2001 NISSAN ALMERA o2 sensor

Control System=NJAT0014OUTLINENJAT0014S01The automatic transaxle senses vehicle operating conditions through various switches and sensors. It always
controls the optimum shift position and reduces shifting and lock-up shocks.
SWITCHES & SENSORS
cTCM
cACTUATORS
PNP switch
Throttle position sensor
Closed throttle position switch
Wide open throttle position
switch
Engine speed signal
A/T fluid temperature sensor
Revolution sensor
Vehicle speed sensor
Overdrive control switch
Stop lamp switchShift control
Line pressure control
Lock-up control
Overrun clutch control
Timing control
Fail-safe control
Self-diagnosis
CONSULT-II communication line
control
Duet-EA controlShift solenoid valve A
Shift solenoid valve B
Overrun clutch solenoid valve
Torque converter clutch solenoid
valve
Line pressure solenoid valve
O/D OFF indicator lamp
CONTROL SYSTEMNJAT0014S02
SAT995J
OVERALL SYSTEM
Control System
AT-31

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

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
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OVERALL SYSTEM
Control Mechanism (Cont'd)
AT-34

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

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.
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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

SELF-DIAGNOSTIC RESULT TEST MODENJAT0022S03
Detected items
(Screen terms for CONSULT-II, ªSELF-DIAG
RESULTSº test mode)Malfunction is detected when ... Remarks
Item Display
No failure
(NO SELF DIAGNOSTIC FAILURE INDICATED
FURTHER TESTING MAY BE REQUIRED**)+No failure has been detected.
Initial start+This is not a malfunction message (Whenever shut-
ting off a power supply to the TCM, this message
appears on the screen.) INITIAL START
Ð
Revolution sensor VHCL SPEED
SEN´A/T+TCM does not receive the proper voltage signal from
the sensor.
Vehicle speed sensor
(Meter)VHCL SPEED
SEN´MTR+TCM does not receive the proper voltage signal from
the sensor.
Throttle position sen-
sor
Throttle position switchTHROTTLE POSI
SEN+TCM receives an excessively low or high voltage
from the sensor.
Shift solenoid valve A SHIFT SOLENOID/V A+TCM detects an improper voltage drop when it tries
to operate the solenoid valve.
Shift solenoid valve B SHIFT SOLENOID/V B+TCM detects an improper voltage drop when it tries
to operate the solenoid valve.
Overrun clutch sole-
noid valveOVERRUN CLUTCH
S/V+TCM detects an improper voltage drop when it tries
to operate the solenoid valve.
T/C clutch solenoid
valveT/C CLUTCH SOL/V+TCM detects an improper voltage drop when it tries
to operate the solenoid valve.
A/T fluid temperature
sensorBATT/FLUID TEMP
SEN+TCM receives an excessively low or high voltage
from the sensor.To be displayed in
case of abnormality
and when no recording
is made.
Engine speed signal ENGINE SPEED SIG+TCM does not receive the proper voltage signal from
the ECM.
Line pressure solenoid
valveLINE PRESSURE S/V+TCM detects an improper voltage drop when it tries
to operate the solenoid valve.
TCM (RAM) CONTROL UNIT
(RAM)+TCM memory (RAM) is malfunctioning.
TCM (ROM) CONTROL UNIT
(ROM)+TCM memory (ROM) is malfunctioning.
TCM (EEP ROM) CONT UNIT (EEP
ROM)+TCM memory (EEP ROM) is malfunctioning.
DATA MONITOR MODE (A/T)NJAT0022S04
Item DisplayMonitor item
Description Remarks
ECU input
signalsMain sig-
nals
Vehicle speed sensor 1
(A/T)
(Revolution sensor)VHCL/S SE´A/T
[km/h] or [mph]
XÐ+Vehicle speed com-
puted from signal of
revolution sensor is dis-
played.When racing engine in ªNº
or ªPº position with vehicle
stationary, CONSULT-II
data may not indicate 0
km/h (0 mph).
ON BOARD DIAGNOSTIC
SYSTEM DESCRIPTION
EXCEPT FOR EURO-OBD
CONSULT-II (Cont'd)
AT-40

