Transfer INFINITI QX4 2001 Factory Workshop Manual

Supplemental Restraint System (SRS) ªAIR
BAGº and ªSEAT BELT PRE-TENSIONERº
NBTF0001The Supplemental Restraint System such as ªAIR BAGº and ªSEAT BELT PRE-TENSIONERº used along with
a seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain types of
collision. The SRS system composition which is available to INFINITI QX4 is as follows:
IFor a frontal collision
The Supplemental Restraint System consists of driver air bag module (located in the center of the steer-
ing wheel), front passenger air bag module (located on the instrument panel on passenger side), seat belt
pre-tensioners, a diagnosis sensor unit, warning lamp, wiring harness and spiral cable.
IFor a side collision
The Supplemental Restraint System consists of side air bag module (located in the outer side of front seat),
satellite sensor, diagnosis sensor unit (one of components of air bags for a frontal collision), wiring harness,
warning lamp (one of components of air bags for a frontal collision).
Information necessary to service the system safely is included in theRSsection of this Service Manual.
WARNING:
ITo avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be performed
by an authorized INFINITI dealer.
IImproper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the RS section.
IDo not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. Spiral cable and wiring harnesses covered with yellow insulation tape either just
before the harness connectors or for the complete harness are related to the SRS.
SEF289H
PrecautionsNBTF0092IBefore connecting or disconnecting the Transfer control
unit harness connector, turn ignition switch OFF and dis-
connect negative battery terminal. Failure to do so may
damage the Transfer control unit. Because battery voltage
is applied to Transfer control unit even if ignition switch
is turned off.
SEF291H
IWhen connecting or disconnecting pin connectors into or
from Transfer control unit, take care not to damage pin
terminals (bend or break).
Make sure that there are not any bends or breaks on
Transfer control unit pin terminal, when connecting pin
connectors.
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PRECAUTIONS
Supplemental Restraint System (SRS) ªAIR BAGº and ªSEAT BELT PRE-TENSIONERº
TF-3

MEF040DB
IBefore replacing Transfer control unit, perform Transfer
control unit input/output signal inspection and make sure
whether Transfer control unit functions properly or not.
(See page TF-55.)
Service NoticeNBTF00021) Before proceeding with disassembly, thoroughly clean the outside of the all-mode 4WD transfer. It is
important to prevent the internal parts from becoming contaminated by dirt or other foreign matter.
2) Disassembly should be done in a clean work area.
3) Use lint-free cloth or towels for wiping parts clean. Common shop rags can leave fibers that could inter-
fere with the operation of the all-mode 4WD transfer.
4) Place disassembled parts in order for easier and proper assembly.
5) All parts should be carefully cleaned with a general purpose, non-flammable solvent before inspection or
reassembly.
6) Gaskets, seals and O-rings should be replaced any time the all-mode 4WD transfer is disassembled.
7) It is very important to perform functional tests whenever they are indicated.
8) The valve body contains precision parts and requires extreme care when parts are removed and serviced.
Place removed parts in a parts rack in order to replace them in correct positions and sequences. Care will
also prevent springs and small parts from becoming scattered or lost.
9) Properly installed valves, sleeves, plugs, etc. will slide along bores in valve body under their own weight.
10) Before assembly, apply a coat of recommended ATF to all parts. Apply petroleum jelly to protect O-rings
and seals, and to hold bearings and washers in place during assembly. Do not use grease.
11) Extreme care should be taken to avoid damage to O-rings, seals and gaskets when assembling.
12) After overhaul, refill the transfer with new ATF.
13) When the all-mode 4WD transfer drain plug is removed, only some of the fluid is drained. Old all-mode
4WD transfer fluid will remain in torque converter and ATF cooling system. Always follow the procedures,
MA-22, ªChanging All-mode 4WD Transfer Fluidº.
Wiring Diagrams and Trouble DiagnosisNBTF0003When you read wiring diagrams, refer to the following:
IGI-11, ªHOW TO READ WIRING DIAGRAMSº
IEL-9, ªPOWER SUPPLY ROUTINGº
When you perform trouble diagnosis, refer to the following:
IGI-35, ªHOW TO FOLLOW TEST GROUPS IN TROUBLE DIAGNOSISº
IGI-24, ªHOW TO PERFORM EFFICIENT DIAGNOSIS FOR AN ELECTRICAL INCIDENTº
PRECAUTIONS
Precautions (Cont'd)
TF-4

