lock NISSAN ALMERA 2001 User Guide

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 drawing above shows the operation of shift valve B. When the
shift solenoid valve is ªONº, pilot pressure applied to the end face
of the shift valve overcomes spring force, moving the valve upward.
LOCK-UP CONTROLNJAT0015S03The torque converter clutch piston in the torque converter is locked
to eliminate torque converter slip 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 pres-
sure signal which controls the torque converter clutch piston.
Conditions for Lock-up OperationNJAT0015S0301When vehicle is driven in 4th gear position, 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.
Overdrive control switch ON OFF
Selector lever ªDº position
Gear position D
4D3
Vehicle speed sensor More than set value
Throttle position sensor Less than set opening
Closed throttle position switch OFF
A/T fluid temperature sensor More than 40ÉC (104ÉF)
SAT010J
Torque Converter Clutch Solenoid Valve ControlNJAT0015S0302The torque converter clutch solenoid valve is controlled by the
TCM. The plunger closes the drain circuit during the ªOFFº period,
and opens the circuit during the ªONº period. If the percentage of
OFF-time increases in one cycle, the pilot pressure drain time is
reduced and pilot pressure remains high.
The torque converter clutch piston is designed to slip to adjust the
ratio of ON-OFF, thereby reducing lock-up shock.
SAT011J
OFF-time INCREASING
¯
Amount of drain DECREASING
¯
Pilot pressure HIGH
¯
Lock-up RELEASING
OVERALL SYSTEM
Control Mechanism (Cont'd)
AT-35

Torque Converter Clutch Control Valve OperationNJAT0015S0303
AAT155A
Lock-up released
The OFF-duration of the torque converter clutch solenoid valve is
long, and pilot pressure is high. The pilot pressure pushes the end
face of the torque converter clutch control valve in combination with
spring force to move the valve to the left. As a result, converter
pressure is applied to chamber A (torque converter clutch piston
release side). Accordingly, the torque converter clutch piston
remains unlocked.
Lock-up applied
When the OFF-duration of the torque converter clutch solenoid
valve is short, pilot pressure drains and becomes low. Accordingly,
the control valve moves to the right by the pilot pressure of the
other circuit and converter pressure. As a result, converter pres-
sure is applied to chamber B, keeping the torque converter clutch
piston applied.
Also smooth lock-up is provided by transient application and
release of the lock-up.
OVERRUN CLUTCH CONTROL (ENGINE BRAKE
CONTROL)
NJAT0015S04Forward one-way clutch is used to reduce shifting shocks in down-
shifting 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 ConditionsNJAT0015S0401
Selector lever position Gear position Throttle opening
ªDº position D
1,D2,D3gear position
Less than 3/16
ª2º position 2
1,22gear position
ª1º position 1
1,12gear position At any position
SAT014J
OVERALL SYSTEM
Control Mechanism (Cont'd)
AT-36

SAT015J
Overrun Clutch Solenoid Valve ControlNJAT0015S0402The overrun clutch solenoid valve is operated by an ON-OFF sig-
nal transmitted by the TCM to provide overrun clutch control
(engine brake control).
When this solenoid valve is ªONº, the pilot pressure drain port
closes. When it is ªOFFº, the drain port opens.
During the solenoid valve ªONº pilot pressure is applied to the end
face of the overrun clutch control valve.
SAT016J
Overrun Clutch Control Valve OperationNJAT0015S0403When the solenoid valve is ªONº, pilot pressure is applied to the
overrun clutch control valve. This pushes up the overrun clutch
control valve. The line pressure is then shut off so that the clutch
does not engage.
When the solenoid valve is ªOFFº, 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. This causes the over-
run clutch to engage.
In the 1 position, the overrun clutch control valve remains pushed
down so that the overrun clutch is engaged at all times.
Control ValveNJAT0016FUNCTION OF CONTROL VALVESNJAT0016S01
Valve name Function
Pressure regulator valve, plug
and sleeveRegulates oil discharged from the oil pump to provide optimum line pressure for all driving
conditions.
Pressure modifier valve and
sleeveUsed as a signal supplementary valve to the pressure regulator valve. Regulates pressure-
modifier pressure (signal pressure) which controls optimum line pressure for all driving condi-
tions.
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 four oil circuits using output pressure of shift solenoid valve A to
meet driving conditions (vehicle speed, throttle opening, etc.).
Provides automatic downshifting and up-shifting (1st®2nd®3rd®4th gears/4th®3rd®
2nd®1st gears) in combination with shift valve B.
OVERALL SYSTEM
Control Mechanism (Cont'd)
AT-37

