
AUTOMATIC TRANSMISSION
SECTION
AT
CONTENTS
PREPARATION AND PRECAUTIONS............... 1003
Special Service Tools ...................................... 1003
Supplemental Restraint System (SRS) ªAIR
BAGº and ªSEAT BELT PRE-TENSIONERº ... 1004
Precautions ...................................................... 1004
Service Notice or Precautions ......................... 1006
OVERALL SYSTEM............................................ 1007
A/T Electrical Parts Location ........................... 1007
Circuit Diagram ................................................ 1008
Wiring Diagram Ð A/T Ð ................................ 1009
Cross-sectional View ....................................... 1022
Hydraulic Control Circuits ................................ 1023
Shift Mechanism .............................................. 1024
Control System ................................................ 1026
ON BOARD DIAGNOSTIC SYSTEM
DESCRIPTION..................................................... 1028
Self-diagnosis................................................... 1028
Diagnosis by CONSULT-II ............................... 1034
TROUBLE DIAGNOSIS Ð Introduction............ 1036
Introduction ...................................................... 1036
Diagnostic Worksheet ...................................... 1037
Work Flow ........................................................ 1040
TROUBLE DIAGNOSIS Ð Basic Inspection.... 1041
A/T Fluid Check ............................................... 1041
Stall Test .......................................................... 1041
Line Pressure Test........................................... 1044
Road Test ........................................................ 1046
TROUBLE DIAGNOSIS Ð General
Description.......................................................... 1057
Symptom Chart ................................................ 1057
TCM Terminals and Reference Value ............. 1060
TROUBLE DIAGNOSIS FOR VHCL SPEED
SENzA/T................................................................ 1064Vehicle Speed SensorzA/T (Revolution
sensor) ............................................................. 1064
TROUBLE DIAGNOSIS FOR VHCL SPEED
SENzMTR.............................................................. 1066
Vehicle Speed SensorzzMTR ............................ 1066
TROUBLE DIAGNOSIS FOR THROTTLE POSI
SEN...................................................................... 1068
Accelerator Position Sensor ............................ 1068
TROUBLE DIAGNOSIS FOR SHIFT
SOLENOID/V A.................................................... 1070
Shift Solenoid Valve A ..................................... 1070
TROUBLE DIAGNOSIS FOR SHIFT
SOLENOID/V B.................................................... 1072
Shift Solenoid Valve B ..................................... 1072
TROUBLE DIAGNOSIS FOR OVERRUN
CLUTCH S/V........................................................ 1074
Overrun Clutch Solenoid Valve ....................... 1074
TROUBLE DIAGNOSIS FOR T/C CLUTCH
SOL/V................................................................... 1076
Torque Converter Clutch Solenoid Valve ........ 1076
TROUBLE DIAGNOSIS FOR BATT/FLUID
TEMP SEN........................................................... 1079
A/T Fluid Temperature Sensor and TCM
Power Source .................................................. 1079
TROUBLE DIAGNOSIS FOR ENGINE SPEED
SIG....................................................................... 1082
Engine Speed Signal ....................................... 1082
TROUBLE DIAGNOSIS FOR LINE PRESSURE
S/V........................................................................ 1084
Line Pressure Solenoid Valve ......................... 1084
TROUBLE DIAGNOSIS FOR CONTROL UNIT
(RAM), CONTROL UNIT (ROM)......................... 1087
Description ....................................................... 1087
AT

Control System
OUTLINE
The automatic transmission senses vehicle operating conditions through various sensors. It always controls
the optimum shaft position and reduces shifting and lock-up shocks.
SENSORSTCMACTUATORS
PNP switch
Accelerator position sensor
Accelerator position switch
(Full accel, off accel position
switch)
Engine speed signal
A/T fluid temperature sensor
Revolution sensor
Vehicle speed sensor
Overdrive control switch
A/T mode switch
c
Shift control
Line pressure control
Lock-up control
Overrun clutch control
Timing control
Fail-safe control
Self-diagnosis
Duet-EU control
CONSULT-II communication line
control
c
Shift solenoid valve A
Shift solenoid valve B
Overrun clutch solenoid valve
Torque converter clutch
solenoid valve
Line pressure solenoid valve
SPORT indicator lamp
CONTROL SYSTEM
SAT207K
OVERALL SYSTEM
AT-1026

TCM FUNCTION
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.