Tool number
(Kent-Moore No.)
Tool nameDescription
KV40105500
(Ð)
Support
NT667
Installing planetary carrier assembly
a: 69 mm (2.72 in) dia.
b: 52 mm (2.05 in) dia.
c: 120 mm (4.72 in) dia.
KV38100200
(Ð)
Drift
NT673
Installing transfer cover oil seal
a: 65 mm (2.56 in) dia.
b: 49 mm (1.93 in) dia.
KV31103300
(Ð)
Drift
NT668
Removing and installing press flange snap ring
a: 76.3 mm (3.004 in) dia.
b: 130 mm (5.12 in)
KV31103400
(Ð)
Clutch piston attachment
1 Shaft-drift
2 Guide-cylinder
NT669
Installing clutch piston
a: 88.5 mm (3.484 in) dia.
b: 158 mm (6.22 in) dia.
ST33290001
(J25810-A)
Puller
NT414
Removing center case oil seal
Removing rear oil seal
a: 250 mm (9.84 in)
b: 160 mm (6.30 in)
ST33051001
(J22888)
Puller
NT824
Removing companion flange
a: 135 mm (5.31 in)
b: 100 mm (3.94 in)
c: 170 mm (6.69 in)
PREPARATION
Special Service Tools (Cont'd)
TF-8

ALL-MODE 4WD TRANSFER BASIC CONTROLNBTF0007S01
SMT043D
HYDRAULIC CONTROL CIRCUITSNBTF0007S02
SMT040D
OUTLINENBTF0007S03All-mode 4WD transfer is controlled by the transfer control unit and
sensors.
If a malfunction occurs in the all-mode 4WD system, the 4WD
warning lamp lights up to indicate the system malfunction. There
are two ways to identify the cause of the malfunction.
1) Performing the self-diagnosis. (The 4WD warning lamp will
indicate what kind of malfunction has occurred by flickering.)
2) Performing diagnosis using CONSULT-II.
ALL-MODE 4WD SYSTEM
Control System (Cont'd)
TF-12

CONTROL SYSTEM DIAGRAMNBTF0007S04
SMT763D
INDICATIONS OF 4WD WARNING LAMPNBTF0007S05
Condition Content 4WD warning lamp
During self-diagnosis Indicates the malfunction position by number of flickers. Flickers at malfunction mode.
Lamp check*Checks the lamp by turning ON during engine starting. After
engine starts, it turns OFF if there are no malfunctions.ON
Malfunction in 4WD system*Turns ON to indicate malfunction. When ignition switch is
turned to ªOFFº or the malfunction is corrected, it turns OFF.ON
When vehicle is driven with different
diameters of front and rear tiresFlickers once every 2 seconds.
Turns OFF when ignition switch is ªOFFº.Flickers once every 2 sec-
onds.
High fluid temperature in transfer
unitWhen fluid temperature is high or fluid temperature sensor
circuit is shorted, it flickers twice every second.
It turns OFF when fluid temperature becomes normal.Flickers twice a second.
Other than above (System is nor-
mal.)Lamp is OFF. OFF
*: When 4WD warning lamp is ON, all the 4WD shift indicator lamps turn OFF.
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ALL-MODE 4WD SYSTEM
Control System (Cont'd)
TF-13