Valve name Function
Shift valve B Simultaneously switches three oil circuits using output pressure of shift solenoid valve B in
relation to driving conditions (vehicle speed, throttle opening, etc.).
Provides automatic downshifting and up-shifting (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 down-shifting
from the ª1º position 1
2to 11.
Overrun clutch reducing valve Reduces oil pressure directed to the overrun clutch and prevents engine-brake shock.
In ª1º and ª2º 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 Dampens the shock encountered when 2nd gear band servo contracts, and provides smooth
shifting.
3-2 timing valve Switches oil pressure with 3-2 timing valve according to throttle opening.
Shuttle control valve Reduces shock when down-shifting from 3rd to 2nd and regulates overrun clutch.
Cooler check valve Regulates oil pressure which causes lock-up when driving at low speeds.
OVERALL SYSTEM
Control Valve (Cont'd)
AT-38

CONSULT-IINJAT0022After performing ªSELF-DIAGNOSTIC PROCEDURE (WITH CON-
SULT-II)º (AT-39), place check marks for results on the ªDIAGNOS-
TIC WORKSHEETº, AT-71. Reference pages are provided follow-
ing the items.
NOTICE:
1) The CONSULT-II electrically displays shift timing and lock-up
timing (that is, operation timing of each solenoid).
Check for time difference between actual shift timing and the
CONSULT-II display. If the difference is noticeable, mechani-
cal parts (except solenoids, sensors, etc.) may be malfunction-
ing. Check mechanical parts using applicable diagnostic pro-
cedures.
2) Shift schedule (which implies gear position) displayed on
CONSULT-II and that indicated in Service Manual may differ
slightly. This occurs because of the following reasons:
+Actual shift schedule has more or less tolerance or allowance,
+Shift schedule indicated in Service Manual refers to the point
where shifts start, and
+Gear position displayed on CONSULT-II indicates the point
where shifts are completed.
3) Shift solenoid valve ªAº or ªBº is displayed on CONSULT-II at
the start of shifting. Gear position is displayed upon completion
of shifting (which is computed by TCM).
4) Additional CONSULT-II information can be found in the Opera-
tion Manual supplied with the CONSULT-II unit.
SAT580J
SELF-DIAGNOSTIC PROCEDURE (WITH CONSULT-II)NJAT0022S021. Turn on CONSULT-II and touch ªA/Tº for TCM self-diagnosis.
If A/T is not displayed, check TCM power supply and ground
circuit. Refer to AT-118. If result is NG, refer to EL-10, ªPOWER
SUPPLY ROUTINGº.
SAT970J
2. Touch ªSELF-DIAG RESULTSº.
Display shows malfunction experienced since the last erasing
operation.
CONSULT-II performs ªREAL TIME DIAGº.
Also, any malfunction detected while in this mode will be dis-
played at real time.
ON BOARD DIAGNOSTIC
SYSTEM DESCRIPTION
EXCEPT FOR EURO-OBD
CONSULT-II
AT-39