Item DisplayMonitor item
Description Remarks
ECU input
signalsMain sig-
nals
Vehicle speed sensor 2
(Meter)VHCL/S SE´MTR
[km/h] or [mph]
XÐ+Vehicle speed com-
puted from signal of
vehicle speed sensor is
displayed.Vehicle speed display may
not be accurate under
approx. 10 km/h (6 mph).
It may not indicate 0 km/h
(0 mph) when vehicle is
stationary.
Throttle position sensor THRTL POS SEN
[V] X Ð+Throttle position sensor
signal voltage is dis-
played.
A/T fluid temperature sen-
sorFLUID TEMP SE
[V]
XÐ+A/T fluid temperature
sensor signal voltage is
displayed.
+Signal voltage lowers as
fluid temperature rises.
Battery voltage BATTERY VOLT
[V]XÐ+Source voltage of TCM
is displayed.
Engine speed ENGINE SPEED
[rpm]
XX+Engine speed, com-
puted from engine
speed signal, is dis-
played.Engine speed display may
not be accurate under
approx. 800 rpm. It may
not indicate 0 rpm even
when engine is not run-
ning.
Overdrive control switch OVERDRIVE SW
[ON/OFF]
XÐ+ON/OFF state com-
puted from signal of
overdrive control SW is
displayed.
P/N position switch PN POSI SW
[ON/OFF]
XÐ+ON/OFF state com-
puted from signal of P/N
position SW is dis-
played.
R position switch R POSITION SW
[ON/OFF]
XÐ+ON/OFF state com-
puted from signal of R
position SW is dis-
played.
D position switch D POSITION SW
[ON/OFF]
XÐ+ON/OFF state com-
puted from signal of D
position SW is dis-
played.
2 position switch 2 POSITION SW
[ON/OFF]
XÐ+ON/OFF status, com-
puted from signal of 2
position SW, is dis-
played.
1 position switch 1 POSITION SW
[ON/OFF]
XÐ+ON/OFF status, com-
puted from signal of 1
position SW, is dis-
played.
ASCD cruise signal ASCD-CRUISE
[ON/OFF]
XÐ+Status of ASCD cruise
signal is displayed.
ON ... Cruising state
OFF ... Normal running
state+This is displayed even
when no ASCD is
mounted.
ON BOARD DIAGNOSTIC
SYSTEM DESCRIPTION
EXCEPT FOR EURO-OBD
CONSULT-II (Cont'd)
AT-41

6 CHECK SELF-DIAGNOSIS CODE
Check O/D OFF indicator lamp. Refer to JUDGEMENT OF SELF-DIAGNOSIS CODE, AT-47.
SAT123KA
©DIAGNOSIS END
JUDGEMENT OF SELF-DIAGNOSIS CODENJAT0230S02
O/D OFF indicator lamp:
All judgement flickers are the same.
SAT436F
All circuits that can be confirmed by self-diagnosis are OK.1st judgement flicker is longer than others.
SAT437F
Revolution sensor circuit is short-circuited or disconnected.
ÞGo to VEHICLE SPEED SENSOR´A/T (REVOLUTION SEN-
SOR).
General: AT-126
2nd judgement flicker is longer than others.
SAT439F
Vehicle speed sensor circuit is short-circuited or disconnected.
ÞGo to VEHICLE SPEED SENSOR´MTR.
General: AT-1313rd judgement flicker is longer than others.SAT441F
Throttle position sensor circuit is short-circuited or disconnected.
ÞGo to THROTTLE POSITION SENSOR.
General: AT-134
ON BOARD DIAGNOSTIC
SYSTEM DESCRIPTION
EXCEPT FOR EURO-OBD
Diagnostic Procedure Without CONSULT-II (Cont'd)
AT-47