2004 INFINITI QX56 check engine

SC-14
STARTING SYSTEM
Revision: August 20072004 QX56
DIAGNOSTIC PROCEDURE 1
Check Terminal "2" Circuit
1. CHECK POWER SUPPLY FOR STARTER MOTOR “2” TERMINAL
1. Remove the fuel pump fuse.
2. Crank or start the engine (where possible) until the fuel pressure is released.
3. Turn the ignition switch OFF.
4. Check that the starter motor connector F27 connection is clean and tight.
5. Check voltage between starter motor connector F27 terminal 2
(B/R) and ground using a digital circuit tester.
OK or NG
OK >> GO TO 2.
NG >> Check harness between the battery and the starter
motor for open circuit.
2. CHECK BATTERY CABLE CONNECTION QUALITY (VOLTAGE DROP TEST)
Check voltage between starter motor connector F27 terminal 2 (B/R)
and battery positive terminal using a digital circuit tester.
OK or NG
OK >> GO TO 3.
NG >> Check harness between the battery and the starter
motor for poor continuity.
3. CHECK STARTER MOTOR GROUND CIRCUIT (VOLTAGE DROP TEST)
Check voltage between starter motor case and battery negative ter-
minal using a digital circuit tester.
OK or NG
OK >> Starter motor “2” terminal circuit is OK. Further inspec-
tion is necessary. Refer to SC-13, "
WORK FLOW" .
NG >> Check harness between the starter motor case and
ground for poor continuity. Battery voltage should
exist.
WKIA2105E
Ignition switch in
START.: Less than 0.5V
WKIA2106E
Ignition switch in
START.: Less than 0.2V
WKIA2107E

STARTING SYSTEM
SC-15
C
D
E
F
G
H
I
J
L
MA
B
SC
Revision: August 20072004 QX56
DIAGNOSTIC PROCEDURE 2
Check Terminal "1" Circuit
1. CHECK POWER SUPPLY FOR STARTER MOTOR “1” TERMINAL
1. Remove the fuel pump fuse.
2. Crank or start the engine (where possible) until the fuel pressure is released.
3. Turn the ignition switch OFF.
4. Disconnect starter motor connector F28.
5. Check voltage between starter motor connector F28 terminal 1
(W/R) and ground using a digital circuit tester.
OK or NG
OK >> GO TO 2.
NG >> Check the following.

40A fusible link (letter m , located in fuse and fusible
link box)

Ignition switch

Starter relay [within the intelligent power distribution module engine room (IPDM E/R)]

Harness for open or short
2. CHECK “1” TERMINAL CONNECTION QUALITY (VOLTAGE DROP TEST)
1. Turn the ignition switch OFF.
2. Connect starter motor connector F28.
3. Check voltage between starter motor connector F28 terminal 1
(W/R) and battery positive terminal using a digital circuit tester.
OK or NG
OK >> Starter motor “1” terminal circuit is OK. Further inspec-
tion is necessary. Refer to SC-13, "
WORK FLOW" .
NG >> Check harness between the battery and the starter
motor “1” terminal for poor continuity. Ignition switch in
START.: Battery voltage
WKIA2108E
Ignition switch in
START.: Less than 1V
WKIA1792E

CHARGING SYSTEM
SC-19
C
D
E
F
G
H
I
J
L
MA
B
SC
Revision: August 20072004 QX56
Trouble Diagnoses with Battery/Starting/Charging System TesterEKS0079G
NOTE:
To ensure a complete and thorough diagnosis, the battery, starter and generator test segments must be done
as a set from start to finish.
1. Turn off all loads on the vehicle electrical system.
2. Perform battery and starting system test with Battery/Starting/
Charging system tester.
3. Press “ENTER” to begin the charging system test.
4. Start engine.
5. Press “ENTER” until “LOADS OFF REV ENGINE 5 SEC” is dis-
played.
6. Raise and hold the engine speed at 1,500 to 2,000 rpm for about
5 seconds, then return the engine to idle.
Once the increase in engine rpm is detected, press “ENTER” to
continue.
NOTE:

If after 30 seconds an increase in engine idle speed is not
detected, “RPM NOT DETECTED” will display.

