ECO mode INFINITI QX4 2005 Factory Service Manual

TROUBLE DIAGNOSIS
SRS-33
C
D
E
F
G
I
J
K
L
MA
B
SRS
Revision: October 20052005 QX56
14. Repair the system as outlined by the “Repair order” in “Intermittent Malfunction Diagnostic Code Chart”,
that corresponds to the self-diagnostic result. For replacement procedure of component parts, refer to the
Removal and Installation procedure for the appropriate component.
15. Go to SRS-28, "
DIAGNOSTIC PROCEDURE 3" , for final checking.
CONSULT-II Diagnostic Code Chart ("SELF-DIAG [PAST]" or "TROUBLE DIAG RECORD")
Diagnostic item ExplanationRepair order
Recheck SRS at each replacement
NO DTC IS DETECTEDWhen malfunction is
indicated by the “AIR
BAG” warning lamp in
User mode.

Low battery voltage (Less than
9V)
Go to SRS-28, "DIAGNOSTIC PRO-
CEDURE 3" .

Self-diagnostic result “SELF-DIAG
[PAST]” (previously stored in the
memory) might not be erased
after repair.

Intermittent malfunction has been
detected in the past.

Go to SRS-31, "DIAGNOSTIC PRO-
CEDURE 4 (CONTINUED FROM
DIAGNOSTIC PROCEDURE 2)" .

Go to SRS-31, "DIAGNOSTIC PRO-
CEDURE 5" .

No malfunction is detected. —
DRIVER AIRBAG MODULE
[OPEN]
[B1049] or [B1054]

Driver air bag module circuit is open (including the spiral
cable).1. Visually check the wiring harness
connection.
2. Replace the harness if it has visible
damage.
3. Replace driver air bag module.
4. Replace the spiral cable.
5. Replace the air bag diagnosis sen-
sor unit.
6. Replace the related harness. DRIVER AIRBAG MODULE
[VB-SHORT]
[B1050] or [B1055]

Driver air bag module circuit is shorted to some power sup-
ply circuit (including the spiral cable).
DRIVER AIRBAG MODULE
[GND-SHORT]
[B1051] or [B1056]

Driver air bag module circuit is shorted to ground (including
the spiral cable).
DRIVER AIRBAG MODULE
[SHORT]
[B1052] or [B1057]

Driver air bag module circuits are shorted to each other.
ASSIST A/B MODULE
[OPEN]
[B1065] or [B1070]

Front passenger air bag module circuit is open. 1. Visually check the wiring harness
connection.
2. Replace the harness if it has visible
damage.
3. Replace front passenger air bag
module.
4. Replace the air bag diagnosis sen-
sor unit.
5. Replace the related harness. ASSIST A/B MODULE
[VB-SHORT]
[B1066] or [B1071]

Front passenger air bag module circuit is shorted to some
power supply circuit.
ASSIST A/B MODULE
[GND-SHORT]
[B1067] or [B1072]

Front passenger air bag module circuit is shorted to
ground.
ASSIST A/B MODULE
[SHORT]
[B1068] or [B1073]

Front passenger air bag module circuits are shorted to
each other.
CRASH ZONE SEN
[UNIT FAIL]
[B1033] or [B1034]
CRASH ZONE SEN
[COMM FAIL]
[B1035]

Crash zone sensor 1. Visually check the wiring harness
connection.
2. Replace the harness if it has visible
damage.
3. Replace the crash zone sensor.
4. Replace the air bag diagnosis sen-
sor unit.
5. Replace the related harness.

SRS-38
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
Trouble Diagnosis Without CONSULT-IIEHS0016U
DIAGNOSTIC PROCEDURE 6
Inspect SRS Malfunction Using "AIR BAG" Warning Lamp—Diagnosis Mode
NOTE:
SRS will not enter Diagnosis mode if no malfunction is detected in User mode.
1. Turn ignition switch ON.
2. After “AIR BAG” warning lamp lights for 7 seconds, turn ignition switch OFF within 1 second.
3. Wait more than 3 seconds.
4. Repeat steps 1 to 3 two more times (3 times total).
5. Turn ignition switch ON.
SRS is now in Diagnosis mode.
"AIR BAG" warning lamp operates in Diagnosis mode as follows:

ALL-MODE 4WD SYSTEM
TF-17
C
E
F
G
H
I
J
K
L
MA
B
TF
Revision: October 20052005 QX56
Ta b l e 1
Ta b l e 2
*: After 2.5 seconds have elapsed.

