2006 INFINITI QX56 engine

TF-36
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
LOCK SWITCH [ON/
OFF]Input condition from
4WD shift switch 4WD shift switch: 4H
ON
4WD shift switch: 2WD, AUTO or 4LO OFF
4L SWITCH [ON/OFF] Input condition from
4WD shift switch 4WD shift switch: 4LO
ON
4WD shift switch: 2WD, AUTO or 4H OFF
N POSI SW TF [ON/
OFF] Condition of neutral-4LO
switch

Vehicle stopped

Engine running

A/T selector lever
“N ” posi-
tion

Brake pedal depressed 4WD shift switch: 2WD,
AUTO or 4H
OFF
4WD shift switch: 4H to
4LO (While actuator
motor is operating.) OFF
→ ON
4WD shift switch: 4LO to
4H (While actuator motor
is operating.) ON
→ OFF
4WD shift switch: 4LO ON
ATP SWITCH [ON/OFF] Condition of ATP switch

Vehicle stopped

Engine running

A/T selector lever “N ”

Brake pedal depressed 4WD shift switch
: 4H to 4LO or 4LO to 4H
(While actuator motor is
operating.)
ON
Except the above OFF
WAIT DETCT SW [ON/
OFF] Condition of wait detec-
tion switch

Vehicle stopped

Engine running

A/T selector lever
“N ” posi-
tion

Brake pedal depressed 4WD shift switch: 2WD,
AUTO or 4H
OFF
4WD shift switch: 4H to
4LO (While actuator
motor is operating.) OFF
→ ON
4WD shift switch: 4LO to
4H (While actuator motor
is operating.) ON
→ OFF
4WD shift switch: 4LO ON
LINE PRES SW [ON/
OFF] Condition of line pres-
sure switch

A/T selector lever
“D ” position

4WD shift switch: 2WD, AUTO or 4H ON

Except the above

The vehicle has been left
at room temperature for 5
minutes and more with
ignition switch in “
OFF”
position.
Ignition switch: ON

A/T selector lever: “P ”
or "N" position

4WD shift switch: other
than AUTO OFF
CL PRES SW [ON /
OFF] Condition of clutch pres-
sure switch

Vehicle stopped

Engine running

A/T selector lever
“D ” position

4WD shift switch: AUTO or 4H (“ Wait” function is not
operating.) ON

Vehicle stopped

Engine running

4WD shift switch: 2WD (
“Wait ” function is not operat-
ing.) OFF
N POSI SW AT [ON/
OFF] Input condition from A/T
PNP switch

Vehicle stopped

Engine running

Brake pedal depressed A/T selector lever posi-
tion: N
ON
Except the above OFF
R POSI SW AT [ON/
OFF] Input condition from A/T
PNP switch

Vehicle stopped

Engine running

Brake pedal depressed A/T selector lever posi-
tion: R
ON
Except the above OFF
Monitored item [Unit]
Content ConditionDisplay value

TROUBLE DIAGNOSISTF-37
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Revision: November 2009 2006 QX56
P POSI SW AT [ON/
OFF]Input condition from A/T
PNP switch
Vehicle stopped

Engine running

Brake pedal depressed A/T selector lever posi-
tion: P
ON
Except the above OFF
ABS OPER SW [ON/
OFF] Condition of ABS operat-
ing ABS is operating.
ON
ABS is not operating. OFF
VDC OPER SW [ON/
OFF] Condition of VDC operat-
ing VDC is operating.
ON
VDC is not operating. OFF
TCS OPER SW [ON/
OFF] Condition of TCS operat-
ing TCS is operating.
ON
TCS is not operating. OFF
THROTTLE POSI [0.0/8] Condition of throttle
opening When depressing accelerator pedal
(Value rises gradually in response to throttle position.)
0.0/8 - 8.0/8
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” posi-
tion

Brake pedal depressed 4WD shift switch: 2WD
2WD
4WD shift switch: AUTO AUTO
4WD shift switch: 4H LOCK
4WD shift switch: 4LO 4L
VHCL/S COMP [km/h] or
[mph] Vehicle speed Vehicle stopped
0 km/h (0 MPH)
Vehicle running
CAUTION:
Check air pressure of tire under standard condition. Approximately
equal to the indi-
cation on speed-
ometer (Inside of
±
10%)
COMP CL TORQ [kgm] Condition of control
torque

Vehicle stopped

Engine running

A/T selector lever “
N” posi-
tion

Brake pedal depressed 4WD shift switch: 2WD 0 kg-m
4WD shift switch: AUTO
39 - 1,353 N
·m
(4 - 138 kg-m, 29 - 998 ft-lb)
4WD shift switch: 4H or
4LO 1,353 N
·m
(138 kg-m, 998 ft- lb)
DUTY SOLENOID [%] Condition of clutch pres-
sure solenoid

