessive foreign material is found in oil pan or clogging strainer. Refer to
Refer to .
• After overhaul, refill the A/T with new ATF.
• When the A/T drain plug is removed, only some of the fluid is drained. Old A/T fluid will remain in torque con-
verter and ATF cooling system.
Always follow the procedures under “Changing A/T Fluid” in the AT section when changing A/T fluid. Refer to
MA-22, "
Changing A/T Fluid", MA-22, "Checking A/T Fluid".
Service Notice or PrecautionINFOID:0000000001703155
ATF COOLER SERVICE
If A/T fluid contains frictional material (clutches, bands, etc.), or if an A/T is repaired, overhauled, or replaced,
inspect and clean the A/T oil cooler mounted in the radiator or replace the radiator. Flush cooler lines using
cleaning solvent and compressed air after repair. Check Service Bulletins for latest A/T oil cooler cleaning pro-
cedure. For radiator replacement, refer to Refer to CO-11
.
TORQUE CONVERTER SERVICE
The torque converter should be replaced under any of the following conditions:
• External leaks in the hub weld area.
• Converter hub is scored or damaged.
• Converter pilot is broken, damaged or fits poorly into crankshaft.
• Steel particles are found after flushing the cooler and cooler lines.
• Pump is damaged or steel particles are found in the converter.
• Vehicle has TCC shudder and/or no TCC apply. Replace only after all hydraulic and electrical diagnoses
have been made. (Converter clutch material may be glazed.)
• Converter is contaminated with engine coolant containing antifreeze.
• Internal malfunction of stator roller clutch.
• Heavy clutch debris due to overheating (blue converter).
• Steel particles or clutch lining material found in fluid filter or on magnet when no internal parts in unit are
worn or damaged — indicates that lining material came from converter.
The torque converter should not be replaced if:
• The fluid has an odor, is discolored, and there is no evidence of metal or clutch facing particles.
• The threads in one or more of the converter bolt holes are damaged.
• A/T malfunction did not display evidence of damaged or worn internal parts, steel particles or clutch plate lin-
ing material in unit and inside the fluid filter.
• Vehicle has been exposed to high mileage (only). The exception may be where the torque converter clutch
dampener plate lining has seen excess wear by vehicles operated in heavy and/or constant traffic, such as
taxi, delivery or police use.
OBD-II SELF-DIAGNOSIS
• A/T self-diagnosis is performed by the TCM in combination with the ECM. The results can be read through
the blinking pattern of the OD OFF indicator lamp or the malfunction indicator lamp (MIL). Refer to the table
on AT-78, "
Diagnosis Procedure without CONSULT-III" for the indicator used to display each self-diagnostic
result.
• The self-diagnostic results indicated by the MIL are automatically stored in both the ECM and TCM memo-
ries.
Always perform the procedure “HOW TO ERASE DTC” on AT-36, "
OBD-II Diagnostic Trouble Code
(DTC)" to complete the repair and avoid unnecessary blinking of the MIL.
• The following self-diagnostic items can be detected using ECM self-diagnostic results mode* only when the
OD OFF indicator lamp does not indicate any malfunctions.
-PNP switch
- A/T 1st, 2nd, 3rd, or 4th gear function
*: For details of OBD-II, refer to AT- 3 6
.
•Certain systems and components, especially those related to OBD, may use a new style slide-lock-
ing type harness connector.
For description and how to disconnect, refer to PG-65
.
AT-16
< SERVICE INFORMATION >
A/T FLUID
5. Run engine at idle speed for 5 minutes.
6. Check A/T fluid level and condition. Refer to MA-22, "
Checking A/T Fluid".
A/T Fluid Cooler CleaningINFOID:0000000001703160
Whenever the A/T is repaired, overhauled, or replaced, the A/T fluid cooler mounted in the radiator must be
inspected and cleaned.
Metal debris and friction material, if present, can become trapped in the A/T fluid cooler. This debris can con-
taminate the newly serviced A/T or, in severe cases, can block or restrict the flow of A/T fluid. In either case,
malfunction of the newly serviced A/T may result.
Debris, if present, may build up as A/T fluid enters the cooler inlet. It will be necessary to back flush the cooler
through the cooler outlet in order to flush out any built up debris.
A/T FLUID COOLER CLEANING PROCEDURE
1. Identify the A/T inlet and outlet fluid cooler hoses.
2. Position an oil pan under the A/T inlet and outlet fluid cooler
hoses.