Description of Electrical PartsNBTF0067TRANSFER MOTORNBTF0067S011. The transfer motor drives the sub-oil pump to provide proper lubrication and oil pressure control when the
vehicle is at standstill, during low-speed operations or is being driven in reverse.
2. The main oil pump is operated by the driving force of the mainshaft. In other words, sufficient oil pressure
buildup does not occur when the vehicle is at standstill or during low-speed operations. While the vehicle
is being driven in reverse, the main oil pump rotates in the reverse direction. Therefore the main oil pump
does not discharge oil pressure. During any of the above vehicle operations, the transfer motor drives the
sub-oil pump to compensate for insufficient oil pressure.
3. The transfer motor operates as follows:
1) The motor relay turns OFF in the 2WD mode.
2) The motor relay operates as described in the table below in modes other than the 2WD mode.
Table 1
PNP switch ªRº position VFF (Vehicle speed) A/T position Motor relay drive command
ON Ð R ON
OFF0 km/hPositions other than the ªPº or
ªNº positionsON
ЪPº or ªNº position (See Table
2.)Ð
0 < VFF%30 km/h Ð ON
30 < VFF < 35 km/h Ð HOLD
35 km/h%VFF Ð OFF
Table 2
A/T position N-4L SW 4WD modeThrottle position
0 - 0.07/8 0.07/8 - 1/8 1/8 - MAX
NOFFLOCK (4H) ON ON ON
Positions other than
the LOCK position
(2WD or AUTO)See NOTE. HOLD ON
ON Ð See NOTE. HOLD ON
P Ð Ð See NOTE. HOLD ON
NOTE:
OFF (after 2.5 seconds have elapsed.)
4. 4WD shift switch, PNP switch, Neutral-4LO switch, vehicle speed sensor and throttle position sensor are
used in conjunction with the transfer motor.
WAIT DETECTION SWITCHNBTF0067S021. The wait detection switch releases the ªboomingº torque produced in the propeller shaft. After the release
of the ªboomingº torque, the wait detection switch helps provide the 4WD lock gear (clutch drum) shifts.
A difference may occur between the operation (ª4LOº to ª4Hº shift only) of the 4WD shift switch and actual
drive mode. At this point, the wait detection switch senses an actual drive mode.
2. The wait detection switch operates as follows:
4WD lock gear (clutch drum) locked: ON
4WD lock gear (clutch drum) released: OFF
3. The wait detection switch senses an actual drive mode and the 4WD shift indicator lamp indicates the
vehicle drive mode.
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ALL-MODE 4WD SYSTEM
Description of Electrical Parts
TF-15

2-4WD SHIFT SOLENOID VALVENBTF0067S03The 2-4WD shift solenoid valve operates to apply oil pressure to the wet, multiplate clutch, depending on the
drive mode. The driving force is transmitted to the front wheels through the clutch so the vehicle is set in the
4WD mode. Setting the vehicle in the 2WD mode requires no pressure buildup. In other words, pressure force
applied to the wet, multiplate clutch becomes zero.
LINE PRESSURE SWITCHNBTF0067S041. With the transfer system design, control of the oil pressure provides the transmission of drive torque to
the front wheels. The main pressure to control the oil pressure is referred to as the line pressure.
The line pressure switch determines whether or not adequate line pressure has built up under different
operating conditions.
2. The line pressure switch turns ON when line pressure is produced.
3. The line pressure switch senses line pressure abnormalities and turns the 4WD warning lamp ON.
ALL-MODE 4WD SYSTEM
Description of Electrical Parts (Cont'd)
TF-16