Vehicle stopped

Engine running

A/T selector lever “
N” posi-
tion

Brake pedal depressed 4WD shift switch: 2WD
4%
4WD shift switch: AUTO 96 - 4%
4WD shift switch: 4H or
4LO 4%
2-4WD SOL [ON/OFF] Condition of 2-4WD shift
solenoid valve

Vehicle stopped

Engine running

A/T selector lever “
N” posi-
tion

Brake pedal depressed 4WD 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
Monitored item [Unit]
Content ConditionDisplay value

TF-38
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
2-4WD SOL MON [ON/
OFF]Check signal for transfer
control unit signal output

Vehicle stopped

Engine running

A/T selector lever
“N ” posi-
tion

Brake pedal depressed 4WD 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
MOTOR RELAY [ON/
OFF] Condition of transfer
motor relay

Accelerator pedal
depressed

Vehicle stopped

Engine running

Brake pedal depressed 4WD 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
selector lever “P ” or “ N”
position) ON
4WD shift switch: 4H (A/T
selector lever “P ” posi-
tion) OFF
("ON" for approx. 2 sec. after shifting to “P”.)
4WD shift switch: 4H
(Except for A/T selector
lever “P ” position) ON
MOTOR RELAY MON
[ON/OFF] Check signal for transfer
control unit signal output

Accelerator pedal
depressed

Vehicle stopped

Engine running

Brake pedal depressed 4WD 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
selector lever “P ” or “ N”
position) ON
4WD shift switch: 4H (A/T
selector lever “P ” posi-
tion) OFF
("ON" for approx. 2
sec. after shifting to “P”.)
4WD shift switch: 4H
(Except for A/T selector
lever “P ” position) ON
4WD FAIL LAMP [ON/
OFF] Condition of 4WD warn-
ing lamp 4WD warning lamp: ON
ON
4WD warning lamp: OFF OFF
2WD IND [ON/OFF] Condition of 4WD shift
indicator lamp (2WD
indicator lamp) 2WD indicator lamp of 4WD shift indicator lamp: OFF
OFF
2WD indicator lamp of 4WD shift indicator lamp: ON ON
AUTO IND [ON/OFF] Condition of 4WD shift
indicator lamp (AUTO
indicator lamp) AUTO indicator lamp of 4WD shift indicator lamp: OFF
OFF
AUTO indicator lamp of 4WD shift indicator lamp: ON ON
LOCK IND [ON/OFF] Condition of 4WD shift
indicator lamp (Lock indi-
cator lamp) Lock indicator lamp of 4WD shift indicator lamp: OFF
OFF
Lock indicator lamp of 4WD shift indicator lamp: ON ON
4L IND [ON/OFF] Condition of 4LO indica-
tor lamp condition 4LO indicator lamp: OFF
OFF
4LO indicator lamp: ON ON
Monitored item [Unit]
Content ConditionDisplay value

TROUBLE DIAGNOSISTF-39
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Revision: November 2009 2006 QX56
Specifications Between Transfer Control Unit Terminals
TRANSFER CONTROL UNIT TERMINAL CONNECTOR LAYOUT
ATP IND [ON/OFF]Condition of ATP indica-
tor lamp ATP indicator lamp: ON
ON
ATP indicator lamp: OFF OFF
SHIFT POS SW1 [ON/
OFF] Condition of actuator
position switch 1
(Low)

Vehicle stopped

Engine running

A/T selector lever “
N” posi-
tion

Brake pedal depressed 4WD shift switch: 4LO
ON
4WD shift switch: 2WD,
AUTO or 4H OFF
SHIFT POS SW2 [ON/
OFF] Condition of actuator
position switch 2
(High)

Vehicle stopped

Engine running

A/T selector lever “
N” posi-
tion

Brake pedal depressed 4WD shift switch: 4H,
AUTO or 2WD
ON
4WD shift switch: 4LO OFF
SHIFT ACT1 [ON/OFF] Output condition to actu-
ator motor (High)

Vehicle stopped

Engine running

A/T selector lever “
N” posi-
tion

Brake pedal depressed 4WD shift switch: 4H to
4LO (
“Wait ” function is
operating.) ON
Except the above OFF
SHIFT AC MON1 [ON/
OFF] Check signal for transfer
control unit signal output

Vehicle stopped

Engine running

A/T selector lever “
N” posi-
tion

Brake pedal depressed 4WD shift switch: 4H to
4LO (
“Wait ” function is
operating.) ON
Except the above OFF
SHIFT ACT2 [ON/OFF] Output condition to actu-
ator motor (Low)