Some engines may have a higher idle initially after starting,
particularly when the engine is cold. The tester may detect
this without any other action being taken. If this occurs, con-
tinue on with the testing process. The final results will not be affected.
7. The tester now checks the engine at idle and performs the
DIODE/RIPPLE check.
8. When complete, the tester will prompt you to turn on the follow-
ing electrical loads.

Heater fan set to highest speed. Do not run the A/C or wind-
shield defroster.

Headlamp high beam

Rear window defogger
NOTE:
Do not run the windshield wipers or any other cyclical loads.
9. Press “ENTER” to continue.
SEL417X
SEL418X
SEL419X
SEL420X

CHARGING SYSTEM
SC-23
C
D
E
F
G
H
I
J
L
MA
B
SC
Revision: August 20072004 QX56
DIAGNOSTIC PROCEDURE 2
Check Terminal "1" Circuit
1. CHECK “1” TERMINAL CONNECTION
1. Turn the ignition switch OFF.
2. Check to see if “1” terminal is clean and tight.
OK or NG
OK >> GO TO 2.
NG >> Repair “1” terminal connection. Confirm repair by performing complete Battery/Starting/Charging
system test.
2. CHECK GENERATOR “1” TERMINAL CIRCUIT
Check voltage between generator connector E206 terminal 1 (B/R)
and ground using a digital circuit tester.
OK or NG
OK >> GO TO 3.
NG >> Check the following.

140A fusible link (letter a , located in fusible link box)

Harness for open or short between generator and fus-
ible link
3. CHECK “1” TERMINAL CONNECTION QUALITY (VOLTAGE DROP TEST)
Check voltage between generator connector E206 terminal 1 (B/R)
and battery positive terminal using a digital circuit tester.
OK or NG
OK >> Replace the generator. Refer to SC-27, "Removal and
Installation" . Confirm repair by performing complete
Battery/Starting/Charging system test.
NG >> Check harness between the battery and the generator
for poor continuity.
DIAGNOSTIC PROCEDURE 3
Check Terminal "3" Circuit
1. CHECK “3” TERMINAL CONNECTION
1. Turn the ignition switch OFF.
2. Check to see if “3” terminal is clean and tight.
OK or NG
OK >> GO TO 2.
NG >> Repair “3” terminal connection. Confirm repair by performing complete Battery/Starting/Charging
system test. Battery voltage should exist.
W K I A 2111 E
With engine running
at idle and warm.: Less than 0.2V
WKIA2112E

CHARGING SYSTEM
SC-25
C
D
E
F
G
H
I
J
L
MA
B
SC
Revision: August 20072004 QX56
DIAGNOSTIC PROCEDURE 4
Check Terminal "1" Circuit
1. CHECK “1” TERMINAL CONNECTION
1. Turn the ignition switch OFF.
2. Check to see if “1” terminal is clean and tight.
OK or NG
OK >> GO TO 2.
NG >> Repair “1” terminal connection. Confirm repair by performing complete Battery/Starting/Charging
system test.
2. CHECK GENERATOR “1” TERMINAL CIRCUIT
Check voltage between generator connector E206 terminal 1 (B/R)
and ground using a digital circuit tester.
OK or NG
OK >> GO TO 3.
NG >> Check the following.

140A fusible link (letter a , located in fusible link box)

Harness for open or short between generator and fus-
ible link
3. CHECK “1” TERMINAL CONNECTION QUALITY (VOLTAGE DROP TEST)
1. Start the engine.
2. Check voltage between generator connector E206 terminal 1 (B/
R) and battery positive terminal using a digital circuit tester.
OK or NG
OK >> GO TO 4.
NG >> Check harness between the battery and the generator
for poor continuity.
4. CHECK GENERATOR DRIVE BELT TENSION
1. Turn the ignition switch OFF.
2. Check generator drive belt tension. Refer to EM-12, "
DRIVE BELTS" .
OK or NG
OK >> Replace the generator. Refer to SC-27, "Removal and Installation" . Confirm repair by performing
complete battery/starting/charging system test.
NG >> Readjust drive belt tension. Refer to EM-12, "
Tension Adjustment" . Battery voltage should exist.
W K I A 2111 E
With engine running
at idle and warm.: Less than 0.2V
WKIA2112E

SC-26
CHARGING SYSTEM
Revision: August 20072004 QX56
DIAGNOSTIC PROCEDURE 5
Check Terminal "4" Circuit
1. CHECK “4” TERMINAL CONNECTION
1. Turn the ignition switch OFF.
2. Check to see if “4” terminal is clean and tight.
OK or NG
OK >> GO TO 2.
NG >> Repair “4” terminal connection. Confirm repair by performing complete Battery/Starting/Charging
system test.
2. CHECK GENERATOR “4” TERMINAL CIRCUIT
Check voltage between generator connector E205 terminal 4 (Y/B)
and ground using a digital circuit tester.
OK or NG
OK >> GO TO 3.
NG >> Check the following.