INDICATIONS OF 4WD WARNING LAMPNBTF0011S03
Flickering pattern or flick-
ering conditionMalfunction Check items
1 Front revolution sensor circuit is shorted or open.Revolution sensor (front) circuit,
TF-61.
2 Rear revolution sensor circuit is shorted or open.Revolution sensor (rear) [Refer to
AT-111, ªDTC P0720 Vehicle Speed
Sensor´A/T (Revolution sensor)º.]
3 4WD solenoid valve circuit is shorted or open. 4WD solenoid valve circuit, TF-64.
42-4WD shift solenoid valve circuit is shorted or 2WD switch of
4WD shift switch is shorted.2-4WD shift solenoid valve circuit or
4WD shift switch circuit, TF-66.
5 Transfer motor relay circuit is shorted or open. Transfer motor relay circuit, TF-70.
8Power supply voltage of throttle position sensor is improper. Or
A/D converter of transfer control unit functions improperly.Throttle position sensor (Refer to
AT-176, ªDTC P1705 Throttle Posi-
tion Sensorº.)
9 Transfer fluid temperature sensor circuit is open.Transfer fluid temperature sensor
circuit, TF-73.
10 Neutral-4LO switch circuit is shorted or open. Neutral-4LO switch circuit, TF-76.
112-4WD shift solenoid valve circuit, 2WD switch of 4WD shift
switch circuit or clutch pressure switch circuit is shorted or open.2-4WD shift solenoid valve circuit,
4WD shift switch circuit or clutch
pressure switch circuit, TF-66, 80.
12 Line pressure switch circuit is shorted or open. Line pressure switch circuit, TF-83.
13 Engine speed signal circuit is shorted or open.Engine speed signal (Refer to
AT-116, ªDTC P0725 Engine Speed
Signalº.)
14 Throttle position sensor circuit is shorted or open.Throttle position sensor (Refer to
AT-176, ªDTC P1705 Throttle Posi-
tion Sensorº.)
15 Failure in power supply circuit of transfer control unit. Power supply of transfer control unit
16 4WD shift switch circuit is shorted. 4WD shift switch circuit, TF-66.
17 ABS operation signal circuit is shorted. ABS operation signal circuit, TF-86.
18ATP switch, wait detection switch or neutral-4LO switch circuit is
shorted or open.ATP switch, wait detection switch or
neutral-4LO switch circuit*, TF-76.
19Transfer control device actuator motor is faulty. (Abnormalities
are detected when actuator motor fails to operate while shifting
from ª4Hº to ª4LOº or vice versa.)Actuator motor and motor circuit,
TF-115, 89.
20Transfer control device actuator motor arm position sensing
switch is faulty.Actuator motor arm position sensing
switch and sensing switch circuit,
TF-115, 92.
21Transfer control device actuator circuit is faulty (Abnormalities
are detected when motor relay circuit is open/shorted or relay
monitor circuit is open/shorted.)Actuator motor, actuator motor arm
position sensing switch and their
associated circuits, TF-114, 115 and
94.
Repeats flickering every
2 to 5 sec.Circuits that the self-diagnosis covers have no malfunction. Ð
Repeats flickering every
0.25 sec.IPower supply failure of memory back-up.
IBattery is disconnected for a long time.
IBattery performance is poor.Data erase/display circuit, TF-88.GI
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Trouble Diagnosis without CONSULT-II (Cont'd)
TF-29

SMT965D
6. Touch ªSELF-DIAG RESULTSº on SELECT DIAG MODE
screen.
SMT966D
7. Self-diagnostic results are displayed.
SELF-DIAGNOSTIC ITEMSNBTF0012S02
Detected items
(Screen terms for CONSULT-II,
ªSELF-DIAG RESULTº mode)Malfunction is detected when... Check items
Revolution sensor (front) (Note 3)
(VHCL SPEED SEN´FR)IFront revolution sensor (installed on T/F) signal is not
input due to open circuit.
IImproper signal is input while driving.Revolution sensor (front) circuit,
TF-61.
Revolution sensor (rear)
(VHCL SPEED SEN´RR)ISignal from vehicle speed sensor 1 (installed on A/T)
is not input due to open circuit.
IImproper signal is input while driving.Revolution sensor (rear) [Refer to
AT-111, ªDTC P0720 Vehicle Speed
Sensor´A/T (Revolution sensor)º.]
4WD solenoid valve
(DUTY SOLENOID)
IProper voltage is not applied to solenoid valve due to
open or short circuit.4WD solenoid valve, TF-64.
2-4WD shift solenoid valve
(2-4WD SOLENOID)2-4WD shift solenoid valve or
4WD shift switch circuit, TF-66.
Transfer motor relay
(MOTOR RELAY)IMotor does not operate properly due to open or short
circuit in transfer motor or motor relay.Transfer motor relay circuit,
TF-70.
Transfer fluid temperature sensor
(FLUID TEMP SENSOR)ISignal voltage from fluid temperature sensor is abnor-
mally high (T/F fluid temperature is abnormally low)
while driving.Transfer fluid temperature sensor
circuit, TF-73.
Neutral-4LO switch
(N POSI SW TF)IImproper signal is input while driving. Neutral-4LO switch, TF-76.
Clutch pressure
(CLUTCH PRESSURE)IImproper signal is input due to open or short circuit.
IMalfunction occurs in clutch pressure hydraulic circuit.Clutch pressure switch circuit
(*1), TF-80.
Line pressure
(LINE PRESSURE)IImproper signal is input due to open or short circuit.
IMalfunction occurs in line pressure hydraulic circuit.Line pressure switch circuit (*1),
TF-83.
Engine speed signal (Note 1)
(ENGINE SPEED SIG)IEngine speed is abnormally low while driving.Engine speed signal (Refer to
AT-116, ªDTC P0725 Engine Speed
Signalº.)
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Trouble Diagnosis with CONSULT-II (Cont'd)
TF-31