SAT964I
Malfunction Indicator (MI)=NJAT02551. The malfunction indicator will light up when the ignition switch
is turned ON without the engine running. This is for checking
the lamp.
+If the malfunction indicator does not light up, refer to EL-185,
ªWarning Lampsº.
(Or see MI & CONSULT-II in EC section. Refer to EC-74,
ªDescriptionº, ªMalfunction Indicator (MI)º and EC-83, ªCON-
SULT-IIº.)
2. When the engine is started, the malfunction indicator should go
off.
If the lamp remains on, the on board diagnostic system has
detected an emission-related (EURO-OBD) malfunction. For
detail, refer to EC-59, ªON BOARD DIAGNOSTIC SYSTEM
DESCRIPTIONº.
CONSULT-IINJAT0256After performing ªSELF-DIAGNOSTIC PROCEDURE (WITH CON-
SULT-II)º (AT-55), place check marks for results on the ªDIAGNOS-
TIC WORKSHEETº, AT-76. Reference pages are provided follow-
ing the items.
NOTICE:
1) The CONSULT-II electrically displays shift timing and lock-up
timing (that is, operation timing of each solenoid).
Check for time difference between actual shift timing and the
CONSULT-II display. If the difference is noticeable, mechani-
cal parts (except solenoids, sensors, etc.) may be malfunction-
ing. Check mechanical parts using applicable diagnostic pro-
cedures.
2) Shift schedule (which implies gear position) displayed on
CONSULT-II and that indicated in Service Manual may differ
slightly. This occurs because of the following reasons:
+Actual shift schedule has more or less tolerance or allowance,
+Shift schedule indicated in Service Manual refers to the point
where shifts start, and
+Gear position displayed on CONSULT-II indicates the point
where shifts are completed.
3) Shift solenoid valve ªAº or ªBº is displayed on CONSULT-II at
the start of shifting. Gear position is displayed upon completion
of shifting (which is computed by TCM).
4) Additional CONSULT-II information can be found in the Opera-
tion Manual supplied with the CONSULT-II unit.
ON BOARD DIAGNOSTIC SYSTEM
DESCRIPTION
EURO-OBD
Malfunction Indicator (MI)
AT-54

SAT631IA
SAT632I
SEF234G
IntroductionNJAT0023The TCM receives a signal from the vehicle speed sensor, throttle
position sensor or PNP switch and provides shift control or lock-up
control via A/T solenoid valves.
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
operating condition and be free of valve seizure, solenoid valve
malfunction, etc.
It is much more difficult to diagnose a problem that occurs intermit-
tently rather than continuously. Most intermittent problems 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.
A visual check only, may not find the cause of the problems. A road
test with CONSULT-II or a circuit tester connected should be per-
formed. Follow the ªWork Flowº. Refer to AT-73.
Before undertaking actual checks, take a few minutes to talk with
a customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such problems, espe-
cially intermittent ones. Find out what symptoms are present and
under what conditions they occur. A ªDiagnostic Worksheetº like the
example (AT-70) should be used.
Start your diagnosis by looking for ªconventionalº problems first.
This will help troubleshoot driveability problems on an electronically
controlled engine vehicle.
Also check related Service bulletins for information.
TROUBLE DIAGNOSIS Ð
INTRODUCTION
EXCEPT FOR EURO-OBD
AT-69

DIAGNOSTIC WORKSHEET=NJAT0023S01Information from CustomerNJAT0023S0101KEY POINTS
WHAT..... Vehicle & A/T model
WHEN..... Date, Frequencies
WHERE..... Road conditions
HOW..... Operating conditions, Symptoms
Customer name MR/MS Model & Year VIN
Trans. model Engine Mileage
Incident Date Manuf. Date In Service Date
FrequencyNContinuousNIntermittent ( times a day)
SymptomsNVehicle does not move. (NAny positionNParticular position)
NNo up-shift (N1st®2ndN2nd®3rdN3rd®O/D)
NNo down-shift (NO/D®3rdN3rd®2ndN2nd®1st)
NLockup malfunction
NShift point too high or too low.
NShift shock or slip (NN®DNLockupNAny drive position)
NNoise or vibration
NNo kickdown
NNo pattern select
NOthers
()
O/D OFF indicator lamp Blinks for about 8 seconds.
NContinuously litNNot lit
Malfunction indicator (MI)NContinuously litNNot lit
TROUBLE DIAGNOSIS Ð
INTRODUCTION
EXCEPT FOR EURO-OBD
Introduction (Cont'd)
AT-70

