2007 INFINITI QX56 brake

TROUBLE DIAGNOSIS
TF-39
< SERVICE INFORMATION >
C
E
F
G
H
I
J
K
L
MA
B
TF
N
O
P Specifications Between Transfer Control Unit Terminals
TRANSFER CONTROL UNIT TERMINAL CONNECTOR LAYOUT
NOTE:
Data are reference value and are measured between each terminal and ground.
SHIFT AC MON2 [ON/
OFF]Check signal for transfer
control unit signal output• Vehicle stopped
• Engine running
• A/T selector lever “N” posi-
tion
• Brake pedal depressed4WD shift switch: 4LO to
4H (“Wait” function is op-
erating.)ON
Except the above OFF
T/F F SPEED [km/h] or
[mph]Displayed, but do not use.
A/T R SPEED [km/h] or
[mph]Condition of vehicle
speed sensor A/T (Revo-
lution sensor)During drivingApproximately
matches the out-
put shaft speed.
AT GEAR POSI [1/2/3/4/
5]Condition of A/T selector
lever positionDisplays actual A/T gear position. 1/2/3/4/5 Monitored item [Unit] Content Condition Display value
WDIA0378E
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 lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 2WD 0V
4WD shift switch: AUTO, 4H or 4LO Battery voltage
2 B/W4WD shift indicator lamp
(2WD indicator lamp)2WD indicator lamp: OFF Battery voltage
2WD indicator lamp: ON 0V
3 B Ground Always 0V
4 Y/L Transfer shift high relay• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 4H to 4LO (“Wait” func-
tion is operating.)Battery voltage
Except the above 0V
5 W/B 4WD warning lamp4WD warning lamp: ON 0V
4WD warning lamp: OFF Battery voltage
6 B Ground Always 0V
7 L CAN-H — —
8 P CAN-L — —
9G/W4WD shift switch
(2WD)Ignition switch: ON4WD shift switch: 2WD Battery voltage
4WD shift switch: AUTO, 4H or 4LO 0V

TF-40
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
10 L/W Transfer dropping resistor• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: AUTO 4 - 14V
4WD shift switch: 2WD, 4H or 4LO Less than 1V
11 L4WD shift indicator lamp
(Lock indicator lamp)Lock indicator lamp of 4WD shift indicator lamp: OFF Battery voltage
Lock indicator lamp of 4WD shift indicator lamp: ON 0V
12 W/G 4LO indicator lamp4LO indicator lamp: OFF Battery voltage
4LO indicator lamp: ON 0V
13 G/B Transfer shift low relay• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 4LO to 4H (“Wait” func-
tion is operating.)Battery voltage
Except the above 0V
14 LG Transfer motor relay• Accelerator pedal
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
15 L/B ATP warning lampATP indicator lamp: ON 0V
ATP indicatorlamp: OFF Battery voltage
16 Y/R Power supplyIgnition switch: ON Battery voltage
Ignition switch: OFF 0V
18 O4WD shift switch
(4H)Ignition switch: ON4WD shift switch: 4H Battery voltage
4WD shift switch: 2WD, AUTO or 4LO 0V
19 LClutch pressure solenoid
valve• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: AUTO 1.5 - 3V
4WD shift switch: 2WD, 4H or 4LO Less than 1V
21 BR4WD shift indicator lamp
(AUTO indicator lamp)• AUTO indicator lamp of 4WD shift indicator lamp: OFF Battery voltage
AUTO indicator lamp of 4WD shift indicator lamp: ON 0V
22 Y/R Power supplyIgnition switch: ON Battery voltage
Ignition switch: OFF 0V
23 R4WD shift switch
(4LO)Ignition switch: ON4WD shift switch: 4LO Battery voltage
4WD shift switch: 2WD, AUTO or 4H 0V
24 LG/R4WD shift switch
(AUTO)Ignition switch: ON4WD shift switch: AUTO Battery voltage
4WD shift switch: 2WD, 4H or 4LO 0V Te r m i n a lWire
colorItem Condition Data (Approx.)