Detected items
(Screen terms for CONSULT-II,
ªSELF-DIAG RESULTº mode)Malfunction is detected when... Check items
Throttle position sensor
(THRTL POSI SEN)ISignal voltage from throttle position sensor is abnor-
mally high.
ISignal voltage from throttle position sensor is abnor-
mally low when closed throttle position switch is OFF.Throttle position sensor (Refer to
AT-176, ªDTC P1705 Throttle
Position Sensorº.)
Transfer control unit (ADC)
C/U (ADC)/THRTL SENIPower supply voltage for throttle position sensor is
improper or A/D converter system of transfer control
unit is faulty.Throttle position sensor (Refer to
AT-176, ªDTC P1705 Throttle
Position Sensorº.)
Battery voltage (Note 1)
(BATTERY VOLTAGE)IPower supply voltage for transfer control unit is abnor-
mally low while driving.Power supply circuit (Refer to
AT-96, ªWiring Diagram Ð AT Ð
MAINº.)
4WD shift switch
(4WD MODE SW)IMore than two switch inputs are simultaneously
detected due to short circuit of 4WD shift switch.4WD shift switch circuit, TF-66.
ABS operation signal (Note 4)
(ABS OPER SIGNAL)IWhen a malfunction signal due to disconnection or
shorting is detected.
IWhen a defect signal is entered from the ABS control
unit.ABS operation signal circuit,
TF-86.
Wait detection switch (Note 2)
(WAIT DETECT SWITCH)IImproper signal is input due to open or short circuit.ATP switch, wait detection switch
and neutral-4LO switch circuits
(*2), TF-76.
Shift actuator abnormal
(SHIFT ACT)Transfer control device actuator motor is faulty. (Abnor-
malities are detected when actuator motor fails to oper-
ate while shifting from ª4Hº to ª4LOº or vice versa.)Actuator motor and motor circuit,
TF-115, 89.
Shift actuator position switch
abnormal
(SHIFT ACT P/S)Transfer control device actuator motor arm position sens-
ing switch is faulty.Actuator motor arm position
sensing switch and sensing
switch circuit, TF-115, 92.
Shift actuator circuit abnormal
(SHIFT ACT CIR)Transfer control device actuator circuit is faulty (Abnor-
malities are detected when motor relay circuit is open/
shorted or relay monitor circuit is open/shorted.)Actuator motor, actuator motor
arm position sensing switch and
their associated circuits, TF-114,
115 and 94.
Memory power supply stopIDue to removal of battery which cuts off power supply
to transfer control unit, self-diagnosis memory function
is suspended.Data erase/display circuit, TF-88.
Transfer control unit (RAM)
[CONTROL UNIT (RAM)]IFailure is detected in the memory (RAM) system of
transfer control unit.
Transfer control unit (ROM)
[CONTROL UNIT (ROM)]IFailure is detected in the memory (ROM) system of
transfer control unit.
Transfer control unit (EEPROM)
[CONTROL UNIT (EEPROM)]IFailure is detected in the memory (EEPROM) system
of transfer control unit.
Note 1: When a malfunction occurs, it is only displayed and not stored in the memory.
Note 2: When the wait detection switch has been properly fixed, malfunction information is erased from the memory.
Note 3: If 4WD shift switch is left between 4H and 4LO for a while, this indication may be displayed.
(*1): If the malfunction is detected only while driving in reverse, check the continuity of ªRº position on A/T PNP switch. When there is
nothing wrong with the electrical system, check the hydraulic system.
(*2): If a revolution sensor malfunction is detected at the same time, check the revolution sensor circuit first.
Note 4: When this malfunction is detected with the ABS warning lamp off, first check for disconnection or shorting in the harness between
the transfer control unit and the ABS control unit.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Trouble Diagnosis with CONSULT-II (Cont'd)
TF-32