2007 INFINITI QX56 brake

TROUBLE DIAGNOSIS FOR SYSTEM
TF-77
< 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 CLUTCH PRESSURE SIGNAL
With CONSULT-II1. Start engine.
2. Select “DATA MONITOR” mode for “ALL MODE AWD/4WD” with CONSULT-II.
3. Read out the value of “DUTY SOLENOID”.
Without CONSULT-II
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminal and ground.
OK or NG
OK >> GO TO 7.
NG >> GO TO 2.
Te r m i n a lWire
colorItem Condition Data (Approx.)
10 L/W Transfer dropping resistor• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: AUTO 4 - 14V
4WD shift switch: 2WD, 4H or 4LO Less than 1V
19 LClutch pressure solenoid
valve• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: AUTO 1.5 - 3V
4WD shift switch: 2WD, 4H or 4LO Less than 1V
Condition Display value
• Vehicle stopped
• Engine running
• A/T selector lever “N” position
• Brake pedal depressed4WD shift switch: 2WD 4%
4WD shift switch: AUTO 96 - 4%
4WD shift switch: 4H or
4LO4%
SDIA2718E
Connector Terminal ConditionVoltage
(Approx.)
E142 10 -
Ground• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch:
AUTO4 - 14V
4WD shift switch:
2WD, 4H or 4LOLess than
1V
19 -
Ground• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch:
AUTO1.5 - 3V
4WD shift switch:
2WD, 4H or 4LOLess than
1V
SDIA2719E

TF-80
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
3. Check resistance between transfer terminal cord assembly ter-
minals 6 and 19.
4. If NG, replace clutch pressure solenoid. Refer to TF-22, "
Loca-
tion of Electrical Parts" .
Transfer Dropping Resistor
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer dropping resistor harness connector.
3. Check resistance between transfer dropping resistor terminals 1
and 2.
4. If NG, replace transfer dropping resistor. Refer to TF-22, "
Loca-
tion of Electrical Parts".
2-4WD SolenoidINFOID:0000000003532542
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Data are reference value.
TRANSFER CONTROL UNIT TERMINALS AND REFERENCE VALUE
6 - 19 : Approx. 3.0 - 3.4 Ω
WDIA0225E
1 - 2 : Approx. 11.2 - 12.8 Ω
SDIA2725E
Monitored item Content Condition Display value
2-4WD SOL [ON/OFF]Condition of 2-4WD shift
solenoid valve• Vehicle stopped
• Engine running
• A/T selector lever “N”
position
• Brake pedal depressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO
ON 4WD shift switch: 4H
4WD shift switch: 4LO
4WD shift switch: AUTO
(“Wait” function is operat-
ing.)OFF
4WD shift switch: 4H
(“Wait” function is operat-
ing.)OFF
2-4WD SOL MON [ON/
OFF]Check signal for transfer
control unit signal output• Vehicle stopped
• Engine running
• A/T selector lever “N”
position
• Brake pedal depressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO
ON 4WD shift switch: 4H
4WD shift switch: 4LO
4WD shift switch: AUTO
(“Wait” function is operat-
ing.)OFF
4WD shift switch: 4H
(“Wait” function is operat-
ing.)OFF

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