lock NISSAN VERSA 2006 Workshop Service User Guide

AT-22
A/T CONTROL SYSTEM
Revision: June 20062007 Versa
CLUTCH AND BAND CHART

*1: Operates when OD OFF. (OD OFF indicator lamp is on.)

*2: Oil pressure is applied to both 2nd “apply” side and 3rd “release” side of band servo piston. However, brake band does not con-
tract because oil pressure area on the “release” side is greater than that on the “apply” side.

*3: Oil pressure is applied to 4th “apply” side on condition *2 above, and brake band contracts.

*4: A/T will not shift to 4th when OD OFF. (OD OFF indicator lamp is on.)

: Operates.

A: Operates when throttle opening is less than specification**, activating engine brake.

B: Operates during “progressive” acceleration.

C: Operates but does not affect power transmission.

D: Operates when throttle opening is less than specification**, but does not affect engine brake.
–**: Overrun clutch remains in engaged condition when throttle opening is less than 1/16. Shift posi-
tionR/C
5H/C
6F/C
15O/C
17Band servo
F/O.C
16L/O.C
18L&R/B
19Lock-
upRemarks
2nd
apply3rd
release4th
apply
PPA R K
POSITION
RREVERSE
POSITION
NNEUTRAL
POSITION
D*4 1st *1D B B
2nd *1A BAutomatic
shift
3rd *1A *2C C B
*11 ⇔ 2 ⇔ 3
⇔ 4
4th C *3C C
21stBB
Automatic
shift
1 ⇔ 2 ⇐ 3 2ndB
3rd *2C C B
11stBB
Locks (held
stationary)
in 1st speed
1 ⇐ 2 ⇐ 3 2ndB
3rd *2C C B

A/T CONTROL SYSTEM
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POWER TRANSMISSION
“N” and “P” Positions

“N” position
Power from the input shaft is not transmitted to the output shaft because the clutches do not operate.

“P” position
Similar to the “N” position, the clutches do not operate. The parking pawl engages with the parking gear to
mechanically hold the output shaft so that the power train is locked.
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AT-24
A/T CONTROL SYSTEM
Revision: June 20062007 Versa
“11 ” Position

Forward clutch

Forward one-way clutch

Overrun clutch

Low & reverse brakeAs overrun clutch engages, rear internal gear is locked by the operation of low and
reverse brake.
This is different from that of D
1 and 21 .
Engine brake Overrun clutch always engages, therefore engine brake can be obtained when deceler-
ating.
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A/T CONTROL SYSTEM
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“D1 ” and “21 ” Positions
*: Overrun clutch remains in engaged condition when throttle opening is less than 1/16.

Forward one-way clutch

Forward clutch

Low one-way clutchRear internal gear is locked to rotate counterclockwise because of the functioning of these three
clutches.
Overrun clutch
engagement conditions
(Engine brake)D
1 : OD OFF (OD OFF indicator lamp is on) and throttle opening is less than specification*
2
1 : Always engaged
At D
1 and 21 positions, engine brake is not activated due to free turning of low one- way clutch.
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AT-30
A/T CONTROL SYSTEM
Revision: June 20062007 Versa
TCM FunctionUCS005MC
The function of the TCM is to:

Receive input signals sent from various switches and sensors.

Determine required line pressure, shifting point, lock-up operation, and engine brake operation.

Send required output signals to the respective solenoids.
CONTROL SYSTEM OUTLINE
The automatic transaxle senses vehicle operating conditions through various sensors or signals. It always
controls the optimum shift position and reduces shifting and lock-up shocks.
CONTROL SYSTEM DIAGRAM
SWITCHES & SENSORS


