2011 NISSAN LATIO clutch

A/T CONTROL SYSTEMAT-35
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Lock-up Control System Diagram
Lock-up Released
In the lock-up released state, the torque converter clutch control valve is set into the unlocked state by drain-
ing the torque converter clutch piston applying pressure and the torque converter clutch piston release pres-
sure is generated.
In this way, the torque converter clutch piston is not coupled.
Lock-up Applied
In the lock-up applied state, the torque converter clutch
control valve is set into the locked state by generating
the torque converter clutch piston applying pressure and t he torque converter clutch piston release pressure is
drained.
In this way, the torque converter clutch piston is pressed and coupled.
SMOOTH LOCK-UP CONTROL
When shifting from the lock-up released state to the lock-up applied state, the current output to the torque con-
verter clutch solenoid is controlled with the TCM. In this way, when shifting to the lock-up applied state, the
torque converter clutch is temporarily set to the half-clutched state to reduce the shock.
Half-clutched State
The current output from the TCM to the torque converte r clutch solenoid is varied to steadily increase the
torque converter clutch solenoid pressure.
In this way, the lock-up applying pressure gradually rises and while the torque converter clutch piston is put
into half-clutched status, the torque converter clutch piston applying pressure is increased and the coupling is
completed smoothly.
Engine Brake Control (Overrun Clutch Control)INFOID:0000000005928081
Forward one-way clutch is used to reduce shifting shoc ks in downshifting operations. This clutch transmits
engine torque to the wheels. However, drive force fr om the wheels is not transmitted to the engine because
the one-way clutch rotates idle. This means the engine brake is not effective.
The overrun clutch operates when the engine brake is needed.
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Revision: May 2010 2011 Versa

AT-36
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A/T CONTROL SYSTEM
OVERRUN CLUTCH OPERATING CONDITIONS
OVERRUN CLUTCH SOLENOID VALVE CONTROL
The overrun clutch solenoid valve is operated by an ON-OFF signal
transmitted by the TCM to provide overrun clutch control (engine
brake control).
When this solenoid valve is “ON”, the pilot pressure drain port
closes. When it is “OFF”, the drain port opens.
During the solenoid valve “ON” pilot pressure is applied to the end
face of the overrun clutch control valve.
OVERRUN CLUTCH CONTROL VALVE OPERATION
When the solenoid valve is “ON”, pilot pressure is applied to the
overrun clutch control valve. This pushes up the overrun clutch con-
trol valve. The line pressure is t hen shut off so that the clutch does
not engage. Only in “1” position, however, 1 range pressure is
applied to overrun clutch control valve, resulting in valve moving
downward and clutch engaged.
When the solenoid valve is “OFF”, pilot pressure is not generated. At
this point, the overrun clutch control valve moves downward by
spring force. As a result, overrun clutch operation pressure is pro-
vided by the overrun clutch reducing valve. At overrun clutch reduc-
ing valve in “D” position, the hydraulic pressure is reduced to a level
that balances the spring force. This is sent to overrun clutch control
valve and becomes the operating pressure of overrun clutch which is
engaged at all times. In “2” position and “1” position, overrun clutch
reducing valve is pushed down by 2 range pressure. Line pressure is
directly sent to overrun clutch control valve and becomes the operat-
ing pressure of overrun clutch which is engaged at all times.
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Revision: May 2010 2011 Versa

A/T CONTROL SYSTEMAT-37
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Control ValveINFOID:0000000005928082
FUNCTION OF CONTROL VALVES
Centrifugal Cancel MechanismINFOID:0000000005928083
FUNCTION
The centrifugal cancel mechanism is a mechanism to c ancel the centrifugal hydraulic pressure instead of the
conventional check balls. It cancels the centrifugal hy draulic 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
plug Regulates 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 (1GR → 2GR → 3GR → 4GR/4GR →
3GR → 2GR → 1GR) 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 (1GR → 2GR → 3GR → 4GR/4GR →
3GR → 2GR → 1GR) 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 sleeve Activates 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 2GR band servo contracts, and provides smooth shift-
ing.
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.
Revision: May 2010 2011 Versa

AT-38
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A/T CONTROL SYSTEM
A centrifugal cancel housing is provided to cancel the clutch housing pressure. The centrifugal cancel housing
is always filled with ATF from the dedicated fluid passage of oil pump.
When Clutch Pressure Is Not Applied
As high clutch drum rotates, a centrifugal force applies to the remaining ATF in clutch housing to push high
clutch piston. However, on the other hand, the centrifugal force also applies to ATF filled in centrifugal cancel
housing, resulting in a force that pushes high clutch piston back. Consequently the high clutch piston does not
move because both forces cancel each other, and thus high clutch is prevented from dragging.
When Clutch Pressure Is Applied
Clutch pressure that applies to clutch housing overcomes the fluid pressure and spring force of the opposing
centrifugal housing to push high clutch piston, and high clutch is engaged. At this time, the centrifugal force
caused by the revolution speed of high clutch drum has no impact any more since the centrifugal force that
applies to the clutch pressure of clutch housing is canceled by the centrifugal force that applies to centrifugal
cancel housing. As a result, high clutch piston pressing force is always stable in all revolution speeds, and
thus smooth shifting characteristics are achieved.
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Revision: May 2010 2011 Versa

