2004 INFINITI QX56 4WD

ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
TF-39
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Revision: August 20072004 QX56
2-4WD shift solenoid valve
(2-4WD SOL)
2-4WD shift solenoid monitor
(2-4WD SOL MON)OFF
4WD shift switchIn “2WD” position
ON (“Wait” function is not oper-
ating.)
In “AUTO” position
OFF (“Wait” function is operat-
ing.)
ON (“Wait” function is not oper-
ating.)
In “4H” position
OFF (“Wait” function is operat-
ing.)
ON In “4LO” position
Battery voltage
(BATTERY VOLT)Approx. 12V Key switch “ON” and engine at rest
Approx. 13 - 14V During idling
AUTO switchOFF 4WD shift switch in other than “AUTO” position
ON 4WD shift switch in “AUTO” position
4L switchOFF 4WD shift switch in other than “4LO” position
ON 4WD shift switch in “4LO” position
N position switch
(N POSI SW AT)OFF A/T selector lever in other than “N” position
ON A/T selector lever in “N” position
R position switch
(R POSI SW AT)OFF A/T selector lever in other than “R” position
ON A/T selector lever in “R” position
P position switch
(P POSI SW AT)OFF A/T selector lever in other than “P” position
ON A/T selector lever in “P” position
Throttle opening
(THROTTLE POSI)0.0/8 - 8.0/8 Throttle fully closed (0.0/8) or throttle fully open (8.0/8) Indicated items
(Screen terms for CONSULT-II, “DATA
MONITOR” mode)Display Conditions

TF-40
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Revision: August 20072004 QX56
4WD-mode2WD
4WD shift
switchIn “2WD” position
AUTO In “AUTO” position
LOCK In “4H” position
4L In “4LO” position
Front wheel speed
(VHCL/S SEN-FR)0 - 255 km/h (0 - 158 MPH) 0 km/h (vehicle at standstill)
Rear wheel speed
(VHCL/S SEN-RR)0 - 255 km/h (0 - 158 MPH) 0 km/h (vehicle at standstill)
Shift ACTR operating 1
(SHIFT ACT 1)
Shift activating monitor 1
(SHIFT AC MON 1)OFF During normal operation
ON During shifts from “4H” to “4LO” position
Shift ACTR operating 2
(SHIFT ACT 2)
Shift activating monitor 2
(SHIFT AC MON 2)OFF During normal operation
ON During shifts from “4LO” to “4H” position
4WD fail lampOFF During normal operation
ONDuring 2-second period (after key switch turned to “ON”)
or when system is out of order
Shift ACTR position sensing switch 1
(SHIFT POS SW 1)OFF 4WD shift switch is in a position other than “4LO”.
ON 4WD shift switch in “4LO” position
Shift ACTR position sensing switch 2
(SHIFT POS SW 2)OFF 4WD shift switch in “4LO” position
ON 4WD shift switch is in a position other than “4LO”.
2WD indicator lamp
(2WD IND)OFF Engine at rest or system out of order
ON Except the above condition Indicated items
(Screen terms for CONSULT-II, “DATA
MONITOR” mode)Display Conditions

ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
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Revision: August 20072004 QX56
WORK SUPPORT
Purpose
When there is no problem with transfer and 4WD system, the following symptom in “AUTO” mode may be
claimed by a customer.

Vibration when accelerating on snow-covered or icy roads. (Note)
AUTO indicator lamp
(AUTO IND)OFFEngine at rest during 2WD-mode operation or system out
of order
ON 4WD shift switch in “4LO” or “4H” or “AUTO” position
LOCK indicator lamp
(LOCK IND)OFFEngine at rest and 4WD shift switch in “AUTO” position
during 2WD-mode operation or system out of order
ON 4WD shift switch in “4H” or “4LO” position
4LO indicator lamp
(4L IND)OFFEngine at rest and 4WD shift switch in “AUTO” position
during 2WD-mode operation or system out of order
ON 4WD shift switch in “4LO” position
Clutch force release limit
(CL/F RLS LIM)0.2, 0.3, 1.2 kgmIndicates the clutch force release setting applied using the
scan tool. 0.3 kgm is the default setting.
VDC operation switch
(VDC OPER SW)OFF VDC is not operating.
ON VDC is operating.
TCS operation switch
(TCS OPER SW)OFF TCS is not operating.
ON TCS is operating.
ATP indicator lamp
(ATP IND)OFF Normal operation.
ONDriver is attempting to shift into or out of 4L while the AT is
not in neutral.
Transfer case F speed
(T/F F SPEED)0.0 km/h (0.0 MPH) —
Automatic transmission R speed
(AT R SPEED)0.0 km/h (0.0 MPH) —
Automatic transmission gear position
(AT GEAR POSI)1,2,3,4 Displays actual AT gear position. Indicated items
(Screen terms for CONSULT-II, “DATA
MONITOR” mode)Display Conditions