3. Disconnect the A/T fluid cooler inlet and outlet rubber hoses
from the steel cooler tubes or bypass valve.
NOTE:
Replace the cooler hoses if rubber material from the hose
remains on the tube fitting.
4. Allow any A/T fluid that remains in the cooler hoses to drain into
the oil pan.
5. Insert the extension adapter hose of a can of Transmission
Cooler Cleaner (Nissan P/N 999MP-AM006) into the cooler out-
let hose.
CAUTION:
• Wear safety glasses and rubber gloves when spraying the
Transmission Cooler Cleaner.
• Spray Transmission Cooler Cleaner only with adequate
ventilation.
• Avoid contact with eyes and skin.
• Do not breath vapors or spray mist.
6. Hold the hose and can as high as possible and spray Transmis-
sion Cooler Cleaner in a continuous stream into the cooler outlet
hose until A/T fluid flows out of the cooler inlet hose for 5 seconds.
7. Insert the tip of an air gun into the end of the cooler outlet hose.
8. Wrap a shop rag around the air gun tip and end of cooler outlet
hose.
9. Blow compressed air regulated to 5 - 9 kg/cm
2 (70 - 130 psi) through the cooler outlet hose for 10 seconds
to force out any remaining A/T fluid.
10. Repeat steps 5 through 9 three additional times.
11. Position an oil pan under the banjo bolts that connect the A/T fluid cooler steel lines to the A/T.
12. Remove the banjo bolts.Fluid grade and capacity: Refer to MA-10
.
SCIA5628E
SCIA5629E
SCIA5630E
AT-34
< SERVICE INFORMATION >
A/T CONTROL SYSTEM
Control Valve
INFOID:0000000001703170
FUNCTION OF CONTROL VALVES
Centrifugal Cancel MechanismINFOID:0000000001703171
FUNCTION
The centrifugal cancel mechanism is a mechanism to cancel the centrifugal hydraulic pressure instead of the
conventional check balls. It cancels the centrifugal hydraulic pressure which is generated as high clutch drum
rotates, and it allows for preventing high clutch from dragging and for providing stable high clutch piston press-
ing force in all revolution speeds.
STRUCTURE/OPERATION
Valve name Function
Pressure regulator valve, plug and sleeve
plugRegulates oil discharged from the oil pump to provide optimum line pressure for all driving
conditions.
Pressure modifier valve and sleeve Used as a signal supplementary valve to the pressure regulator valve. Regulates pres-
sure-modifier pressure (signal pressure) which controls optimum line pressure for all driv-
ing conditions.
Pilot valve Regulates line pressure to maintain a constant pilot pressure level which controls lock-up
mechanism, overrun clutch, shift timing.
Accumulator control valve Regulates accumulator back-pressure to pressure suited to driving conditions.
Manual valve Directs line pressure to oil circuits corresponding to select positions.
Hydraulic pressure drains when the shift lever is in Neutral.
Shift valve A Simultaneously switches three oil circuits using output pressure of shift solenoid valve A
to meet driving conditions (vehicle speed, throttle opening, etc.).
Provides automatic downshifting and upshifting (1st → 2nd → 3rd → 4th gears/4th → 3rd
→ 2nd → 1st gears) in combination with shift valve B.
Shift valve B Simultaneously switches two oil circuits using output pressure of shift solenoid valve B in
relation to driving conditions (vehicle speed, throttle opening, etc.).
Provides automatic downshifting and upshifting (1st → 2nd → 3rd → 4th gears/4th → 3rd
→ 2nd → 1st gears) in combination with shift valve A.
Overrun clutch control valve Switches hydraulic circuits to prevent engagement of the overrun clutch simultaneously
with application of the brake band in D
4. (Interlocking occurs if the overrun clutch engages
during D
4.)
1st reducing valve Reduces low & reverse brake pressure to dampen engine-brake shock when downshift-
ing from the 1st position 1
2 to 11.
Overrun clutch reducing valve Reduces oil pressure directed to the overrun clutch and prevents engine-brake shock.
In the 1st and 2nd positions, line pressure acts on the overrun clutch reducing valve to
increase the pressure-regulating point, with resultant engine brake capability.
Torque converter relief valve Prevents an excessive rise in torque converter pressure.
Torque converter clutch control valve, plug
and sleeveActivates or inactivates the lock-up function.
Also provides smooth lock-up through transient application and release of the lock-up
system.
