engine INFINITI QX4 2001 Factory Owner's Manual

Valve name Function
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 up-shifting (1st,2nd,3rd,4th gears/4th
,3rd,2nd,1st gears) in combination with shift valve B.
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.
Shuttle shift valve S Switches hydraulic circuits to provide 3-2 timing control and overrun clutch control in
relation to the throttle opening.
Inactivates the overrun clutch to prevent interlocking in 4th gear when the throttle is
wide open.
Overrun clutch control valve Switches hydraulic circuits to prevent engagement of the overrun clutch simulta-
neously with application of the brake band in 4th gear. (Interlocking occurs if the
overrun clutch engages during D
4gear operation.)
4-2 relay valve Memorizes that the transmission is in 4th gear. Prevents the transmission from down-
shifting from 4th gear to 3rd and then to 2nd in combination with 4-2 sequence valve
and shift valves A and B when downshifting from 4th to 2nd gear.
4-2 sequence valve Prevents band servo pressure from draining before high clutch operating pressure
and band servo releasing pressure drain (from the same circuit) during downshifting
from 4th to 2nd gear.
Servo charger valve An accumulator and a one-way orifice are used in the 2nd gear band servo oil circuit
to dampen shifting shock when shifting from 1st to 2nd gear.
To maintain adequate flow rate when downshifting from 4th or 3rd gear to 2nd gear,
the servo charger valve directs 2nd gear band servo hydraulic pressure to the circuit
without going through the one-way orifice when downshifting from 3rd or a higher
gear.
3-2 timing valve Prevents a late operation of the brake band when shifting selector lever from ªDº to
ª1º or ª2º position while driving in D
3.
ª1º reducing valve Reduces low & reverse brake pressure to dampen engine-brake shock when down-
shifting from the ª1º position 2nd gear to 1st gear.
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,
torque converter clutch control plug and
torque converter clutch control sleeveActivate or inactivate the lock-up function.
Also provide smooth lock-up through transient application and release of the lock-up
system.
Shuttle shift valve D Switches hydraulic circuits so that output pressure of the torque converter clutch sole-
noid valve acts on the lock-up valve in the ªDº position of 2nd, 3rd and 4th gears. (In
the ªDº position 1st gear, lock-up is inhibited.)
ILock-up control is not affected in ªDº position 2nd, 3rd or 4th gears, unless output
pressure of the torque converter clutch solenoid valve is generated by a signal
from the control unit.
OVERALL SYSTEM
Control Valve (Cont'd)
AT-32

IntroductionNBAT0014The A/T system has two self-diagnostic systems.
The first is the emission-related on board diagnostic system (OBD-II) performed by the TCM in combination
with the ECM. The malfunction is indicated by the MIL (malfunction indicator lamp) 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 OBD-II self-diagnostic items. For detail,
refer to AT-38.
OBD-II Function for A/T SystemNBAT0182The ECM provides emission-related on board diagnostic (OBD-II) functions for the A/T system. One function
is to receive a signal from the TCM used with OBD-related parts of the A/T system. The signal is sent to the
ECM when a malfunction occurs in the corresponding OBD-related part. The other function is to indicate a
diagnostic result by means of the MIL (malfunction indicator lamp) on the instrument panel. Sensors, switches
and solenoid valves are used as sensing elements.
The MIL automatically illuminates in One or Two Trip Detection Logic when a malfunction is sensed in rela-
tion to A/T system parts.
One or Two Trip Detection Logic of OBD-IINBAT0015ONE TRIP DETECTION LOGICNBAT0015S01If a malfunction is sensed during the first test drive, the MIL 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 LOGICNBAT0015S02When 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 MIL 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 MIL will illuminate. Ð Second Trip
A/T-related parts for which the MIL illuminates during the first or second test drive are listed below.
ItemsMIL
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.
OBD-II Diagnostic Trouble Code (DTC)NBAT0016HOW TO READ DTC AND 1ST TRIP DTCNBAT0016S01DTC 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.)
I1st trip DTC No. is the same as DTC No.
IOutput 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 and 1st trip DTC is shown on the next page. DTC or 1st trip DTC
of a malfunction is displayed in SELF-DIAGNOSTIC RESULTS mode for ªENGINEº with CONSULT-II. Time
data indicates how many times the vehicle was driven after the last detection of a DTC.
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Introduction
AT-33