10A fuse (No. 30, located in fuse and fusible link box)

Harness for open or short between generator and
fuse
3. CHECK “4” TERMINAL CONNECTION QUALITY (VOLTAGE DROP TEST)
1. Start the engine.
2. Check voltage between generator connector E205 terminal 4 (Y/
B) and battery positive terminal using a digital circuit tester.
OK or NG
OK >> Replace the generator. Refer to SC-27, "Removal and
Installation" . Confirm repair by performing complete
Battery/Starting/Charging system test.
NG >> Check harness between the battery and the generator
for poor continuity. Battery voltage should exist.
WKIA2113E
With engine running
at idle and warm.: Less than 0.2V
WKIA2114E

SE-6
SQUEAK AND RATTLE TROUBLE DIAGNOSES
Revision: August 20072004 QX56
DUPLICATE THE NOISE AND TEST DRIVE
If possible, drive the vehicle with the customer until the noise is duplicated. Note any additional information on
the Diagnostic Worksheet regarding the conditions or location of the noise. This information can be used to
duplicate the same conditions when you confirm the repair.
If the noise can be duplicated easily during the test drive, to help identify the source of the noise, try to dupli-
cate the noise with the vehicle stopped by doing one or all of the following:
1) Close a door.
2) Tap or push/pull around the area where the noise appears to be coming from.
3) Rev the engine.
4) Use a floor jack to recreate vehicle "twist".
5) At idle, apply engine load (electrical load, half-clutch on M/T model, drive position on A/T model).
6) Raise the vehicle on a hoist and hit a tire with a rubber hammer.

Drive the vehicle and attempt to duplicate the conditions the customer states exist when the noise occurs.

If it is difficult to duplicate the noise, drive the vehicle slowly on an undulating or rough road to stress the
vehicle body.
CHECK RELATED SERVICE BULLETINS
After verifying the customer concern or symptom, check ASIST for Technical Service Bulletins (TSBs) related
to that concern or symptom.
If a TSB relates to the symptom, follow the procedure to repair the noise.
LOCATE THE NOISE AND IDENTIFY THE ROOT CAUSE
1. Narrow down the noise to a general area.To help pinpoint the source of the noise, use a listening tool
(Chassis Ear: J-39570, Engine Ear: J-39565 and mechanic's stethoscope).
2. Narrow down the noise to a more specific area and identify the cause of the noise by:

removing the components in the area that you suspect the noise is coming from.
Do not use too much force when removing clips and fasteners, otherwise clips and fasteners can be bro-
ken or lost during the repair, resulting in the creation of new noise.

tapping or pushing/pulling the component that you suspect is causing the noise.
Do not tap or push/pull the component with excessive force, otherwise the noise will be eliminated only
temporarily.

feeling for a vibration with your hand by touching the component(s) that you suspect is (are) causing the
noise.

placing a piece of paper between components that you suspect are causing the noise.

looking for loose components and contact marks.
Refer to SE-7, "
Generic Squeak and Rattle Troubleshooting" .
REPAIR THE CAUSE

If the cause is a loose component, tighten the component securely.

If the cause is insufficient clearance between components:
–separate components by repositioning or loosening and retightening the component, if possible.
–insulate components with a suitable insulator such as urethane pads, foam blocks, felt cloth tape or ure-
thane tape. A NISSAN Squeak and Rattle Kit (J-43980) is available through your authorized Nissan Parts
Department.
CAUTION:
Do not use excessive force as many components are constructed of plastic and may be damaged.
Always check with the Parts Department for the latest parts information.
The following materials are contained in the NISSAN Squeak and Rattle Kit (J-43980). Each item can be
ordered separately as needed.
URETHANE PADS [1.5 mm (0.059 in) thick]
Insulates connectors, harness, etc.
76268-9E005: 100×135 mm (3.94×5.31 in)/76884-71L01: 60×85 mm (2.36×3.35 in)/76884-71L02: 15×25
mm (0.59×0.98 in)
INSULATOR (Foam blocks)
Insulates components from contact. Can be used to fill space behind a panel.
73982-9E000: 45 mm (1.77 in) thick, 50×50 mm (1.97×1.97 in)/73982-50Y00: 10 mm (0.39 in) thick,
50×50 mm (1.97×1.97 in)
INSULATOR (Light foam block)