4. 4-3. Cruise testAT-92
AT-95
Part-1
N8. Vehicle Cannot Be Started From D
1, AT-311.
N9. A/T Does Not Shift: D
1®D2Or Does Not Kickdown: D4®D2, AT-314.
N10. A/T Does Not Shift: D
2®D3, AT-317.
N11. A/T Does Not Shift: D
3®D4, AT-320.
N12. A/T Does Not Perform Lock-up, AT-323.
N13. A/T Does Not Hold Lock-up Condition, AT-325.
N14. Lock-up Is Not Released, AT-327.
N15. Engine Speed Does Not Return To Idle (Light Braking D
4®D3), AT-328.
Part-2AT-99
N16. Vehicle Does Not Start From D
1, AT-330.
N9. A/T Does Not Shift: D
1®D2Or Does Not Kickdown: D4®D2, AT-314.
N10. A/T Does Not Shift: D
2®D3, AT-317.
N11. A/T Does Not Shift: D
3®D4, AT-320.
Part-3AT-101
N17. A/T Does Not Shift: D
4®D3When Overdrive Control Switch ªONº®ªOFFº, AT-331
N15. Engine Speed Does Not Return To Idle (Engine Brake In D
3), AT-328.
N18. A/T Does Not Shift: D
3®22, When Selector Lever ªDº®ª2º Position, AT-332.
N15. Engine Speed Does Not Return To Idle (Engine Brake In 2
2), AT-328.
N19. A/T Does Not Shift: 2
2®11, When Selector Lever ª2º®ª1º Position, AT-333.
N20. Vehicle Does Not Decelerate By Engine Brake, AT-334.
N21. TCM Self-diagnosis Does Not Activate (PNP, Overdrive Control and Throttle Position Switches
Circuit Checks), AT-334.
NSELF-DIAGNOSTIC PROCEDURE Ð Mark detected items.
NVehicle speed sensor´A/T (Revolution sensor), AT-126.
NVehicle speed sensor´MTR, AT-131.
NThrottle position sensor, AT-134.
NShift solenoid valve A, AT-142.
NShift solenoid valve B, AT-148.
NOverrun clutch solenoid valve, AT-154.
NTorque converter clutch solenoid valve, AT-159.
NA/T fluid temperature sensor and TCM power source, AT-165.
NEngine speed signal, AT-172.
NLine pressure solenoid valve, AT-176.
NControl unit (RAM), control unit (ROM), AT-286.
NControl unit (EEP ROM), AT-288.
NPNP, overdrive control and throttle position switches, AT-334.
NBattery
NOthers
5.NFor self-diagnosis NG items, inspect each component. Repair or replace the damaged parts. AT-40
6.NPerform all ROAD TEST and re-mark required procedures. AT-85
7.NPerform 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
symptoms and the component inspection orders.)AT-118
AT-105
8.NErase self-diagnosis code from TCM memories. AT-43
AT-49
TROUBLE DIAGNOSIS Ð
INTRODUCTION
EXCEPT FOR EURO-OBD
Introduction (Cont'd)
AT-72

SAT631IA
SAT632I
SEF234G
IntroductionNJAT0257The TCM receives a signal from the vehicle speed sensor, throttle
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 EURO-OBD related
parts of the A/T system for malfunction-diagnostic purposes. The
TCM is capable of diagnosing malfunctioning parts while the ECM
can store malfunctions 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
operating condition and be free of valve seizure, solenoid valve
malfunction, etc.
It is much more difficult to diagnose a problem that occurs intermit-
tently rather than continuously. Most intermittent problems 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.
A visual check only, may not find the cause of the problems. A road
test with CONSULT-II (or GST) or a circuit tester connected should
be performed. Follow the ªWork Flowº. Refer to AT-78.
Before undertaking actual checks, take a few minutes to talk with
a customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such problems, espe-
cially intermittent ones. Find out what symptoms are present and
under what conditions they occur. A ªDiagnostic Worksheetº like the
example (AT-75) should be used.
Start your diagnosis by looking for ªconventionalº problems first.
This will help troubleshoot driveability problems on an electronically
controlled engine vehicle.
Also check related Service bulletins for information.
TROUBLE DIAGNOSIS Ð INTRODUCTIONEURO-OBD
AT-74