2001 NISSAN ALMERA ESP

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.
+Transaxle failure did not display evidence of damaged or worn internal parts, steel particles or clutch plate
lining 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.
EURO-OBD SELF-DIAGNOSIS Ð EURO-OBD ÐNJAT0247S04+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 O/D OFF indicator or the malfunction indicator (MI). Refer to the table on AT-55
for the indicator used to display each self-diagnostic result.
+The self-diagnostic results indicated by the MI are automatically stored in both the ECM and TCM memo-
ries.
Always perform the procedure ªHOW TO ERASE DTCº on AT-52 to complete the repair and avoid
unnecessary blinking of the MI.
+The following self-diagnostic items can be detected using ECM self-diagnostic results mode* only when
the O/D OFF indicator lamp does not indicate any malfunctions.
þ PNP switch
þ A/T 1st, 2nd, 3rd, or 4th gear function
*: For details of EURO-OBD, refer to EC-59, ªON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONº.
+Certain systems and components, especially those related to EURO-OBD, may use a new style
slide-locking type harness connector.
For description and how to disconnect, refer to EL-6, ªHARNESS CONNECTORº.
Wiring Diagrams and Trouble DiagnosisNJAT0248When you read wiring diagrams, refer to the following:
+GI-11, ªHOW TO READ WIRING DIAGRAMSº
+EL-10, ªPOWER SUPPLY ROUTINGº
When you perform trouble diagnosis, refer to the following:
+GI-32, ªHOW TO FOLLOW TEST GROUP IN TROUBLE DIAGNOSISº
+GI-21, ªHOW TO PERFORM EFFICIENT DIAGNOSIS FOR AN ELECTRICAL INCIDENTº
PRECAUTIONS
Service Notice or Precautions (Cont'd)
AT-10

TCM FUNCTION=NJAT0014S03The 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.
INPUT/OUTPUT SIGNAL OF TCMNJAT0014S04
Sensors, switches and solenoid
valvesFunction
InputPNP switch Detects select lever position and sends a signal to TCM.
Throttle position sensor Detects throttle valve position and sends a signal to TCM.
Closed throttle position switch Detects throttle valve's fully-closed position and sends a signal to TCM.
Wide open throttle position switchDetects a throttle valve position of greater than 1/2 of full throttle and sends
a signal to TCM.
Engine speed signal From ECM.
A/T fluid temperature sensor Detects transmission fluid temperature and sends a signal to TCM.
Revolution sensor Detects output shaft rpm and sends a signal to TCM.
Vehicle speed sensorUsed as an auxiliary vehicle speed sensor. Sends a signal when revolution
sensor (installed on transmission) malfunctions.
Overdrive control switchSends a signal, which prohibits a shift to ªD
4º (overdrive) position, to the
TCM.
Stop lamp switch Releases lock-up system when depressing pedal in lock-up condition.
OutputShift solenoid valve A/BSelects shifting point suited to driving conditions in relation to a signal sent
from TCM.
Line pressure solenoid valveRegulates (or decreases) line pressure suited to driving conditions in rela-
tion to a signal sent from TCM.
Torque converter clutch solenoid
valveRegulates (or decreases) lock-up pressure suited to driving conditions in
relation to a signal sent from TCM.
Overrun clutch solenoid valveControls an ªengine brakeº effect suited to driving conditions in relation to a
signal sent from TCM.
O/D OFF indicator lamp Shows TCM faults, when A/T control components malfunction.
Control MechanismNJAT0015LINE PRESSURE CONTROLNJAT0015S01TCM has various line pressure control characteristics to match the
driving conditions.
An ON-OFF duty signal is sent to the line pressure solenoid valve
based on TCM characteristics.
Hydraulic pressure on the clutch and brake is electronically con-
trolled through the line pressure solenoid valve to accommodate
engine torque. This results in smooth shift operation.
OVERALL SYSTEM
Control System (Cont'd)
AT-32

SAT003J
Normal ControlNJAT0015S0101The line pressure to throttle opening characteristics is set for suit-
able clutch operation.
SAT004J
Back-up Control (Engine brake)NJAT0015S0102If the selector lever is shifted to ª2º position while driving in D4(OD)
or D
3, great driving force is applied to the clutch inside the trans-
mission. Clutch operating pressure (line pressure) must be
increased to deal with this driving force.
SAT005J
During Shift ChangeNJAT0015S0103The line pressure is temporarily reduced corresponding to a
change in engine torque when shifting gears (that is, when the shift
solenoid valve is switched for clutch operation) to reduce shifting
shock.
At Low Fluid TemperatureNJAT0015S0104+Fluid viscosity and frictional characteristics of the clutch facing
change with fluid temperature. Clutch engaging or band-con-
tacting pressure is compensated for, according to fluid
temperature, to stabilize shifting quality.
SAT006J
+The line pressure is reduced below 60ÉC (140ÉF) to prevent
shifting shock due to low viscosity of automatic transmission
fluid when temperature is low.
OVERALL SYSTEM
Control Mechanism (Cont'd)
AT-33