1-2 accumulator valve and piston Lessens the shock find when the 2nd gear band servo contracts, and provides smooth
shifting.
3-2 timing valve Switches the pace that oil pressure is released depending on vehicle speed; maximizes
the high clutch release timing, and allows for soft downshifting.
Shuttle valve Determines if the overrun clutch solenoid valve should control the 3-2 timing valve or the
overrun clutch control valve and switches between the two.
Cooler check valve At low speeds and with a small load when a little heat is generated, saves the volume of
cooler flow, and stores the oil pressure for lock-up.
AT-40
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
●: Solenoid ON
×: Solenoid OFF
–: Non-standard condition
Line Pressure Solenoid Valve
If non-standard solenoid signal is sent to TCM, line pressure solenoid valve is turned OFF to achieve maxi-
mum oil pressure.
Torque Converter Clutch Solenoid Valve
If non-standard solenoid signal is sent to TCM, torque converter clutch solenoid valve is turned OFF to release
lock-up.
Overrun Clutch Solenoid Valve
If non-standard solenoid signal is sent to TCM, overrun clutch solenoid valve is turned OFF to engage overrun
clutch. This will result in more effective engine brake during deceleration.
How to Perform Trouble Diagnosis for Quick and Accurate RepairINFOID:0000000001703179
INTRODUCTION
The TCM receives a signal from the vehicle speed sensor, accelera-
tor pedal position sensor or PNP switch and provides shift control or
lock-up control via A/T solenoid valves.
The TCM also communicates with the ECM by means of a signal
sent from sensing elements used with the OBD-related parts of the
A/T system for malfunction-diagnostic purposes. The TCM is capa-
ble of diagnosing malfunctioning parts while the ECM can store mal-
functions in its memory.
Input and output signals must always be correct and stable in the
operation of the A/T system. The A/T system must be in good oper-
ating condition and be free of valve seizure, solenoid valve malfunc-
tion, etc.
It is much more difficult to diagnose a malfunction that occurs intermittently rather than continuously. Most
intermittent malfunctions are caused by poor electric connections or improper wiring. In this case, careful
checking of suspected circuits may help prevent the replacement of good parts.
Shift positionNormalMalfunction in solenoid
valve AMalfunction in solenoid
valve BMalfunction in solenoid
valves A and B
A B Gear A B Gear A B Gear A B Gear
“D” position●●1st –●→×
3rd ●→×–
3rd ––
3rd ×●2nd –●→× ×–––
××3rd – x×–––
●×4th – x●→×–––
“2” position●●1st –●→×●→×–––
×●2nd –●→× ×–––
××3rd – x×–––
“1” position●●1st –●→×●→×–––
×●2nd –●→× ×–––
××3rd – x×–––
SAT631IA
AT-48
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
Inspections Before Trouble Diagnosis
INFOID:0000000001703182
A/T FLUID CHECK
Fluid Leakage and Fluid Level Check
Check fluid leakage and check the fluid level. Refer to MA-22, "Checking A/T Fluid".
Fluid Condition Check
Check the A/T fluid condition.
STALL TEST
Stall Test Procedure
1. Check ATF and engine oil levels. If necessary, add ATF and
engine oil.
2. Drive vehicle for approximately 10 minutes or until ATF and
engine oil reach operating temperature.
3. Set parking brake and block wheels.
4. Install a tachometer where it can be seen by driver during test.
•It is good practice to mark the point of specified engine
rpm on indicator.
5. Start engine, apply foot brake, and place selector lever in “D”
position.
Fluid status Conceivable Cause Required Operation
Varnished (viscous
varnish state)Clutch, brake
scorchedReplace the ATF and check the A/T
main unit and the vehicle for mal-
functions (wire harnesses, cooler
pipes, etc.)
Milky white or
cloudyWater in the ATFReplace the ATF and check for plac-
es where water is getting in.
Large amount of
metal powder mixed
inUnusual wear of
sliding parts within
A/TReplace the ATF and check for im-
proper operation of the A/T.
SAT638A
ATF operating temperature: 50 - 80°C (122 - 176°F)
SAT647B
SAT513G
SAT775B
TROUBLE DIAGNOSIS
AT-51
< SERVICE INFORMATION >
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Location of line pressure test ports are shown in the figure.
•Always replace pressure plugs as they are self-sealing bolts.