TF-1
TRANSFER
D DRIVELINE/AXLE
CONTENTS
C
E
F
G
H
I
J
K
L
M
SECTION TF
A
B
TF
Revision: August 20072004 QX56 PREPARATION ........................................................... 4
Special Service Tools ............................................... 4
Commercial Service Tools ........................................ 7
PRECAUTIONS .......................................................... 8
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 8
Precautions .............................................................. 8
Service Notice .......................................................... 9
Wiring Diagrams and Trouble Diagnosis .................. 9
ALL-MODE 4WD SYSTEM ...................................... 10
Cross-sectional View .............................................. 10
Control System ........................................................11
ALL-MODE 4WD TRANSFER BASIC CONTROL
... 12
HYDRAULIC CONTROL CIRCUITS ................... 12
OUTLINE ............................................................. 12
CONTROL SYSTEM DIAGRAM ......................... 13
INDICATIONS OF 4WD WARNING LAMP ......... 13
CAN Communication .............................................. 13
SYSTEM DESCRIPTION .................................... 13
Location of Electrical Parts ..................................... 14
Description of Electrical Parts ................................ 15
TRANSFER MOTOR .......................................... 15
WAIT DETECTION SWITCH .............................. 15
2-4WD SHIFT SOLENOID VALVE ...................... 15
LINE PRESSURE SWITCH ................................ 16
Circuit Diagram for Quick Pinpoint Check .............. 17
Wiring Diagram — T/F — ....................................... 18
ON BOARD DIAGNOSTIC SYSTEM DESCRIP-
TION .......................................................................... 27
Trouble Diagnosis without CONSULT-II ................. 27
DESCRIPTION .................................................... 27
SELF-DIAGNOSTIC PROCEDURE .................... 28
INDICATIONS OF 4WD WARNING LAMP ......... 28CONSULT-II Function (ALL MODE AWD/4WD) ..... 31
Trouble Diagnosis with CONSULT-II ...................... 31
SELF-DIAGNOSIS .............................................. 31
SELF-DIAGNOSTIC ITEMS ................................ 32
DATA MONITOR ................................................. 34
DATA MONITOR ITEMS ..................................... 35
REFERENCE VALUE IN DATA MONITOR MODE
... 38
WORK SUPPORT ............................................... 41
CLUTCH FORCE RELEASE LIMIT ADJUST-
MENT .................................................................. 42
TROUBLE DIAGNOSIS — INTRODUCTION ........... 44
Introduction ............................................................. 44
DESCRIPTION .................................................... 44
DIAGNOSTIC WORKSHEET .............................. 44
Work Flow ............................................................... 46
HOW TO PERFORM TROUBLE DIAGNOSES
FOR QUICK AND ACCURATE REPAIR ............. 46
TROUBLE DIAGNOSIS — BASIC INSPECTION .... 47
Listen to Customer Complaints .............................. 47
Transfer Fluid Check .............................................. 47
Road Test ............................................................... 47
PREPARATION FOR ROAD TEST ..................... 47
1. CHECK BEFORE ENGINE IS STARTED ....... 48
2. CHECK AT IDLE .............................................. 49
3. CRUISE TEST ................................................. 53
TROUBLE DIAGNOSIS — GENERAL DESCRIP-
TION .......................................................................... 55
Transfer Control Unit Terminals and Reference
Value ....................................................................... 55
TRANSFER CONTROL UNIT HARNESS CON-
NECTOR LAYOUT .............................................. 55
TRANSFER CONTROL UNIT INSPECTION
TABLE ................................................................. 55
DTC U1000, U1001 CAN COMMUNICATION LINE ... 59
CAN Communication System Inspection ................ 59
4WD SOLENOID VALVE .......................................... 60
Diagnostic Procedure ............................................. 60
2-4WD SHIFT SOLENOID VALVE AND 4WD SHIFT