TF-42
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Revision: August 20072004 QX56
It is possible to deal with these symptoms by changing “CLUTCH FORCE RELEASE LIMIT VALUE”.
However, be careful when changing the values because it may adversely affect driving performance.
NOTE:
A slight shock is felt at a few hertz as if it were being pushed lightly from behind.
CONSULT-II Setting Procedure
1. Turn ignition switch to “OFF” position.
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CON-
VERTER, malfunctions might be detected in self-diagnosis
depending on control unit which carry out CAN communication.
2. Connect CONSULT-II and CONSULT-II CONVERTER to data
link connector.
3. Turn ignition switch to “ON” position.
4. Touch “START (NISSAN BASED VHCL)”.
5. Touch “ALL MODE AWD/4WD”.
If "ALL MODE AWD/4WD" is not indicated, refer to GI-39,
"CONSULT-II Data Link Connector (DLC) Circuit" .
6. Touch “WORK SUPPORT”.
7. Select WORK ITEM by touching “CLUTCH/F RLS LIM ADJ”.
CLUTCH FORCE RELEASE LIMIT ADJUSTMENT
1.2 kg-m: Tight corner braking symptom is alleviated. However, vibration may occur when accelerating on a
low µ road (icy road, etc.).
0.3 kg-m: Initial set value
0.2 kg-m: Do not set to this value because the tight corner braking symptom will get worse.
1. Current CLUTCH FORCE RELEASE LIMIT value “0.3 kgm”
appears under “CONDITION SETTING” on CONSULT-II display.
2. Touch “1.2” on the display.
BCIA0029E
BCIA0031E
WDIA0085E
SMT968D

TF-44
TROUBLE DIAGNOSIS — INTRODUCTION
Revision: August 20072004 QX56
TROUBLE DIAGNOSIS — INTRODUCTIONPFP:00000
IntroductionEDS0017W
DESCRIPTION
When a malfunction (indicated by the 4WD warning lamp illumination) occurs, collect information first from the
customer about how the malfunction occurs. Then, proceed with the diagnosis presuming it is the cause. Also
inspect the electrical system, paying close attention to other possibilities such as fluid level and leaks.
All-mode 4WD transfer is controlled by transfer control unit and sensors.
If a malfunction occurs in the all-mode 4WD system, the 4WD warning lamp lights up to inform of 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.
DIAGNOSTIC WORKSHEET
Information from Customer
KEY POINTS

WHAT ..... Vehicle model

WHEN..... Date, Frequencies

WHERE..... Road conditions

HOW..... Operating conditions, Symptoms
Diagnostic Worksheet
Information sheet from customer
Customer name MR/MS Model & Year VIN
Transfer model
AT X 1 4 BEngine Mileage
Incident Date Manuf. Date In Service Date
Frequency❏ Continuous ❏ Intermittent ( times a day)
Symptoms❏ 4WD shift indicator lamp does not turn on.
❏ 4WD warning lamp does not turn on.
❏ 4WD shift indicator lamp does not turn off.
❏ ATP warning lamp does not turn on.
❏ 4LO indicator lamp does not turn on.
❏ 4WD shift indicator lamp does not indicate “4H”.
❏ 4WD shift indicator lamp repeats flicking.
❏ Tight corner braking symptom occurs.
❏ 4WD system does not operate.
❏ Others.
4WD warning lamp❏ Continuously lit❏ Not lit
1.❏ Listen to customer complaints.TF-47
2.❏ Check transfer fluid.TF-47
❏ Leakage
❏ Fluid condition
❏ Fluid level
3.❏ Road testingTF-47
❏ 1. Check before engine is started.
❏ 2. Check at idle.
❏ 3. Cruise test
4.❏ Perform self-diagnosis NG items (with CONSULT-II and without CONSULT-II).TF-31
, TF-28

