brake INFINITI QX56 2007 Factory Service Manual

TROUBLE DIAGNOSIS FOR SYSTEM
TF-81
< SERVICE INFORMATION >
C
E
F
G
H
I
J
K
L
MA
B
TF
N
O
P
Data are reference value and are measured between each terminal and ground.
CAUTION:
When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.
DIAGNOSTIC PROCEDURE
1.CHECK 4WD SHIFT SWITCH SYSTEM
Perform self-diagnosis. Refer to TF-48, "
Self-Diagnosis Procedure".
Is the "4WD MOD SW [P1814]" (with CONSULT-II) or "Flickering pattern: 16 (without CONSULT-II) detected?
YES >> Perform trouble diagnosis for 4WD shift switch. Refer to TF-57, "4WD Shift Switch".
NO >> GO TO 2.
2.CHECK 2-4WD SHIFT SOLENOID 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 “2-4WD SOL” and “2-4WD SOL MON”.
Without CONSULT-II
1. Start engine.
Te r m i n a lWire
colorItem Condition Data (Approx.)
1 GR 2-4WD shift solenoid valve• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: 2WD 0V
4WD shift switch: AUTO, 4H or 4LO Battery voltage
Monitored
itemConditionDisplay
value
2-4WD SOL• Vehicle stopped
• Engine running
• A/T selector lever “N”
position
• Brake pedal de-
pressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO
ON 4WD shift switch: 4H
4WD shift switch: 4LO
4WD shift switch: AUTO
(“Wait” function is operating.)OFF
4WD shift switch: 4H (“Wait”
function is operating.)OFF
2-4WD SOL
MON• Vehicle stopped
• Engine running
• A/T selector lever “N”
position
• Brake pedal de-
pressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO
ON 4WD shift switch: 4H
4WD shift switch: 4LO
4WD shift switch: AUTO
(“Wait” function is operating.)OFF
4WD shift switch: 4H (“Wait”
function is operating.)OFF
SDIA2727E

TF-82
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
2. Check voltage between transfer control unit harness connector
terminal and ground.
OK or NG
OK >> GO TO 7.
NG >> GO TO 3.
3.CHECK 4WD SHIFT SWITCH SIGNAL
1. Turn ignition switch “ON”. (Do not start engine.)
2. Check voltage between transfer control unit harness connector
terminals and ground.
OK or NG
OK >> GO TO 4.
NG >> Check 4WD shift switch. Refer to TF-57, "
4WD Shift Switch".
4.CHECK HARNESS BETWEEN 4WD SHIFT SWITCH AND TRANSFER TERMINAL CORD ASSEMBLY
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect 4WD shift switch harness connector and transfer terminal cord assembly harness connector.
3. Check continuity between 4WD shift switch harness connector
M141 terminal 4 and transfer terminal cord assembly harness
connector F56 terminal 5.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
5.CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND TRANSFER TERMINAL CORD AS-
SEMBLY
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and transfer terminal cord assembly harness connec-
tor.
Connector Terminal ConditionVoltage
(Approx.)
E142 1 -
Ground• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 2WD 0V
4WD shift switch: AU-
TO, 4H or 4LOBattery
voltage
SDIA2728E
Connector Terminal ConditionVoltage (Ap-
prox.)
M141 4 - ground4WD shift switch: AUTO, 4H or 4LO Battery voltage
4WD shift switch: 2WD 0V
SDIA2729E
Continuity should exist.
SDIA2731E