Line Pressure Test Procedure
1. Check ATF and engine oil levels. If necessary, add ATF or
engine oil.
2. Drive vehicle for approx. 10 minutes or until engine oil and ATF
reach operating temperature.
3. Install oil pressure gauge to corresponding line pressure test
port.
4. Set parking brake and block wheels.
5. Start engine and measure line pressure at idle and stall speed.
CAUTION:
• Keep the brake pedal pressed all the way down during
measurement.
• When measuring the line pressure at the stall speed, refer
to "STALL TEST".
SCIA7187E
ATF operating temperature: 50 - 80°C (122 -176°F)
SAT647B
SCIA6528J
SAT513G
SAT493G
AT-52
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
Line Pressure
Judgement of Line Pressure Test
Road TestINFOID:0000000001703183
DESCRIPTION
• The purpose of the test is to determine overall performance of A/T
and analyze causes of malfunctions.
• The road test consists of the following three parts:
1. Check before engine is started. Refer to AT- 5 3
.
2. Check at idle. Refer to AT- 5 3
.
3. Cruise test
• Inspection all the item from Part 1 to Part 3. Refer to AT- 5 5
,
AT- 5 8
and AT- 5 9 .
Engine speedLine pressure [kPa (kg/cm
2 , psi)]
D, 2nd and 1st positions R position
Idle speed 500 (5.1, 73) 778 (7.9, 113)
Stall speed 1,173 (12.0, 170) 1,825 (18.6, 265)
Judgement Suspected parts
At idleLine pressure is low in all positions. • Oil pump wear
• Control piston damage
• Pressure regulator valve or plug sticking
• Spring for pressure regulator valve damaged
• Fluid pressure leakage between oil strainer and pressure regulator valve
• Clogged strainer
Line pressure is low in particular posi-
tion.• Fluid pressure leakage between manual valve and particular clutch
• For example, line pressure is:
− Low in “R” and “1” positions, but
− Normal in “D”, and “2” positions.
Therefore, fluid leakage exists at or around low and reverse brake circuit.
Refer to AT- 1 9 , "
Shift Mechanism".
Line pressure is high. • Accelerator pedal position signal malfunction
• A/T fluid temperature sensor damaged
• Line pressure solenoid valve sticking
• Short circuit of line pressure solenoid valve circuit
• Pressure modifier valve sticking
• Pressure regulator valve or plug sticking
• Open in dropping resistor circuit
At stall
speedLine pressure is low. • Accelerator pedal position signal malfunction
• Line pressure solenoid valve sticking
• Short circuit of line pressure solenoid valve circuit
• Pressure regulator valve or plug sticking
• Pressure modifier valve sticking
• Pilot valve sticking
SAT786A
TROUBLE DIAGNOSIS
AT-55
< SERVICE INFORMATION >
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1. Apply foot brake.
2. Move selector lever to “R” position.
Is there large shock when changing from
“N” to “R” position?
YES >> • Mark the box on the AT-40, "How to Perform Trouble
Diagnosis for Quick and Accurate Repair" .
•Go to AT-180, "
Large Shock "N" → "R" Position" .
• Continue “Road Test”.
NO >> GO TO 6.
6.CHECK VEHICLE MOVE
Release foot brake for several seconds.
Does vehicle creep backward when foot brake is released?
YES >> GO TO 7.
NO >> • Mark the box on the AT-40, "
How to Perform Trouble
Diagnosis for Quick and Accurate Repair" .
•Go to AT-181, "
Vehicle Does Not Creep Backward in
"R" Position" .
• Continue “Road Test”.
7.CHECK VEHICLE MOVE
Move selector lever to “D”, “2” and “1” positions and check if vehicle
creeps forward.
Does vehicle creep forward in all three positions?
YES >> Go to AT-55, "Cruise Test - Part 1" .
NO >> • Mark the box on the AT-40, "
How to Perform Trouble
Diagnosis for Quick and Accurate Repair" .
•Go to AT-182, "
Vehicle Does Not Creep Forward in
"D", "2" or "1" Position" .
• Continue “Road Test”.
Cruise Test - Part 1INFOID:0000000001703186
1.CHECK STARTING GEAR (D1 ) POSITION
1. Drive vehicle for approximately 10 minutes to warm engine oil and ATF up to operating temperature.
2. Park vehicle on flat surface.
SAT797A
SAT772B
SAT799A
SAT773B
ATF operating temperature: 50 - 80°C (122 - 176°F)