TF-48
TROUBLE DIAGNOSIS — BASIC INSPECTION
Revision: August 20072004 QX56
1. CHECK BEFORE ENGINE IS STARTED
1. CHECK 4WD SHIFT INDICATOR LAMP
1. Park vehicle on flat surface.
2. Turn ignition switch to OFF position.
3. Move A/T selector lever to P position.
4. Set 4WD shift switch to 4H position.
5. Set 4WD shift switch to 2WD position.
6. Turn ignition switch to ON position. (Do not start engine.)
7. Does 4WD shift indicator lamp turn ON for approx. 1 second?
Ye s o r N o
Yes >> GO TO 2.
No >> Go to Symptom 1. Refer to TF-85, "
Symptom 1. 4WD
Shift Indicator Lamp Does Not Turn ON (Although the
ignition switch is turned ON, all the 4WD indicator lamps
do not turn ON for 1 second)" .
2. CHECK 4WD WARNING LAMP
Is 4WD warning lamp turned ON?
Ye s o r N o
Yes >> 1. Turn ignition switch to OFF position.
2. Perform self-diagnosis.
Refer to TF-27, "
Trouble Diagnosis without CON-
SULT-II" .
3. Go to “2. CHECK AT IDLE”. Refer to TF-49, "
2.
CHECK AT IDLE" .
No >> Go to Symptom 2. Refer to TF-87, "
Symptom 2. 4WD
Warning Lamp Does Not Turn ON (Although the ignition
switch is turned ON, the 4WD warning lamp does not
turn ON)" .
LDIA0061E
WDIA0071E
WDIA0071E

TROUBLE DIAGNOSIS — BASIC INSPECTION
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Revision: August 20072004 QX56
2. CHECK AT IDLE
1. CHECK 4WD SHIFT INDICATOR LAMP
1. Park vehicle on flat surface.
2. Turn ignition switch to OFF position.
3. Move A/T selector lever to P or N position.
4. Set 4WD shift switch to 4H position.
5. Set 4WD shift switch to 2WD position.
6. Start engine.
7. Is 4WD shift indicator lamp turned OFF?
Ye s o r N o
Yes >> Go to “ATP SWITCH, WAIT DETECTION SWITCH AND
NEUTRAL-4LO SWITCH”. Refer to TF-69, "
AT P
SWITCH, WAIT DETECTION SWITCH AND NEUTRAL-4LO SWITCH" .
No >> GO TO 2.
2. CHECK 4WD WARNING LAMP
Is 4WD warning lamp turned OFF?
Ye s o r N o
Yes >> GO TO 3.
No >> Perform self-diagnosis. Refer to TF-27, "
Trouble Diagnosis without CONSULT-II" .
WDIA0071E

TF-50
TROUBLE DIAGNOSIS — BASIC INSPECTION
Revision: August 20072004 QX56
3. CHECK 4WD SHIFT INDICATOR LAMP
1. Set 4WD shift switch to 2WD, AUTO, 4H, 4LO, 4H and 2WD in
order.
(Stay at each switch position for at least 1 second.)
2. Does 4WD shift indicator lamp change properly and does
buzzer sound?
Ye s o r N o
Yes >> GO TO 4.
No >> Go to “2-4WD SHIFT SOLENOID VALVE AND 4WD
SHIFT SWITCH”. Refer to TF-62, "
2-4WD SHIFT SOLE-
NOID VALVE AND 4WD SHIFT SWITCH" .
4. CHECK 4WD WARNING LAMP
Is 4WD warning lamp turned ON?
Ye s o r N o
Yes >> Perform self-diagnosis. Refer to TF-27, "Trouble Diagnosis without CONSULT-II" .
No >> GO TO 5.
LDIA0063E
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