TROUBLE DIAGNOSIS
TF-41
< SERVICE INFORMATION >
C
E
F
G
H
I
J
K
L
MA
B
TF
N
O
P
25 V Neutral-4LO switch• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 2WD, AUTO or 4H Battery voltage
4WD shift switch: 4H to 4LO (While actua-
tor motor is operating.)Battery voltage
→ 0V
4WD shift switch: 4LO to 4H (While actua-
tor motor is operating.)0V → Battery
voltage
4WD shift switch: 4LO 0V
27 W/LActuator position switch 2
(High)• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 4H, AUTO or 2WD 0V
4WD shift switch: 4LO Battery voltage
28 B/G Sensor ground Always 0V
29 L/W Ignition switch monitorIgnition switch: ON Battery voltage
Ignition switch: OFF 0V
30 SB Shut off relayIgnition switch: ON 0V
Ignition switch: OFF Battery voltage
31 GTransfer fluid temperature
sensorIgnition switch: ONTransfer fluid temperature approx. 20°C
(68°F)1.1V
Transfer fluid temperature approx. 80°C
(176°F)0.3V
33 R/LTransfer shift high relay
monitor• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 4H to 4LO (“Wait” func-
tion is operating.)Battery voltage
Except the above 0V
34 BR Clutch pressure switch• Vehicle stopped
• Engine running
• A/T selector lever
“D” position4WD shift switch: AUTO or 4H (“Wait” func-
tion is not operating.)0V
• Vehicle stopped
• Engine running4WD shift switch: 2WD (“Wait” function is
not operating.)Battery voltage
35BR/
WLine pressure switch• Ignition switch: ON
• A/T selector lever “D” position
• 4WD shift switch: AUTO0V
• After the vehicle
has been left at
room temperature
for 5 minutes and
more with ignition
switch in “OFF” po-
sition.• Ignition switch: ON
• A/T selector lever: “P” or "N" position
• 4WD shift switch: other than AUTOBattery voltage
40 L ATP switch• 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 above Battery voltage Te r m i n a lWire
colorItem Condition Data (Approx.)

TF-42
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
CAUTION:
When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.
CONSULT-II Function (ALL MODE AWD/4WD)INFOID:0000000003532527
FUNCTION
CONSULT-II can display each diagnostic item using the diagnostic test modes shown following.
41 RTransfer motor relay moni-
tor• Accelerator pedal
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
42 P/GTransfer shift low relay
monitor• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 4LO to 4H (“Wait” func-
tion is operating.)Battery voltage
Except the above 0V
43 G/Y Wait detection switch• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 2WD, AUTO or 4H Battery voltage
4WD shift switch: 4H to 4LO (While actua-
tor motor is operating.)Battery voltage
→ 0V
4WD shift switch: 4LO to 4H (While actua-
tor motor is operating.)0V → Battery
voltage
4WD shift switch: 4LO 0V
44 LG/BActuator position switch 1
(Low)• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 4LO 0V
4WD shift switch: 2WD, AUTO or 4H Battery voltage
45 B Ground Always 0V
47 WPower supply
(Memory back-up)Ignition switch: ON Battery voltage
Ignition switch: OFF Battery voltage Te r m i n a lWire
colorItem Condition Data (Approx.)
ALL MODE AWD/4WD diag-
nostic modeDescription
SELF-DIAG RESULTS Displays transfer control unit self-diagnosis results.
DATA MONITOR Displays transfer control unit input/output data in real time.
WORK SUPPORTSupports inspections and adjustments. Commands are transmitted to the transfer control unit for set-
ting the status suitable for required operation, input/output signals are received from the transfer control
unit and received data is displayed.
CAN DIAG SUPPORT MNTR The results of transmit/receive diagnosis of CAN communication can be read.
ECU PART NUMBER Transfer control unit part number can be read.

TF-54
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
2.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-51, "
Power Supply Circuit for Transfer Control Unit"
.
OK or NG
OK >> GO TO 3.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
3.CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
OK or NG
OK >> Inspection End.
NG >> Perform self-diagnosis with TCM again. Refer to TF-48, "
Self-Diagnosis Procedure".
Vehicle Speed Sensor (ABS)INFOID:0000000003532532
DIAGNOSTIC PROCEDURE
1.CHECK DTC WITH ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
Perform self-diagnosis with ABS actuator and electric unit (control unit). Refer to BRC-26, "
CONSULT-II Func-
tion (ABS)".
Is any malfunction detected by self-diagnosis?
YES >> Check the malfunctioning system.
NO >> GO TO 2.
2.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-35, "
Transfer Control Unit Input/Output Signal Ref-
erence Value".
OK or NG
OK >> GO TO 3.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
3.CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
OK or NG
OK >> Inspection End.
NG >> Perform self-diagnosis with ABS actuator and electric unit (control unit) again. Refer to BRC-26,
"CONSULT-II Function (ABS)".
Neutral-4LO SwitchINFOID:0000000003532533
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Data are reference value.
TRANSFER CONTROL UNIT TERMINALS AND REFERENCE VALUE
Monitored item Content Condition Display value
N POSI SW TF [ON/
OFF]Condition of neutral-4LO
switch• 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 mo-
tor is operating.)OFF → ON
4WD shift switch: 4LO to
4H (While actuator motor
is operating.)ON → OFF
4WD shift switch: 4LO ON