TROUBLE DIAGNOSISAT-43
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z : Solenoid ON
× : Solenoid OFF
–: Non-standard condition
Line Pressure Solenoid Valve
If non-standard solenoid signal is sent to TCM, line pre ssure 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 conv erter clutch solenoid valve is turned OFF to release
lock-up.
Overrun Clutch Solenoid Valve
If non-standard solenoid signal is sent to TCM, overr un 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:0000000005928091
INTRODUCTION
The TCM receives a signal from the vehicle speed sensor, accelera-
tor pedal position sensor or transmission range 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 wit h 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. T he 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 c onnections or improper wiring. In this case, careful
checking of suspected circuits may hel p prevent the replacement of good parts.
Shift positionNormal
Malfunction in solenoid
valve A Malfunction in solenoid
valve B Malfunction in solenoid
valves A and B
A BGearABGearABGearABGear
“D” position zz
1st –z→×
3rd z
→× –
3rd ––
3rd
×
z2nd – z→× ×–––
×× 3rd – x ×–––
z ×4th – x z→× –––
“2” position zz
1st –z→× z→× –––
× z2nd – z→× ×–––
×× 3rd – x ×–––
“1” position zz
1st –z→× z→× –––
× z2nd – z→× ×–––
×× 3rd – x ×–––
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Revision: May 2010 2011 Versa

AT-46
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TROUBLE DIAGNOSIS
Diagnostic Worksheet Chart
Customer name MR./MS Model & YearVIN
Trans. model EngineMileage
Incident Date Manuf. DateIn Service Date
Frequency † Continuous † Intermittent ( times a day)
Symptoms † Vehicle does not move. ( † Any position † Particular position)
† No up-shift ( † 1st → 2nd † 2nd → 3rd † 3rd → 4th)
† No down-shift ( † 4th → 3rd † 3rd → 2nd† 2nd → 1st)
† Lock-up malfunction
† Shift point too high or too low.
† Shift shock or slip ( † N → D † Lock-up † Any drive position)
† Noise or vibration
† No kick down
† No pattern select
† Others
()
Malfunction indicator lamp (MIL) † Continuously lit † Not lit
1. † Read the Fail-safe and listen to customer complaints. AT- 4 2,
"Information
from
customer"
2. † Check A/T fluid AT- 1 7
† Leakage (Follow specified procedure)
† Fluid condition
† Fluid level
3. † Perform “STALL TEST” and “LINE PRESSURE TEST”. AT- 5 1
†“STALL TEST”— Mark possible damaged components/others.
† Torque converter one-way clutch
† Reverse clutch
† Forward clutch
† Overrun clutch
† Forward one-way clutch †
Low & reverse brake
† Low one-way clutch
† Engine
† Line pressure is low
† Clutches and brakes except high clutch and
brake band are OK
† “LINE PRESSURE TEST”— Suspected parts:
Revision: May 2010 2011 Versa

TROUBLE DIAGNOSISAT-47
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4. † Perform “Road Test”. AT- 5 5
4-1. “Check Before Engine is Started” AT- 5 6
†AT- 1 8 0 , "OD OFF Indicator Lamp Does Not Come On"
† Perform self-diagnosis. Enter checks for detected items. AT- 7 7 , AT- 8 2 .
† CAN COMM CIRCUIT AT- 8 7
.
† TRANSMISSION RANGE SWITCH A AT- 9 0
.
† TRANSMISSION FLUID TEMPERATURE SENSOR A AT- 9 5
.
† OUTPUT SPEED SENSOR AT- 1 0 0
.
† ENGINE SPEED AT- 1 0 5
.
† 1GR INCORRECT RATIO AT- 1 0 9
† 2GR INCORRECT RATIO AT- 11 2 .
† 3GR INCORRECT RATIO AT- 11 5
.
† 4GR INCORRECT RATIO AT- 11 8
.
† TORQUE CONVERTER AT- 1 2 3
.
† TORQUE CONVERTER AT- 1 2 8
.
† PRESSURE CONTROL SOLENOID A AT- 1 3 3
.
† SHIFT SOLENOID A AT- 1 3 8
.
† SHIFT SOLENOID B AT- 1 4 3
.
† OVERRUN CLUTCH SOLENOID AT- 1 4 8
.
† VEHICLE SPEED SIGNAL AT- 1 5 3
.
† BATT/FLUID TEMP SEN AT- 1 5 6
.
† INPUT SPEED SENSOR A AT- 1 6 2
.
† CONTROL UNIT (RAM), CONTROL UNIT (ROM) AT- 1 6 7
.
† MAIN POWER SUPPLY AND GROUND CIRCUIT AT- 1 6 8
.
4-2. “Check at Idle” AT- 5 6
†AT- 1 8 2 , "Engine Cannot Be Started in "P" and "N" Position" .
† AT- 1 8 3 , "
In "P" Position, Vehicle Moves Forward or Backward When Pushed" .
† AT- 1 8 3 , "
In "N" Position, Vehicle Moves" .
† AT- 1 8 4 , "
Large Shock "N" → "R" Position" .
† AT- 1 8 5 , "
Vehicle Does Not Creep Backward in "R" Position" .
† AT- 1 8 6 , "
Vehicle Does Not Creep Forward in "D", "2" or "1" Position" .
Revision: May 2010 2011 Versa