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 SWITCH

The wait detection switch operates when there is “circulating” torque produced in the propeller shaft
(L→H) or when there is a phase difference between 2-4 sleeve and clutch drum (H→L). After the release
of the “circulating” torque, the wait detection switch helps provide the 4WD lock gear (clutch drum) shifts.
A difference may occur between the operation of the 4WD shift switch and actual drive mode. At this
point, the wait detection switch senses an actual drive mode.

The wait detection switch operates as follows.
–4WD lock gear (clutch drum) locked: ON
–4WD lock gear (clutch drum) released: OFF

The wait detection switch senses an actual drive mode and the 4WD shift indicator lamp indicates the
vehicle drive mode.
NEUTRAL-4LO SWITCH
The neutral-4LO switch detects that transfer gear is in neutral or 4LO (or shifting from neutral to 4LO) condi-
tion by L-H shift fork position.
ATP SWITCH
ATP switch detects if transfer gear is in a neutral condition by L-H shift fork position.
NOTE:
Transfer gear may be in a neutral condition in 4H-4LO.
2-4WD SHIFT SOLENOID VALVE
The 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.
CLUTCH PRESSURE SOLENOID VALVE
The clutch pressure solenoid valve distributes torque (front and rear) in AUTO mode.
PNP switch “R” position VFF (Vehicle speed) A/T position Motor relay drive command
ON — R ON
OFF0Positions other than the “P” or
“N” positionsON
—“P” or “N” position (See Table
2.)—
0 < VFF ≤ 50 km/h (31 MPH) — ON
50 km/h (31 MPH) < VFF < 55
km/h (34 MPH)—HOLD
55 km/h (34 MPH) ≤ VFF — OFF
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)OFF* HOLD ON
ON — OFF* HOLD ON
P — — OFF* HOLD ON

TF-18
ALL-MODE 4WD SYSTEM
Revision: October 20052005 QX56
LINE PRESSURE SWITCH

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.

The line pressure switch turns ON when line pressure is produced.

The line pressure switch senses line pressure abnormalities and turns the 4WD warning lamp ON.
CLUTCH PRESSURE SWITCH

The clutch pressure switch determines whether or not adequate clutch pressure has built up under differ-
ent operating conditions.

The clutch pressure switch turns ON when clutch pressure is produced.

The clutch pressure switch senses clutch pressure abnormalities and turns the 4WD warning lamp ON.
TRANSFER FLUID TEMPERATURE SENSOR
The transfer temperature sensor detects the transfer fluid temperature and sends a signal to the transfer con-
trol unit.
TRANSFER CONTROL UNIT

Transfer control unit controls transfer control device by input signals of each sensor and each switch.

Self-diagnosis can be done.
TRANSFER CONTROL DEVICE
The transfer control device changes the state of transfer assembly between 2WD, AUTO, 4H⇔4LO with the
2WD, AUTO, 4H and 4LO signals of 4WD shift switch.
NOTE:

To shift between 4H⇔4LO, stop the vehicle, depress the brake pedal and shift the transmission selector
to the "N" position. Depress and turn the 4WD shift switch. The shift switch will not shift to the desired
mode if the transmission is not in "N" or the vehicle is moving. The 4LO indicator lamp will be lit when the
4LO is engaged.

Actuator motor and actuator position switch are integrated.
4WD SHIFT SWITCH AND INDICATOR LAMP
4WD Shift Switch
The 4WD shift switch allows selection from 2WD, AUTO, 4H or 4LO.
4WD Shift Indicator Lamp

Displays driving conditions selected by 4WD shift switch with 2WD, AUTO and 4H indicators while engine
is running. (When 4WD warning lamp is turned on, all 4WD shift indicator lamps are turned off.)