INPUT/OUTPUT SIGNAL OF TCM
Sensors and solenoid valves Function
InputPNP switch Detects select lever position and sends a signal to TCM.
Accelerator position sensor Detects throttle valve position and sends a signal to TCM.
Accelerator position switch
(Off accel)Detects throttle valve's fully-closed position and sends a signal to TCM.
Accelerator position switch
(Full accel)Detects 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 sen-
sor (installed on transmission) malfunctions.
Overdrive control switch
A/T mode switchSends a signal, which prohibits a shift to ªD
4º (overdrive) position, to the TCM.
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 relation 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 sig-
nal sent from TCM.
O/D OFF indicator lamp
SPORT indicator lampShows TCM faults, when A/T control components malfunction.
OVERALL SYSTEM
Control System (Cont'd)
AT-1027

Self-diagnosis
After performing this procedure, place check marks for results on
the ªDIAGNOSTIC WORKSHEETº, AT-1038. Reference pages
are provided following the items.
SELF-DIAGNOSTIC PROCEDURE (With
CONSULT-II)
1. Turn on CONSULT-II and touch ªA/Tº.
If A/T is not displayed, check TCM power supply and ground
circuit. Refer to AT-1060. If result is NG, refer to EL section
(ªPOWER SUPPLY ROUTINGº).
2. Touch ªSELF-DIAG RESULTSº.
Display shows malfunction experienced since the last eras-
ing operation.
CONSULT-II performs REAL-TIME SELF-DIAGNOSIS.
Also, any malfunction detected while in this mode will be
displayed at real time.
Item Display Description Remarks
No failure
****NO FAILURE
****+No failure has been detected.
Initial start
*INITIAL START
*+This is NOT a malfunction message.
Whenever shutting off a power supply to the
TCM, this message appears on the screen.
[]
Vehicle speed sensorzA/T
(Revolution sensor)VHCL SPEED SENzA/T+No signal input from vehicle speed sensorzA/T
(revolution sensor) during traveling due to
disconnection, or input of abnormal signal.
Vehicle speed sensorzMTR
(Meter)VHCL SPEED SENzMTR+No signal input from vehicle speed sensorzMTR
during traveling due to disconnection, or input of
abnormal signal.
Accelerator position sensor THROTTLE POSI SEN+Accelerator position sensor signal voltage is abnor-
mally high.
+Throttle (accelerator) position sensor signal voltage
is abnormally low with closed throttle position
switch ªOFFº or wide open throttle position switch
ªONº.
Shift solenoid valve A SHIFT SOLENOID/V A+Specified voltage is not applied to solenoid valve
due to disconnection or shortcircuit.
Shift solenoid valve B SHIFT SOLENOID/V B+Specified voltage is not applied to solenoid valve
due to disconnection or shortcircuit.
Overrun clutch solenoid
valveOVERRUN CLUTCH S/V+Specified voltage is not applied to solenoid valve
due to disconnection or shortcircuit.
T/C clutch solenoid valve T/C CLUTCH SOL/V+Specified voltage is not applied to solenoid valve
due to disconnection or shortcircuit.
A/T fluid temperature
sensor/TCM power sourceBATT/FLUID TEMP SEN+Supply voltage to TCM is abnormally low during
traveling.
+Fluid temperature signal voltage is abnormally high
(fluid temperature is low) during traveling.To be dis-
played in case
of abnormality
and no record-
ing is made
Engine speed signal ENGINE SPEED SIG+Engine RPM is abnormally low during traveling.
Line pressure solenoid
valveLINE PRESSURE S/V+Specified voltage is not applied to solenoid valve
due to disconnection or shortcircuit.
TCM (ROM) CONTROL UNIT (ROM)+TCM memory (ROM) is malfunctioning.
TCM (RAM) CONTROL UNIT (RAM)+TCM memory (RAM) is malfunctioning.
TCM (EEP ROM) CONTROL UNIT (EEP ROM)+TCM memory (EEP ROM) is malfunctioning.
SAT014K
SAT987J
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
AT-1028

JUDGEMENT OF SELF-DIAGNOSIS CODE
SPORT indicator lamps:*1
All judgement flickers are same.
SAT819H
All circuits that can be confirmed by self-diagnosis are OK.
4th judgement flicker is longer than others.
SAT797HShift solenoid valve A circuit is short-circuited or discon-
nected.
Go to SHIFT SOLENOID VALVE A, AT-1070.