SAT014K
If the DTC is being detected currently, the time data will be ª0º.
SAT015K
If a 1st trip DTC is stored in the ECM, the time data will be ª1tº.
SAT016K
Freeze Frame Data and 1st Trip Freeze Frame DataNBAT0016S0101The ECM has a memory function, which stores the driving condition such as fuel system status, calculated
load value, engine coolant temperature, short term fuel trim, long term fuel trim, engine speed and vehicle
speed at the moment the ECM detects a malfunction.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data,
and the data, stored together with the DTC data, are called freeze frame data and displayed on CONSULT-II
or GST. The 1st trip freeze frame data can only be displayed on the CONSULT-II screen, not on the GST. For
detail, refer to EC-81, ªCONSULT-IIº.
Only one set of freeze frame data (either 1st trip freeze frame data of freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM memory along with the 1st trip DTC. There is no prior-
ity for 1st trip freeze frame data and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MIL on) is stored in the ECM memory, 1st trip freeze frame data is no
longer stored. Remember, only one set of freeze frame data can be stored in the ECM. The ECM has the fol-
lowing priorities to update the data.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
OBD-II Diagnostic Trouble Code (DTC) (Cont'd)
AT-34

Priority Items
1 Freeze frame data Misfire Ð DTC: P0300 - P0306
Fuel Injection System Function Ð DTC: P0171, P0172, P0174, P0175
2 Except the above items (Includes A/T related items)
3 1st trip freeze frame data
Both 1st trip freeze frame data and freeze frame data (along with the DTCs) are cleared when the ECM
memory is erased.
HOW TO ERASE DTCNBAT0016S02The diagnostic trouble code can be erased by CONSULT-II, GST or ECM DIAGNOSTIC TEST MODE as
described following.
IIf the battery terminal is disconnected, the diagnostic trouble code will be lost within 24 hours.
IWhen you erase the DTC, using CONSULT-II or GST is easier and quicker than switching the mode
selector on the ECM.
The following emission-related diagnostic information is cleared from the ECM memory when erasing DTC
related to OBD-II. For details, refer to EC-60, ªEmission-related Diagnostic Informationº.
IDiagnostic trouble codes (DTC)
I1st trip diagnostic trouble codes (1st trip DTC)
IFreeze frame data
I1st trip freeze frame data
ISystem readiness test (SRT) codes
ITest values
HOW TO ERASE DTC (WITH CONSULT-II)NBAT0016S03IIf a DTC is displayed for both ECM and TCM, it needs to be erased for both ECM and TCM.
1. If the ignition switch stays ªONº after repair work, be sure to turn ignition switch ªOFFº once. Wait at least
5 seconds and then turn it ªONº (engine stopped) again.
2. Turn CONSULT-II ªONº and touch ªA/Tº.
3. Touch ªSELF-DIAG RESULTSº.
4. Touch ªERASEº. (The DTC in the TCM will be erased.) Then touch ªBACKº twice.
5. Touch ªENGINEº.
6. Touch ªSELF-DIAG RESULTSº.
7. Touch ªERASEº. (The DTC in the ECM will be erased.)
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
OBD-II Diagnostic Trouble Code (DTC) (Cont'd)
AT-35

SAT017K
HOW TO ERASE DTC (WITH GST)NBAT0016S041. If the ignition switch stays ªONº after repair work, be sure to turn ignition switch ªOFFº once. Wait at least
5 seconds and then turn it ªONº (engine stopped) again.
2. Perform ªOBD-II SELF-DIAGNOSTIC PROCEDURE (No Tools)º. Refer to AT-46. (The engine warm-up
step can be skipped when performing the diagnosis only to erase the DTC.)
3. Select Mode 4 with Generic Scan Tool (GST). For details, refer to EC-95, ªDESCRIPTIONº.
HOW TO ERASE DTC (NO TOOLS)NBAT0016S051. If the ignition switch stays ªONº after repair work, be sure to turn ignition switch ªOFFº once. Wait at least
5 seconds and then turn it ªONº (engine stopped) again.
2. Perform ªTCM SELF-DIAGNOSTIC PROCEDURE (No Tools)º. Refer to AT-46. (The engine warm-up step
can be skipped when performing the diagnosis only to erase the DTC.)
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
OBD-II Diagnostic Trouble Code (DTC) (Cont'd)
AT-36