TROUBLE DIAGNOSIS FOR SYSTEM
TF-55
< 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 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.
Te r m i n a lWire
colorItem Condition Data (Approx.)
25 V Neutral-4LO switch• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: 2WD, AUTO or 4H Battery voltage
4WD shift switch: 4H to 4LO (While actua-
tor motor is operating.)Battery voltage
→ 0V
4WD shift switch: 4LO to 4H (While actua-
tor motor is operating.)0V → Battery
voltage
4WD shift switch: 4LO 0V
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 mo-
tor 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 col-
or)ConditionVoltage
(Approx.)
E143 25 -
Ground• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD 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

TROUBLE DIAGNOSIS FOR SYSTEM
TF-57
< SERVICE INFORMATION >
C
E
F
G
H
I
J
K
L
MA
B
TF
N
O
P
2. Disconnect neutral-4LO switch harness connector.
3. Remove neutral-4LO switch. Refer to TF-22, "
Location of Electrical Parts".
4. Push and release neutral-4LO switch and check continuity
between neutral-4LO switch terminals 12 and 13.
5. If NG, replace the neutral-4LO switch. Refer to TF-22, "
Location
of Electrical Parts".
4WD Shift SwitchINFOID:0000000003532534
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 4WD SHIFT SWITCH SIGNAL
With CONSULT-II
1. Turn ignition switch “ON”. (Do not start engine.)
Terminal Condition Continuity
12 - 13Push neutral-4LO switch Yes
Release neutral-4LO switch No
SDIA2696E
Monitored item [Unit] Content Condition Display value
2WD SWITCH [ON/OFF]Input condition from 4WD
shift switch4WD shift switch: 2WD ON
4WD shift switch: AUTO, 4H or 4LO OFF
AUTO SWITCH [ON/
OFF]Input condition from 4WD
shift switch4WD shift switch: AUTO ON
4WD shift switch: 2WD, 4H or 4LO OFF
LOCK SWITCH [ON/
OFF]Input condition from 4WD
shift switch4WD shift switch: 4H ON
4WD shift switch: 2WD, AUTO or 4LO OFF
4L SWITCH [ON/OFF]Input condition from 4WD
shift switch4WD shift switch: 4LO ON
4WD shift switch: 2WD, AUTO or 4H OFF
4WD MODE [AUTO/
LOCK/2WD/4L]Control status of 4WD
(Output condition of 4WD
shift indicator lamp and
4LO indicator lamp)• Vehicle stopped
• Engine running
• A/T selector lever “N”
position
• Brake pedal depressed4WD shift switch: 2WD 2WD
4WD shift switch: AUTO AUTO
4WD shift switch: 4H LOCK
4WD shift switch: 4LO 4L
Te r m i n a lWire
colorItem Condition Data (Approx.)
9G/W4WD shift switch
(2WD)Ignition switch: ON4WD shift switch: 2WD Battery voltage
4WD shift switch: AUTO, 4H or 4LO 0V
18 O4WD shift switch
(4H)Ignition switch: ON4WD shift switch: 4H Battery voltage
4WD shift switch: 2WD, AUTO or 4LO 0V
23 R4WD shift switch
(4LO)Ignition switch: ON4WD shift switch: 4LO Battery voltage
4WD shift switch: 2WD, AUTO or 4H 0V
24 LG/R4WD shift switch
(AUTO)Ignition switch: ON4WD shift switch: AUTO Battery voltage
4WD shift switch: 2WD, 4H or 4LO 0V

TROUBLE DIAGNOSIS FOR SYSTEM
TF-61
< SERVICE INFORMATION >
C
E
F
G
H
I
J
K
L
MA
B
TF
N
O
P
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 WAIT DETECTION 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 “WAIT DETCT SW”.
Without CONSULT-II
1. Start engine.
Monitored item Content Condition Display value
WAIT DETCT SW [ON/
OFF]Condition of wait detection
switch• 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 mo-
tor is operating.)OFF → ON
4WD shift switch: 4LO to
4H (While actuator motor
is operating.)ON → OFF
4WD shift switch: 4LO ON
Te r m i n a lWire
colorItem Condition Data (Approx.)
43 G/Y Wait detection switch• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: 2WD, AUTO or 4H Battery voltage
4WD shift switch: 4H to 4LO (While actua-
tor motor is operating.)Battery voltage
→ 0V
4WD shift switch: 4LO to 4H (While actua-
tor motor is operating.)0V → Battery
voltage
4WD shift switch: 4LO 0V
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 operat-
ing.)OFF → ON
4WD shift switch: 4LO to 4H
(While actuator motor is operat-
ing.)ON → OFF
4WD shift switch: 4LO ON
PDIA0221E