1st judgement flicker is longer than others.
SAT794H
Revolution sensor circuit is short-circuited or disconnected.
Go to VEHICLE SPEED SENSORzA/T (REVOLUTION
SENSOR), AT-1064.
5th judgement flicker is longer than others.
SAT798H
Shift solenoid valve B circuit is short-circuited or discon-
nected.
Go to SHIFT SOLENOID VALVE B, AT-1072.
2nd judgement flicker is longer than others.
SAT795H
Vehicle speed sensor circuit is short-circuited or discon-
nected.
Go to VEHICLE SPEED SENSORzMTR, AT-1066.
6th judgement flicker is longer than others.
SAT799H
Overrun clutch solenoid valve circuit is short-circuited or dis-
connected.
Go to OVERRUN CLUTCH SOLENOID VALVE, AT-1074.
3rd judgement flicker is longer than others.
SAT796H
Throttle (accelerator) position sensor circuit is short-circuited
or disconnected.
Go to ACCELERATOR POSITION SENSOR, AT-1068.
7th judgement flicker is longer than others.
SAT800H
Torque converter clutch solenoid valve circuit is short-cir-
cuited or disconnected.
Go to TORQUE CONVERTER CLUTCH SOLENOID
VALVE, AT-1076.
t1= 2.5 seconds t2= 2.0 seconds t3= 1.0 second
*1: Refer to applicable indicator lamps for specified areas on next page.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Self-diagnosis (Cont'd)
AT-1031

SPORT indicator lamps:
8th judgement flicker is longer than others.
SAT801H
A/T fluid temperature sensor is disconnected or TCM power
source circuit is damaged.
Go to A/T FLUID TEMPERATURE SENSOR AND TCM
POWER SOURCE, AT-1079.
Flickers as shown below.
SAT804H
Battery power is low.
Battery has been disconnected for a long time.
Battery is connected conversely.
(When reconnecting TCM connectors. Ð This is not a prob-
lem.)
9th judgement flicker is longer than others.
SAT802H
Engine speed signal circuit is short-circuited or disconnected.
Go to ENGINE SPEED SIGNAL, AT-1082.
Does not come on.
SAT805H
PNP, overdrive control, A/T mode or accelerator position
switches circuit is disconnected or TCM is damaged.
Go to PNP, OVERDRIVE CONTROL, A/T MODE AND
ACCELERATOR POSITION SWITCHES, AT-1091.
10th judgement flicker is longer than others.
SAT803H
Line pressure solenoid valve circuit is short-circuited or dis-
connected.
Go to LINE PRESSURE SOLENOID VALVE, AT-1084.
t4= 1.0 second
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Self-diagnosis (Cont'd)
AT-1032

Diagnosis by CONSULT-II
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, mechanical parts (except solenoids, sensors, etc.) may be malfunctioning. Check mechanical
parts using applicable diagnostic procedures.
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. Gear position dis-
played 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 dis-
played upon completion of shifting (which is computed by TCM).
4. Additional CONSULT-II information can be found in the Operation Manual supplied with the CONSULT-II
unit.
SELF-DIAGNOSTIC RESULT TEST MODE
Refer to AT-1028.
DATA MONITOR DIAGNOSTIC TEST MODE
Item DisplayMonitor item
Description Remarks TCM
input
signalsMain
signals
Vehicle speed sensor 1 (A/T)
(Revolution sensor)VHCL/S SEzA/T
[km/h] or [mph]
XÐ+Vehicle speed computed from
signal of revolution sensor is
displayed.When racing engine in ªNº or ªPº
position with vehicle stationary,
CONSULT data may not indicate
0 km/h (0 MPH).
Vehicle speed sensor 2
(Meter)VHCL/S SEzMTR
[km/h] or [mph]
XÐ+Vehicle speed computed 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.
Accelerator position sensor THRTL POS SEN
[V]XÐ+Accelerator position sensor sig-
nal voltage is displayed.
A/T fluid temperature sensor FLUID 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 dis-
played.
Engine speed ENGINE SPEED
[rpm]
XX+Engine speed, computed 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 running.
Overdrive control switch OVERDRIVE SW
[ON/OFF] X Ð+ON/OFF state computed from
signal of overdrive control SW
is displayed.
P/N position switch PN POSI SW
[ON/OFF] X Ð+ON/OFF state computed from
signal of PN position SW is dis-
played.