SAT964I
Malfunction Indicator Lamp (MIL)=NBAT0183The MIL is located on the instrument panel.
1. The MIL will light up when the ignition switch is turned ON
without the engine running. This is a bulb check.
IIf the MIL does not light up, refer to EL-114, ªSchematicº.
(Or refer to EC-648, ªWiring Diagramº.)
2. When the engine is started, the MIL should go off.
If the MIL remains on, the on board diagnostic system has
detected an engine system malfunction. For detail, refer to
EC-59, ªIntroductionº.
CONSULT-IINBAT0184After performing ªSELF-DIAGNOSTIC PROCEDURE (WITH CON-
SULT-II)º (AT-37), place check marks for results on the ªDIAGNOS-
TIC WORKSHEETº, AT-55. 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:
IActual shift schedule has more or less tolerance or allowance,
IShift schedule indicated in Service Manual refers to the point
where shifts start, and
IGear 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.
SAT014K
SELF-DIAGNOSTIC PROCEDURE (WITH CONSULT-II)NBAT0184S011. Turn on CONSULT-II and touch ªENGINEº for OBD-II detected
items or touch ªA/Tº for TCM self-diagnosis.
If A/T is not displayed, check TCM power supply and ground
circuit. Refer to AT-92. If result is NG, refer to EL-9, ªSche-
maticº.
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Malfunction Indicator Lamp (MIL)
AT-37

SAT987J
2. Touch ªSELF-DIAG RESULTSº.
Display shows malfunction experienced since the last erasing
operation.
CONSULT-II performs REAL-TIME SELF-DIAGNOSIS.
Also, any malfunction detected while in this mode will be dis-
played at real time.
SELF-DIAGNOSTIC RESULT TEST MODENBAT0184S02
Detected items
(Screen terms for CONSULT-II, ªSELF-DIAG
RESULTSº test mode)
Malfunction is detected when ...TCM self-diagnosis OBD-II (DTC)
Available by
O/D OFF
indicator lamp or
ªA/Tº on CONSULT-IIAvailable by
malfunction
indicator lamp*2,
ªENGINEº on CON-
SULT-II or GST ªA/Tº ªENGINEº
PNP switch circuitITCM does not receive the cor-
rect voltage signal (based on
the gear position) from the
switch.Ð P0705
ÐPNP SW/CIRC
Revolution sensorITCM does not receive the
proper voltage signal from the
sensor.X P0720
VHCL SPEED
SEN´A/TVEH SPD SEN/CIR
AT
Vehicle speed sensor (Meter)ITCM does not receive the
proper voltage signal from the
sensor.XÐ
VHCL SPEED
SEN´MTRÐ
A/T 1st gear functionIA/T cannot be shifted to the 1st
gear position even if electrical
circuit is good.Ð P0731*1
ÐA/T 1ST GR FNCTN
A/T 2nd gear functionIA/T cannot be shifted to the 2nd
gear position even if electrical
circuit is good.Ð P0732*1
ÐA/T 2ND GR FNCTN
A/T 3rd gear functionIA/T cannot be shifted to the 3rd
gear position even if electrical
circuit is good.Ð P0733*1
ÐA/T 3RD GR FNCTN
A/T 4th gear functionIA/T cannot be shifted to the 4th
gear position even if electrical
circuit is good.Ð P0734*1
ÐA/T 4TH GR FNCTN
A/T TCC S/V function (lock-up)IA/T cannot perform lock-up
even if electrical circuit is good.Ð P0744*1
Ð A/T TCC S/V FNCTN
Shift solenoid valve AITCM detects an improper volt-
age drop when it tries to operate
the solenoid valve.X P0750
SHIFT SOLENOID/V
ASFT SOL A/CIRC
Shift solenoid valve BITCM detects an improper volt-
age drop when it tries to operate
the solenoid valve.X P0755
SHIFT SOLENOID/V
BSFT SOL B/CIRC
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT-II (Cont'd)
AT-38