Turns ON for approximately 1 second when ignition switch is turned ON, for purpose of lamp check.
4LO Indicator Lamp

Displays 4LO condition while engine is running. 4LO indicator lamp flashes if transfer gear does not shift
completely under 2WD, AUTO, 4H⇔4LO. (When 4WD warning lamp is turned on, 4LO indicator lamp is
turned off.)

Turns ON for approximately 1 second when ignition switch is turned ON, for purpose of lamp check.

ALL-MODE 4WD SYSTEM
TF-19
C
E
F
G
H
I
J
K
L
MA
B
TF
Revision: October 20052005 QX56
4WD WARNING LAMP
Turns ON or FLASH when there is a malfunction in 4WD system.
Also turns ON when ignition switch is turned ON, for purpose of lamp check. Turns OFF for approximately 1
second after the engine starts if system is normal.
4WD Warning Lamp Indication
*: When 4WD warning lamp is ON, all the 4WD shift indicator lamps turn OFF.
AT P WA R N I N G L A M P
Even if A/T selector lever is in “P” position, vehicle may move because A/T parking mechanism does not oper-
ate when transfer is under neutral condition. ATP warning lamp is turned on so as to indicate this condition to
the driver.
System DiagramEDS002HB
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 “OFF” 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 “OFF”.Flickers once every 2 sec-
onds.
High fluid temperature in transfer unitWhen fluid temperature is high or fluid temperature sensor cir-
cuit 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
WDIA0164E

TF-20
ALL-MODE 4WD SYSTEM
Revision: October 20052005 QX56
COMPONENTS FUNCTION
CAN CommunicationEDS002HC
SYSTEM DESCRIPTION
Refer to LAN-5, "CAN COMMUNICATION" .
Component parts Function
Transfer control unit Controls transfer control device and control valves.
Transfer control device Actuator motor and actuator position switch are integrated so as to switch driving types.
2-4WD shift solenoid valve Controls oil pressure and allows selection between 2WD and 4WD.
Clutch pressure solenoid valve Controls oil pressure and distributes torque (front and rear).
Line pressure switch Detects line pressure.
Clutch pressure switch Detects clutch pressure.
Transfer fluid temperature sen-
sorDetects transfer fluid temperature.
Wait detection switch Detects whether or not 4WD lock gear is locked.
Neutral-4LO switch Detects that transfer is under neutral-4LO condition (or shifting through neutral).
ATP switch Detects that transfer is under neutral condition.
4WD shift switch Allows selection from 2WD, AUTO, 4H or 4LO.
4WD warning lamp

Illuminates if malfunction is detected in electrical system of 4WD system.

There is 1 blink every 2 seconds if rotation difference of front wheels and rear wheels is large.

There is 2 blinks every 1 second if high transfer fluid temperature is detected.
ATP warning lampIndicates that A/T parking mechanism does not operate when A/T selector lever is in “P” position
and transfer is under neutral condition.
4WD shift indicator lamp Displays driving condition selected by 4WD shift switch.
4LO indicator lamp Displays 4LO condition.
ABS actuator and electric unit
(control unit)Transmits vehicle speed signal via CAN communication to transfer control unit.
TCMTransmits the following signals via CAN communication to transfer control unit.

Output shaft revolution signal

A/T position indicator signal (PNP switch signal)
ECMTransmits the following signals via CAN communication to transfer control unit.

Engine speed signal

Accelerator pedal position signal

TROUBLE DIAGNOSIS
TF-35
C
E
F
G
H
I
J
K
L
MA
B
TF
Revision: October 20052005 QX56
NOTE:

Light tight-corner braking symptom may occur depending on driving conditions in AUTO mode. This is not
a malfunction.