R position switch R POSITION SW
[ON/OFF] X Ð+ON/OFF state computed from
signal of R position SW is dis-
played.
D position switch D POSITION SW
[ON/OFF] X Ð+ON/OFF state computed from
signal of D position SW is dis-
played.
2 position switch 2 POSITION SW
[ON/OFF] X Ð+ON/OFF status, computed from
signal of 2 position SW, is dis-
played.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
AT-1034
![NISSAN PATROL 2000 Electronic Repair Manual Item DisplayMonitor item
Description Remarks TCM
input
signalsMain
signals
1 position switch 1 POSITION SW
[ON/OFF] X Ð+ON/OFF status, computed from
signal of 1 position SW, is dis-
played.
ASCD-crui NISSAN PATROL 2000 Electronic Repair Manual Item DisplayMonitor item
Description Remarks TCM
input
signalsMain
signals
1 position switch 1 POSITION SW
[ON/OFF] X Ð+ON/OFF status, computed from
signal of 1 position SW, is dis-
played.
ASCD-crui](/manual-img/5/57367/w960_57367-36.png)
Item DisplayMonitor item
Description Remarks TCM
input
signalsMain
signals
1 position switch 1 POSITION SW
[ON/OFF] X Ð+ON/OFF status, computed 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.
ASCD-OD cut signal ASCD-OD CUT
[ON/OFF]
XÐ+Status of ASCDzOD release
signal is displayed.
ON ... OD released
OFF ... OD not released+This is displayed even when no
ASCD is mounted.
Kickdown switch KICKDOWN SW
[ON/OFF] X Ð+ON/OFF status, computed from
signal of kickdown SW, is dis-
played.+This is displayed even when no
kickdown switch is equipped.
A/T mode switch POWER SHIFT SW
[ON/OFF] X Ð+ON/OFF state computed from
signal of POWER shift SW is
displayed.
Closed throttle position switch CLOSED THL/SW
[ON/OFF]
XÐ+ON/OFF status, computed from
signal of closed throttle (accel-
erator) position SW, is dis-
played.
Wide open throttle position switch W/O THRL/P-SW
[ON/OFF]
XÐ+ON/OFF status, computed from
signal of wide open throttle
(accelerator) position SW, is
displayed.
A/T mode switch HOLD SW
[ON/OFF] X Ð+ON/OFF status, computed from
signal of HOLD shift SW, is
displayed.
Gear position GEAR
ÐX+Gear position data used for
computation by TCM, is dis-
played.
Selector lever position SLCT LVR POSI
ÐX+Selector lever position data,
used for computation by TCM,
is displayed.+A specific value used for con-
trol is displayed if fail-safe is
activated due to error.
Vehicle speed VEHICLE SPEED
[km/h] or [mph] Ð X+Vehicle speed data, used for
computation by TCM, is dis-
played.
Accelerator position THROTTLE POSI
[/8] Ð X+Throttle (accelerator) position
data, used for computation by
TCM, is displayed.+A specific value used for con-
trol is displayed if fail-safe is
activated due to error.
Line pressure duty LINE PRES DTY
[%]
ÐX+Control value of line pressure
solenoid valve, computed by
TCM from each input signal, is
displayed.
Torque converter clutch solenoid
valve dutyTCC S/V DUTY
[%]
ÐX+Control value of torque con-
verter clutch solenoid valve,
computed by TCM from each
input signal, is displayed.
Shift solenoid valve A SHIFT S/V A
[ON/OFF]
ÐX+Control value of shift solenoid
valve A, computed by TCM
from each input signal, is dis-
played.Control value of solenoid is dis-
played even if solenoid circuit is
disconnected.
The ªOFFº signal is displayed if
solenoid circuit is shorted.
Shift solenoid valve B SHIFT S/V B
[ON/OFF]
ÐX+Control value of shift solenoid
valve B, computed by TCM
from each input signal, is dis-
played.
Overrun clutch solenoid valve OVERRUN/C S/V
[ON/OFF]
ÐX+Control value of overrun clutch
solenoid valve computed by
TCM from each input signal is
displayed.
Self-diagnosis display lamp
(SPORT indicator lamp)SELF-D DP LMP
[ON/OFF]ÐX+Control status of SPORT indi-
cator lamp is displayed.
X: Applicable
Ð: Not applicable
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Diagnosis by CONSULT-II (Cont'd)
AT-1035