Detected items
(Screen terms for CONSULT-II, ªSELF-DIAG
RESULTSº test mode)
Malfunction is detected when ...TCM self-diagnosis OBD-II (DTC)
Available by
O/D OFF
indicator lamp or
ªA/Tº on CONSULT-IIAvailable by
malfunction
indicator lamp*2,
ªENGINEº on CON-
SULT-II or GST ªA/Tº ªENGINEº
Overrun clutch solenoid valveITCM detects an improper volt-
age drop when it tries to operate
the solenoid valve.X P1760
OVERRUN CLUTCH
S/VO/R CLUCH SOL/
CIRC
T/C clutch solenoid valveITCM detects an improper volt-
age drop when it tries to operate
the solenoid valve.X P0740
T/C CLUTCH SOL/V TCC SOLENOID/
CIRC
Line pressure solenoid valveITCM detects an improper volt-
age drop when it tries to operate
the solenoid valve.X P0745
LINE PRESSURE
S/VL/PRESS SOL/CIRC
Throttle position sensor
Throttle position switchITCM receives an excessively
low or high voltage from the
sensor.X P1705
THROTTLE POSI
SENTP SEN/CIRC A/T
Engine speed signalITCM does not receive the
proper voltage signal from the
ECM.X P0725
ENGINE SPEED SIG
A/T fluid temperature sensorITCM receives an excessively
low or high voltage from the
sensor.X P0710
BATT/FLUID TEMP
SENATF TEMP SEN/
CIRC
Engine controlIThe ECM-AT communication
line is open or shorted.X EC-440, EC-603
A/T COMM LINE Ð
Turbine revolution sensorITCM does not receive the
proper voltage signal from the
sensor.XÐ
TURBINE REV
Ð
TCM (RAM)ITCM memory (RAM) is malfunc-
tioning.
ÐÐ
CONTROL UNIT
(RAM)Ð
TCM (ROM)ITCM memory (ROM) is malfunc-
tioning.
ÐÐ
CONTROL UNIT
(ROM)Ð
TCM (EEP ROM)ITCM memory (EEP ROM) is
malfunctioning.
ÐÐ
CONTROL UNIT
(EEP ROM)Ð
Initial startIThis is not a malfunction mes-
sage (Whenever shutting off a
power supply to the TCM, this
message appears on the
screen.)XÐ
INITIAL START
Ð
No failure
(NO DTC IS DETECTED FURTHER TEST-
ING MAY BE REQUIRED)INo failure has been detected.
XX
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT-II (Cont'd)
AT-39

X: Applicable
Ð: Not applicable
*1: These malfunctions cannot be displayed by MIL
if another malfunction is assigned to MIL.
*2: Refer to EC-74, ªDESCRIPTIONº.
DATA MONITOR MODE (A/T)NBAT0184S03
Item DisplayMonitor item
Description Remarks
TCM input
signalsMain sig-
nals
Vehicle speed sensor 1
(A/T)
(Revolution sensor)VHCL/S SE´A/T
[km/h] or [mph]
XÐIVehicle speed computed
from signal of revolution
sensor is displayed.When racing engine in ªNº
or ªPº position with vehicle
stationary, CONSULT-II
data may not indicate 0
km/h (0 mph).
Vehicle speed sensor 2
(Meter)VHCL/S SE´MTR
[km/h] or [mph]
XÐIVehicle speed computed
from signal of vehicle
speed sensor is dis-
played.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 sta-
tionary.
Throttle position sensor THRTL POS
SEN
[V]XÐIThrottle position sensor
signal voltage is dis-
played.
A/T fluid temperature sen-
sorFLUID TEMP SE
[V]
XÐIA/T fluid temperature
sensor signal voltage is
displayed.
ISignal voltage lowers as
fluid temperature rises.
Battery voltage BATTERY VOLT
[V]XÐISource voltage of TCM
is displayed.
Engine speed ENGINE SPEED
[rpm]
XXIEngine speed, computed
from engine speed
signal, is displayed.Engine speed display may
not be accurate under
approx. 800 rpm. It may
not indicate 0 rpm even
when engine is not run-
ning.
Turbine revolution sensor TURBINE REV
[rpm]
XÐITurbine revolution com-
puted from signal of tur-
bine revolution sensor is
displayed.Error may occur under
approx. 800 rpm and will
not indicate 0 rpm even if
engine is not running.
Overdrive control switch OVERDRIVE SW
[ON/OFF] X ÐION/OFF state computed
from signal of overdrive
control SW is displayed.
PN position switch PN POSI SW
[ON/OFF] X ÐION/OFF state computed
from signal of PN posi-
tion SW is displayed.
R position switch R POSITION SW
[ON/OFF] X ÐION/OFF state computed
from signal of R position
SW is displayed.
D position switch D POSITION SW
[ON/OFF] X ÐION/OFF state computed
from signal of D position
SW is displayed.
2 position switch 2 POSITION SW
[ON/OFF]
XÐION/OFF status, com-
puted from signal of 2
position SW, is dis-
played.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT-II (Cont'd)
AT-40

1 CHECK O/D OFF INDICATOR LAMP
1. Start the engine with selector lever in ªPº position. Warm engine to normal operating temperature.
2. Turn ignition switch to ªOFFº position.
3. Wait 5 seconds.
SAT967I
4. Turn ignition switch to ªONº position.
(Do not start engine.)
5. Does O/D OFF indicator lamp come on for about 2 seconds?
SAT133K
YesorNo
Ye s©GO TO 2.
No©Go to ª1. O/D OFF Indicator Lamp Does Not Come Onº, AT-218.
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Diagnostic Procedure Without CONSULT-II (Cont'd)
AT-47