SAT007J
+Line pressure is increased to a maximum irrespective of the
throttle opening when fluid temperature drops to þ10ÉC (14ÉF).
This pressure rise is adopted to prevent a delay in clutch and
brake operation due to extreme drop of fluid viscosity at low
temperature.
SHIFT CONTROLNJAT0015S02The shift is regulated entirely by electronic control to accommodate
vehicle speed and varying engine operations. This is accomplished
by electrical signals transmitted by the revolution sensor and
throttle position sensor. This results in improved acceleration per-
formance and fuel economy.
SAT008J
Control of Shift Solenoid Valves A and BNJAT0015S0201The TCM activates shift solenoid valves A and B according to sig-
nals from the throttle position sensor and revolution sensor to
select the optimum gear position on the basis of the shift schedule
memorized in the TCM.
The shift solenoid valve performs simple ON-OFF operation. When
set to ªONº, the drain circuit closes and pilot pressure is applied to
the shift valve.
Relation Between Shift Solenoid Valves A and B and
Gear Positions
NJAT0015S0203
Shift solenoid valveGear position
D
1,21,11D2,22,12D3D4(OD) N-P
A ON (Closed) OFF (Open) OFF (Open) ON (Closed) ON (Closed)
B ON (Closed) ON (Closed) OFF (Open) OFF (Open) ON (Closed)
Control of Shift Valves A and BNJAT0015S0202
SAT009J
OVERALL SYSTEM
Control Mechanism (Cont'd)
AT-34

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

IntroductionNJAT0251The A/T system has two self-diagnostic systems.
The first is the emission-related on board diagnostic system (EURO-OBD) performed by the TCM in combi-
nation with the ECM. The malfunction is indicated by the MI (malfunction indicator) and is stored as a DTC in
the ECM memory but not the TCM memory.
The second is the TCM original self-diagnosis indicated by the O/D OFF indicator lamp. The malfunction is
stored in the TCM memory. The detected items are overlapped with EURO-OBD self-diagnostic items. For
detail, refer to AT-55.
EURO-OBD Function for A/T SystemNJAT0252The ECM provides emission-related on board diagnostic (EURO-OBD) functions for the A/T system. One
function is to receive a signal from the TCM used with EURO-OBD-related parts of the A/T system. The sig-
nal is sent to the ECM when a malfunction occurs in the corresponding EURO-OBD-related part. The other
function is to indicate a diagnostic result by means of the MI (malfunction indicator) on the instrument panel.
Sensors, switches and solenoid valves are used as sensing elements.
The MI automatically illuminates in One or Two Trip Detection Logic when a malfunction is sensed in relation
to A/T system parts.
One or Two Trip Detection Logic of EURO-OBDNJAT0253ONE TRIP DETECTION LOGICNJAT0253S01If a malfunction is sensed during the first test drive, the MI will illuminate and the malfunction will be stored
in the ECM memory as a DTC. The TCM is not provided with such a memory function.
TWO TRIP DETECTION LOGICNJAT0253S02When a malfunction is sensed during the first test drive, it is stored in the ECM memory as a 1st trip DTC
(diagnostic trouble code) or 1st trip freeze frame data. At this point, the MI will not illuminate. Ð First Trip
If the same malfunction as that experienced during the first test drive is sensed during the second test drive,
the MI will illuminate. Ð Second Trip
A/T-related parts for which the MI illuminates during the first or second test drive are listed below.
ItemsMI
One trip detection Two trip detection
Shift solenoid valve A Ð DTC: P0750 X
Shift solenoid valve B Ð DTC: P0755 X
Throttle position sensor or switch Ð DTC: P1705 X
Except aboveX
The ªtripº in the ªOne or Two Trip Detection Logicº means a driving mode in which self-diagnosis is performed
during vehicle operation.
EURO-OBD Diagnostic Trouble Code (DTC)NJAT0254HOW TO READ DTC AND 1ST TRIP DTCNJAT0254S01DTC and 1st trip DTC can be read by the following methods.
(
with CONSULT-II orGST)CONSULT-II or GST (Generic Scan Tool) Examples: P0705, P0710, P0720,
P0725, etc.
These DTCs are prescribed by SAE J2012.
(CONSULT-II also displays the malfunctioning component or system.)
+1st trip DTC No. is the same as DTC No.
+Output of the diagnostic trouble code indicates that the indicated circuit has a malfunction.
However, in case of the Mode II and GST they do not indicate whether the malfunction is still
occurring or occurred in the past and returned to normal.
CONSULT-II can identify them as shown below. Therefore, using CONSULT-II (if available) is rec-
ommended.
A sample of CONSULT-II display for DTC is shown in the following page. DTC or 1st trip DTC of a malfunc-
tion is displayed in SELF DIAGNOSIS mode for ªENGINEº with CONSULT-II. Time data indicates how many
times the vehicle was driven after the last detection of a DTC.
ON BOARD DIAGNOSTIC SYSTEM
DESCRIPTION
EURO-OBD
Introduction
AT-50

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

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