Heavy tight-corner braking symptom occurs when vehicle is driven in the following conditions: 4WD shift
switch is "4H" or "4LO", steering wheel is turned fully to either side.
4WD shift indicator lamp or 4LO indicator
lamp does not changeEngine running4WD shift switch
TF-123
Wait detection switch
Neutral-4LO switch
ATP switch
2-4WD solenoid
Transfer control device
Actuator motor
Actuator position switch
Transfer inner parts
ATP warning lamp turns ON Engine runningCAN communication line
TF-125
4WD shift switch
PNP switch signal
ATP switch
Combination meter
Transfer inner parts
4LO indicator lamp repeats flashing Engine runningWait detection switch
TF-127
Neutral-4LO switch
Transfer inner parts
4WD warning lamp flashes rapidly (2 times/
second)While drivingTransfer fluid temperature
TF-128
Tire size is different between front and
rear of vehicle
4WD warning lamp flashes slowly
(1 time/2 seconds)While drivingTire size is different between front and
rear of vehicle.
TF-129
Transfer fluid temperature
Clutch pressure switch
Heavy tight-corner braking symptom occurs
(See NOTE.)

While driving

AUTO mode

Steering wheel is
turned fully to either
sideCAN communication line
TF-130
4WD shift switch
Accelerator pedal position signal
Clutch pressure solenoid
Transfer inner parts
4WD system does not operate While driving4WD shift switch
TF-131
Clutch pressure switch
Transfer inner parts Symptom Condition Check item Reference page

TF-48
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
P POSI SW AT [ON/OFF]זדP” position signal of A/T PNP switch status is
displayed.
Signal input with CAN communication line.
ABS OPER SW [ON/OFF]×–×ABS operation signal status is displayed.
Signal input with CAN communication line.
VDC OPER SW [ON/OFF]×–×VDC operation signal status is displayed.
Signal input with CAN communication line.
TCS OPER SW [ON/OFF]×–×TCS operation signal status is displayed.
Signal input with CAN communication line.
THROTTLE POSI [0.0/8] –××Thottle position status is displayed.
Signal input with CAN communication line.
4WD MODE [AUTO/LOCK/2WD/4L] –××Control status of 4WD recognized by transfer
control unit. (AUTO, 4H, 2WD or 4LO)
VHCL/S COMP [km/h] or [mph] –××Vehicle speed recognized by transfer control
unit.
COMP CL TORQ [kgm] –××Calculated torque recognized by transfer
control unit.
DUTY SOLENOID [%] –××Control value of clutch pressure solenoid.
2-4WD SOL [ON/OFF] –××Output condition to 2-4WD solenoid.
2-4WD SOL MON [ON/OFF] – –×Check signal for transfer control unit signal
output.
MOTOR RELAY [ON/OFF] –××Transfer motor relay signal status is dis-
played.
MOTOR RELAY MON [ON/OFF] – –×Check signal for transfer control unit signal
output.
4WD FAIL LAMP [ON/OFF] –××Control status of 4WD warning lamp is dis-
played.
2WD IND [ON/OFF] – –×Control status of 4WD shift indicator lamp
(2WD indicator lamp) is displayed.
AUTO IND [ON/OFF] – –×Control status of 4WD shift indicator lamp
(2WD and AUTO indicator lamp) is displayed.
LOCK IND [ON/OFF] – –×Control status of 4WD shift indicator lamp
(2WD, AUTO and Lock indicator) is dis-
played.
4L IND [ON/OFF] – –×Control status of 4LO indicator lamp is dis-
played.
ATP IND [ON/OFF] – –×Control status of ATP warning lamp is dis-
played.
SHIFT POS SW1 [ON/OFF]×–×Actuator position switch 1 (Low) signal status
is displayed.
SHIFT POS SW2 [ON/OFF]×–×Actuator position switch 2 (high) signal status
is displayed.
SHIFT ACT1 [ON/OFF] –××Output condition to actuator motor (clock-
wise)
SHIFT AC MON1 [ON/OFF]×–×Check signal for transfer control unit signal
output
SHIFT ACT2 [ON/OFF] –××Output condition to actuator motor (counter-
clockwise)
SHIFT AC MON2 [ON/OFF]×–×Check signal for transfer control unit signal
output Monitored item (Unit)Monitor item selection
Remarks
ECU INPUT
SIGNALSMAIN
SIGNALSSELEC-
TION FROM
MENU