TF-84
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
Transfer Motor
INFOID:0000000003532543
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Data are reference value.
TRANSFER CONTROL UNIT TERMINALS AND REFERENCE VALUE
Data are reference value and are measured between each terminal and ground.
Monitored item Content Condition Display value
MOTOR RELAY [ON/
OFF]Condition of transfer motor
relay• Accelerator pedal de-
pressed
• Vehicle stopped
• Engine running
• Brake pedal depressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO
or 4LO (A/T selector lever
“P” or “N” position)OFF
("ON" for approx. 2
sec. after shifting to
“P” and “N”.)
4WD shift switch: AUTO
or 4LO (Except for A/T se-
lector lever “P” or “N” posi-
tion)ON
4WD shift switch: 4H (A/T
selector lever “P” position)OFF
("ON" for approx. 2
sec. after shifting to
“P”.)
4WD shift switch: 4H (Ex-
cept for A/T selector lever
“P” position)ON
MOTOR RELAY MON
[ON/OFF]Check signal for transfer
control unit signal output• Accelerator pedal de-
pressed
• Vehicle stopped
• Engine running
• Brake pedal depressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO
or 4LO (A/T selector lever
“P” or “N” position)OFF
("ON" for approx. 2
sec. after shifting to
“P” and “N”.)
4WD shift switch: AUTO
or 4LO (Except for A/T se-
lector lever “P” or “N” posi-
tion)ON
4WD shift switch: 4H (A/T
selector lever “P” position)OFF
("ON" for approx. 2
sec. after shifting to
“P”.)
4WD shift switch: 4H (Ex-
cept for A/T selector lever
“P” position)ON
Te r m i n a lWire
colorItem Condition Data (Approx.)
14 LG Transfer motor relay• Accelerator ped-
al depressed
• Vehicle stopped
• Engine running
• Brake pedal de-
pressed4WD shift switch: 2WD Battery voltage
4WD shift switch: AUTO or 4LO (A/T selec-
tor lever “P” or “N” position)Battery voltage
(0V for approx.
2 sec. after
shifting to “P”
and “N”.)
4WD shift switch: AUTO or 4LO (Except for
A/T selector lever “P” or “N” position)0V
4WD shift switch: 4H (A/T selector lever
“P” position)Battery voltage
(0V for approx.
2 sec. after
shifting to “P”.)
4WD shift switch: 4H (Except for A/T selec-
tor lever “P” position)0V

TROUBLE DIAGNOSIS FOR SYSTEM
TF-85
< SERVICE INFORMATION >
C
E
F
G
H
I
J
K
L
MA
B
TF
N
O
P
CAUTION:
When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.
DIAGNOSTIC PROCEDURE
1.CHECK TRANSFER MOTOR RELAY 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 “MOTOR RELAY” and “MOTOR RELAY
MON”.
41 R Transfer motor relay monitor• Accelerator ped-
al depressed
• Vehicle stopped
• Engine running
• Brake pedal de-
pressed4WD shift switch: 2WD 0V
4WD shift switch: AUTO or 4LO (A/T selec-
tor lever “P” or “N” position)0V
(Battery volt-
age for approx.
2 sec. after
shifting to “P”
and “N”.)
4WD shift switch: AUTO or 4LO (Except for
A/T selector lever “P” or “N” position)Battery voltage
4WD shift switch: 4H (A/T selector lever
“P” position)0V
(Battery volt-
age for approx.
2 sec. after
shifting to “P”.)
4WD shift switch: 4H (Except for A/T selec-
tor lever “P” position)Battery voltage Te r m i n a lWire
colorItem Condition Data (Approx.)
Monitored
itemConditionDisplay value
(Approx.)
MOTOR
RELAY• Accelerator ped-
al depressed
• Vehicle stopped
• Engine running
• Brake pedal de-
pressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO or
4LO (A/T selector lever “P” or
“N” position)OFF
("ON" for ap-
prox. 2 sec. af-
ter shifting to
“P” and “N”.)
4WD shift switch: AUTO or
4LO (Except for A/T selector
lever “P” or “N” position)ON
4WD shift switch: 4H (A/T se-
lector lever “P” position)OFF
("ON" for ap-
prox. 2 sec. af-
ter shifting to
“P”.)
4WD shift switch: 4H (Except
for A/T selector lever “P” posi-
tion)ON
SDIA2734E