AT-48
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TROUBLE DIAGNOSIS
4. 4-3. “Cruise Test”AT- 5 8
Part 1
†AT- 1 8 7 , "
Vehicle Cannot Be Started from D1" .
† AT- 1 8 9 , "
A/T Does Not Shift: D1→ D2or Does Not Kickdown: D4→ D2" .
† AT- 1 9 0 , "
A/T Does Not Shift: D2→ D3" .
† AT- 1 9 2 , "
A/T Does Not Shift: D3→ D4" .
† AT- 1 9 3 , "
A/T Does Not Perform Lock-up" .
† AT- 1 9 4 , "
A/T Does Not Hold Lock-up Condition" .
† AT- 1 9 5 , "
Lock-up Is Not Released" .
† AT- 1 9 6 , "
Engine Speed Does Not Return to Idle (Light Braking D4→ D3)" .
Part 2 AT- 6 1
†AT- 1 8 7 , "Vehicle Cannot Be Started from D1" .
† AT- 1 8 9 , "
A/T Does Not Shift: D1→ D2or Does Not Kickdown: D4→ D2" .
† AT- 1 9 0 , "
A/T Does Not Shift: D2→ D3" .
† AT- 1 9 2 , "
A/T Does Not Shift: D3→ D4" .
Part 3 AT- 6 2
†AT- 1 9 7 , "A/T Does Not Shift: D4→ D3, When OD OFF" .
† AT- 1 9 8 , "
A/T Does Not Shift: D3→ 22, When Selector Lever "D" → "2" Position" .
† AT- 1 9 9 , "
A/T Does Not Shift: 22→ 11, When Selector Lever "2" → "1" Position" .
† AT- 2 0 1 , "
Vehicle Does Not Decelerate by Engine Brake" .
† Perform self-diagnosis. Enter checks for detected items. AT- 7 7
, AT- 8 2 .
† CAN COMM CIRCUIT AT- 8 7
.
† TRANSMISSION RANGE SWITCH A AT- 9 0
.
† TRANSMISSION FLUID TEMPERATURE SENSOR A AT- 9 5
.
† OUTPUT SPEED SENSOR AT- 1 0 0
.
† ENGINE SPEED AT- 1 0 5
.
† 1GR INCORRECT RATIO AT- 1 0 9
† 2GR INCORRECT RATIO AT- 11 2 .
† 3GR INCORRECT RATIO AT- 11 5
.
† 4GR INCORRECT RATIO AT- 11 8
.
† TORQUE CONVERTER AT-123
.
† TORQUE CONVERTER AT-128
.
† PRESSURE CONTROL SOLENOID A AT- 1 3 3
.
† SHIFT SOLENOID A AT- 1 3 8
.
† SHIFT SOLENOID B AT- 1 4 3
.
† OVERRUN CLUTCH SOLENOID AT- 1 4 8
.
† VEHICLE SPEED SIGNAL AT- 1 5 3
.
† BATT/FLUID TEMP SEN AT-156
.
† INPUT SPEED SENSOR A AT- 1 6 2
.
† CONTROL UNIT (RAM), CONTROL UNIT (ROM) AT-167
.
† MAIN POWER SUPPLY AND GROUND CIRCUIT AT- 1 6 8
.
5. † For self-diagnosis NG items, inspect each component. Repair or replace the damaged parts. AT- 7 7
,
AT- 8 2
6. † Perform “Road Test”. AT- 5 5
7.† Perform the Diagnostic Procedures for all remaining items marked NG. Repair or replace the damaged parts.
Refer to the Symptom Chart when you perform the procedures. (The chart also shows some other possible symp-
toms and the component inspection orders.) AT- 6 5
8.
† Erase DTC from TCM and ECM memories. AT- 3 9,
AT- 8 2
Revision: May 2010 2011 Versa