TROUBLE DIAGNOSIS FOR SYSTEM
TF-57
C
E
F
G
H
I
J
K
L
MA
B
TF
Revision: October 20052005 QX56
COMPONENT INSPECTION
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Remove transfer shut off relay. Refer to TF-22, "
Location of Electrical Parts" .
3. Apply 12V direct current between transfer shut off relay termi-
nals 1 and 2.
4. Check continuity between relay terminals 3 and 5.
5. If NG, replace the transfer shut off relay. Refer to TF-22, "
Loca-
tion of Electrical Parts" .
Transfer Control UnitEDS002I5
DIAGNOSTIC PROCEDURE
1. INSPECTION START
Do you have CONSULT-II?
YES or NO
YES >> GO TO 2.
NO >> GO TO 3.
2. PERFORM SELF-DIAGNOSIS (WITH CONSULT-II)
With CONSULT-II
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “SELF-DIAG RESULTS” mode for “ALL MODE AWD/4WD” with CONSULT-II.
3. Touch “ERASE”.
4. Turn ignition switch “OFF” and wait at least 10 seconds.
5. Perform the self-diagnosis again.
Is the
“CONTROL UNIT 1 [P1802]”, “CONTROL UNIT 2 [P1803]”, “CONTROL UNIT 3 [P1804]” or “CONTROL
UNIT 4 [P1809]” displayed?
YES >> Replace transfer control unit. Refer to TF-132, "Removal and Installation" .
NO >> Inspection End.
3. PERFORM SELF-DIAGNOSIS (WITHOUT CONSULT-II)
Without CONSULT-II
1. Perform the self-diagnosis and then erase self-diagnostic results. Refer to TF-50, "
SELF-DIAGNOSTIC
PROCEDURE (WITHOUT CONSULT-II)" and TF-53, "ERASE SELF-DIAGNOSIS" .
2. Perform the self-diagnosis again.
Do the self-diagnostic results indicate AD converter?
YES >> Replace transfer control unit. Refer to TF-132, "Removal and Installation" .
NO >> Inspection End.
Condition Continuity
12V direct current supply between terminals 1 and 2 Yes
OFF No
SCIA1245E

TF-60
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
DIAGNOSTIC PROCEDURE
1. CHECK 4LO POSITION SWITCH SIGNAL
With CONSULT-II
1. Start engine.
2. Select “DATA MONITOR” mode for “ALL MODE AWD/4WD” with CONSULT-II.
3. Read out the value of “N POSI SW TF”.
Without CONSULT-II
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminal and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 2.
2. CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND NEUTRAL-4LO SWITCH
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and the neutral-4LO switch harness connector.
3. Check continuity between transfer control unit harness connec-
tor E143 terminal 25 (V) and neutral-4LO switch harness con-
nector F60 terminal 13 (V).
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
Condition Display value

Vehicle stopped

Engine running

A/T selector lever “N” position

Brake pedal depressed4WD shift switch: 2WD,
AUTO or 4HOFF
4WD shift switch: 4H to
4LO (While actuator
motor is operating.)OFF → ON
4WD shift switch: 4LO to
4H (While actuator motor
is operating.)ON → OFF
4WD shift switch: 4LO ON
SDIA2692E
ConnectorTe r m i n a l
(Wire
color)ConditionVoltage
(Approx.)
E143 25 (V) -
Ground

Vehicle stopped

Engine running

A/T selector lever
“N” position

Brake pedal
depressed4WD shift switch:
2WD, AUTO or 4HBattery
voltage
4WD shift switch: 4H
to 4LO (While actuator
motor is operating.)Battery
voltage
→ 0V
4WD shift switch: 4LO
to 4H (While actuator
motor is operating.)0V →
Battery
voltage
4WD shift switch: 4LO 0V
SDIA2693E
Continuity should exist.
SDIA2694E