TF-86
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
Without CONSULT-II
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminal and ground.
MOTOR
RELAY
MON• Accelerator ped-
al depressed
• Vehicle stopped
• Engine running
• Brake pedal de-
pressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO or
4LO (A/T selector lever “P” or
“N” position)OFF
("ON" for ap-
prox. 2 sec. af-
ter shifting to
“P” and “N”.)
4WD shift switch: AUTO or
4LO (Except for A/T selector
lever “P” or “N” position)ON
4WD shift switch: 4H (A/T se-
lector lever “P” position)OFF
("ON" for ap-
prox. 2 sec. af-
ter shifting to
“P”.)
4WD shift switch: 4H (Except
for A/T selector lever “P” posi-
tion)ON Monitored
itemConditionDisplay value
(Approx.)
Connector Terminal Condition Voltage (Approx.)
E142 14 -
Ground• Accelera-
tor pedal
depressed
• Vehicle
stopped
•Engine
running
•Brake
pedal de-
pressed4WD shift switch:
2WDBattery voltage
4WD shift switch:
AUTO or 4LO (A/T
selector lever “P” or
“N” position)Battery voltage
(0V for approx. 2
sec. after shifting
to “P” and “N”.)
4WD shift switch:
AUTO or 4LO (Ex-
cept for A/T selector
lever “P” or “N” posi-
tion)0V
4WD shift switch: 4H
(A/T selector lever
“P” position)Battery voltage
(0V for approx. 2
sec. after shifting
to “P”.)
4WD shift switch: 4H
(Except for A/T se-
lector lever “P” posi-
tion)0V
SDIA2735E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-87
< SERVICE INFORMATION >
C
E
F
G
H
I
J
K
L
MA
B
TF
N
O
P
OK or NG
OK >> GO TO 7.
NG >> GO TO 2.
2.CHECK TRANSFER MOTOR RELAY POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Connect transfer control unit harness connector.
3. Disconnect transfer motor relay.
4. Check voltage between transfer motor relay harness connector
terminals and ground.
5. Turn ignition switch “ON”. (Do not start engine.)
6. Check voltage between transfer motor relay harness connector
terminals and ground.
OK or NG
OK >> GO TO 3.
NG >> Check the following. If any items are damaged, repair
or replace damaged parts.
• 20A fuse No. 58 located in the fuse and relay box. Refer to PG-3
.
• 10A fuse No. 26 located in the fuse and fusible link box. Refer to PG-3
.
• Harness for short or open between battery and transfer motor relay harness connector E154 ter-
minal 5.
E143 41 -
Ground• Accelera-
tor pedal
depressed
• Vehicle
stopped
•Engine
running
•Brake
pedal de-
pressed4WD shift switch:
2WD0V
4WD shift switch:
AUTO or 4LO (A/T
selector lever “P” or
“N” position)0V
(Battery voltage
for approx. 2 sec.
after shifting to “P”
and “N”.)
4WD shift switch:
AUTO or 4LO (Ex-
cept for A/T selector
lever “P” or “N” posi-
tion)Battery voltage
4WD shift switch: 4H
(A/T selector lever
“P” position)0V
(Battery voltage
for approx. 2 sec.
after shifting to
“P”.)
4WD shift switch: 4H
(Except for A/T se-
lector lever “P” posi-
tion)Battery voltage Connector Terminal Condition Voltage (Approx.)
Connector Terminal Voltage (Approx.)
E153 2 - Ground 0V
E154 5 - Ground Battery voltage
WDIA0169E
Connector Terminal Voltage (Approx.)
E153 2 - Ground
Battery voltage
E154 5 - Ground
WDIA0170E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-99
< SERVICE INFORMATION >
C
E
F
G
H
I
J
K
L
MA
B
TF
N
O
P
CAN Communication LineINFOID:0000000003532551
DIAGNOSTIC PROCEDURE
1.CHECK CAN COMMUNICATION CIRCUIT
With CONSULT-II
1. Turn ignition switch “ON” and start engine.
2. Select “SELF-DIAG RESULTS” mode for “ALL MODE AWD/4WD” within CONSULT-II.
3. Perform the self-diagnosis.
Is the
“CAN COMM CIRCUIT [U1000]” displayed?
YES >> Print CONSULT-II screen and go to LAN-40.
NO >> Inspection End.
ATP SwitchINFOID:0000000003532552
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Data are reference value.
TRANSFER CONTROL UNIT TERMINALS AND REFERENCE VALUE
Data are reference value and are measured between each terminal and ground.
CAUTION:
When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.
DIAGNOSTIC PROCEDURE
1.CHECK ATP SWITCH SIGNAL
With CONSULT-II
1. Start engine.
2. Select “DATA MONITOR” mode for “ALL MODE AWD/4WD” with CONSULT-II.
SDIA1850E
Monitored item [Unit] Content Condition Display value
ATP SWITCH [ON/OFF] Condition of ATP switch• Vehicle stopped
• Engine running
• A/T selector lever “N"
• Brake pedal depressed4WD shift switch
: 4H to 4LO or 4LO to 4H
(While actuator motor is
operating.) ON
Except the above OFF
Te r m i n a lWire
colorItem Condition Data (Approx.)
40 L ATP switch• Vehicle stopped
• Engine running
• A/T selector le-
ver “N"
• Brake pedal de-
pressed4WD shift switch: 4H to 4LO or 4LO to 4H
(While actuator motor is operating.)0V
Except the above Battery voltage