TCM


ACTUATORS
PNP switch
Accelerator pedal position signal
Closed throttle position signal
Wide open throttle position signal
Engine speed signal
A/T fluid temperature sensor
Revolution sensor
Turbine revolution sensor (Power
train revolution sensor)
Vehicle speed sensor
Overdrive control switch signal
Stop lamp switch signalShift control
Line pressure control
Lock-up control
Overrun clutch control
Fail-safe control
Self-diagnosis
CONSULT-II communication line
controlShift solenoid valve A
Shift solenoid valve B
Overrun clutch solenoid valve
Torque converter clutch solenoid
valve
Line pressure solenoid valve
OD OFF indicator lamp
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A/T CONTROL SYSTEM
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CAN CommunicationUCS005M D
SYSTEM DESCRIPTION
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only. For details, refer to LAN-47,
"CAN System Specification Chart" .
Input/Output Signal of TCMUCS005M E
*1: Spare for vehicle speed sensor·A/T (revolution sensor)
*2: Spare for accelerator pedal position signal
*3: If these input and output signals are different, the TCM triggers the fail-safe function.
*4: Used as a condition for starting self-diagnostics; if self-diagnosis are not started, it is judged that there is some kind of error.
*5: Input by CAN communications.
*6: Output by CAN communications.Control itemLine
pressure
controlVehicle
speed
controlShift
controlLock-up
controlEngine
brake
controlFail-safe
functionSelf-diag-
nostics
function
InputAccelerator pedal position signal
(*5)XXXXX(*3) XX
Vehicle speed sensor·A/T
(Revolution sensor)XXXXX(*3) XX
Vehicle speed sensor·MTR (*1) X (*1) X (*1) X (*1) X X
Closed throttle position signal
(*5)(*2) X(*2) XXX(*4) X
Wide open throttle position signal
(*5)(*2) X (*2) X (*4) X
Turbine revolution sensor (Power
train revolution sensor)XX X XX
Engine speed signal X X X X
PNP switch X X X X X (*3) X (*4) X
Stop lamp switch signal
(*5)XX (*4) X
A/T fluid temperature sensors
(*5)XXXX XX
Overdrive control switch signal
(*5)XXXX (*4) X
TCM power supply voltage signal X X X X
Out-
putShift solenoid valve A/B X (*3) X X
Line pressure solenoid X (*3) X X
Torque converter clutch solenoid
valveX(*3) XX
Overrun clutch solenoid valve X X (*3) X X
OD OFF indicator lamp
(*6)XX

AT-34
A/T CONTROL SYSTEM
Revision: June 20062007 Versa
CONTROL OF SHIFT VALVES A AND B
Pilot pressure generated by the operation of shift solenoid valves A and B is applied to the end face of shift
valves A and B.
The figure above shows the operation of shift valve B. When the shift solenoid valve is “ON”, pilot pressure
applied to the end face of the shift valve overcomes spring force, moving the valve upward.
Lock-up ControlUCS005MH
The torque converter clutch piston in the torque converter is locked to eliminate torque converter slip and to
increase power transmission efficiency. The solenoid valve is controlled by an ON-OFF duty signal sent from
the TCM. The signal is converted to an oil pressure signal which controls the torque converter clutch piston.
CONDITIONS FOR LOCK-UP OPERATION
When vehicle is driven in 3rd and 4th gear positions, vehicle speed and throttle opening are detected. If the
detected values fall within the lock-up zone memorized in the TCM, lock-up is performed.
TORQUE CONVERTER CLUTCH SOLENOID VALVE CONTROL
Lock-up Control System Diagram
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OD ON OFF
Selector lever “D” position
Gear position D
4D3
Vehicle speed sensor More than set value
Accelerator pedal position signal Less than set opening
Closed throttle position signal OFF
A/T fluid temperature sensor More than 40°C (104°F)
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A/T CONTROL SYSTEM
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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 the 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 converter 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)UCS005M I
Forward one-way clutch is used to reduce shifting shocks in downshifting operations. This clutch transmits
engine torque to the wheels. However, drive force from 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.
OVERRUN CLUTCH OPERATING CONDITIONS
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A/T CONTROL SYSTEM
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Control ValveUCS005MJ
FUNCTION OF CONTROL VALVES
Valve name Function
Pressure regulator valve, plug and sleeve
plugRegulates oil discharged from the oil pump to provide optimum line pressure for all driv-
ing 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
driving 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-44
TROUBLE DIAGNOSIS
Revision: June 20062007 Versa
Shift Solenoid Valve A and B
If non-standard solenoid signal is sent to TCM, use of certain gears is limited. Refer to chart shown below.

: 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.
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×–––