TF-100
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
3. Read out the value of “ATP SWITCH”.
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 ATP SWITCH
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and the ATP switch harness connector.
3. Check continuity between transfer control unit harness connec-
tor E143 terminal 40 and ATP switch harness connector F55 ter-
minal 8.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3.CHECK GROUND CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect ATP switch harness connector.
3. Check continuity between ATP switch harness connector F55
terminal 9 and ground.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
Condition Display value
• Vehicle stopped
• Engine running
• A/T selector lever
“N"
• Brake pedal de-
pressed4WD shift switch
: 4H to 4LO or 4LO to 4H
(While actuator motor is operating.) ON
Except the above OFF
SDIA2391E
Connector Terminal ConditionVoltage
(Approx.)
E14340 -
Ground• Vehicle stopped
• Engine running
• A/T selector lever
“N"
• Brake pedal de-
pressed4WD shift switch: 4H
to 4LO or 4LO to 4H
(While actuator motor
is operating.)0V
Except the aboveBattery
voltage
SDIA2755E
Continuity should exist.
SDIA2756E
Continuity should exist.
SDIA2394E

WT-4
< SERVICE INFORMATION >
NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTING
NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTING
NVH Troubleshooting ChartINFOID:0000000003532688
Use the chart below to help you find the cause of the symptom. If necessary, repair or replace these parts.
×: ApplicableReference page
WT-5WT-6WT-28WT-7—
—
WT-28
FFD-6, "
NVH Troubleshooting Chart
" (FFD),
RFD-7, "
NVH Troubleshooting Chart
" (RFD)
FA X - 4 , "
NVH Troubleshooting Chart
" (FAX),
FSU-4, "
NVH Troubleshooting Chart
" (FSU)
RAX-4, "
NVH Troubleshooting Chart
" (RAX),
RSU-4, "
NVH Troubleshooting Chart
" (RSU)
Refer to TIRES in this chart.
Refer to ROAD WHEEL in this chart.
BR-4, "
NVH Troubleshooting Chart
"
PS-5, "
NVH Troubleshooting Chart
"
Possible cause and SUSPECTED PARTS
Out-of-round
Imbalance
Incorrect tire pressure
Uneven tire wear
Deformation or damage
Non-uniformity
Incorrect tire size
DIFFERENTIAL
FRONT AXLE AND FRONT SUSPENSION
REAR AXLE AND REAR SUSPENSION
TIRES
ROAD WHEEL
BRAKE
STEERING
SymptomTIRESNoise× ××××× × × × × ××
Shake× ×××× × × × × ××
Vibration××××××
Shimmy× ×××××× × × × ××
Shudder× ×××× × × × × ××
Poor quality ride or
handling× ×××× × × × ×
ROAD
WHEELNoise×× × ××× ×××
Shake×× × ×× ×××
Shimmy, shudder×× × ×× ×××
Poor quality ride or
handling×× × ×× ×