Vehicle stopped

Engine running

A/T selector lever “
N” posi-
tion

Brake pedal depressed 4WD shift switch: 4LO to
4H (
“Wait ” function is
operating.) ON
Except the above OFF
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 depressed 4WD shift switch: 4LO to
4H (
“Wait ” function is
operating.) 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 driving Approximately
matches the out-
put shaft speed.
AT GEAR POSI [1/2/3/4/
5] Condition of A/T selec-
tor lever position
Displays actual A/T gear position.
1/2/3/4/5
Monitored item [Unit]
Content ConditionDisplay value
WDIA0204E

TF-40
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
NOTE:
Data are reference value and are measured between each terminal and ground.
Te r m i n a lWire
color Item
ConditionData (Approx.)
1 GR 2-4WD shift solenoid valve

Vehicle stopped

Engine running

A/T selector lever
“ N ” position

Brake pedal
depressed 4WD shift switch: 2WD
0V
4WD shift switch: AUTO, 4H or 4LO Battery voltage
2 B/W 4WD shift indicator lamp
(2WD indicator lamp) 2WD indicator lamp: OFF
Battery voltage
2WD indicator lamp: ON 0V
3 B Ground Always0V
4 Y/L Transfer shift high relay

Vehicle stopped

Engine running

A/T selector lever
“ N ” position

Brake pedal
depressed 4WD shift switch: 4H to 4LO (
“Wait ” func-
tion is operating.) Battery voltage
Except the above 0V
5 W/B 4WD warning lamp 4WD warning lamp: ON
0V
4WD warning lamp: OFF Battery voltage
6 B Ground Always0V
7 L CAN-H ——
8 P CAN-L ——
9G/W 4WD shift switch
(2WD) Ignition switch: ON4WD shift switch: 2WD
Battery voltage
4WD shift switch: AUTO, 4H or 4LO 0V
10 L/W Transfer dropping resistor

Vehicle stopped

Engine running

A/T selector lever
“ N ” position

Brake pedal
depressed 4WD shift switch: AUTO 4 - 14V
4WD shift switch: 2WD, 4H or 4LO Less than 1V
11 L 4WD 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 lamp 4LO 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
depressed 4WD shift switch: 4LO to 4H (
“Wait ” func-
tion is operating.) Battery voltage
Except the above 0V

TROUBLE DIAGNOSISTF-41
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Revision: November 2009 2006 QX56
14 LG Transfer motor relay

Accelerator pedal
depressed

Vehicle stopped

Engine running

Brake pedal
depressed4WD shift switch: 2WD Battery 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 (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
selector lever “P ” position) 0V
15 L/B ATP warning lamp ATP indicator lamp: ON
0V
ATP indicatorlamp: OFF Battery voltage
16 Y/R Power supply Ignition switch: ON
Battery voltage
Ignition switch: OFF 0V
18 O 4WD shift switch
(4H)
Ignition switch: ON4WD shift switch: 4H
Battery voltage
4WD shift switch: 2WD, AUTO or 4LO 0V
19 L Clutch pressure solenoid
valve

Vehicle stopped

Engine running

A/T selector lever
“
N ” position

Brake pedal
depressed 4WD shift switch: AUTO
1.5 - 3V
4WD shift switch: 2WD, 4H or 4LO Less than 1V
21 BR 4WD 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 supply Ignition switch: ON
Battery voltage
Ignition switch: OFF 0V
23 R 4WD shift switch
(4LO) Ignition switch: ON4WD shift switch: 4LO
Battery voltage
4WD shift switch: 2WD, AUTO or 4H 0V
24 LG/R 4WD shift switch
(AUTO) Ignition switch: ON4WD shift switch: AUTO
Battery voltage
4WD shift switch: 2WD, 4H or 4LO 0V
25 V Neutral-4LO switch

Vehicle stopped

Engine running

A/T selector lever
“ N ” position

Brake pedal
depressed 4WD shift switch: 2WD, AUTO or 4H Battery voltage
4WD shift switch: 4H to 4LO (While actua-
tor motor is operating.)
Battery volt-
age
→ 0V
4WD shift switch: 4LO to 4H (While actua-
tor motor is operating.) 0V
→ Battery
voltage
4WD shift switch: 4LO 0V
27 W/L Actuator position switch 2
(High)

Vehicle stopped

Engine running

A/T selector lever
“
N ” position

Brake pedal
depressed 4WD shift switch: 4H, AUTO or 2WD 0V
4WD shift switch: 4LO
Battery voltage
28 B/G Sensor ground Always0V
29 L/W Ignition switch monitor Ignition switch: ON
Battery voltage
Ignition switch: OFF 0V
Terminal
Wire
color Item
ConditionData (Approx.)

TF-42
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
30 SB Shut off relayIgnition switch: ON
0V
Ignition switch: OFF Battery voltage
31 G Transfer fluid temperature
sensor Ignition switch: ONTransfer fluid temperature approx. 20°C
(68
°F) 1.1V
Transfer fluid temperature approx. 80°C
(176 °F) 0.3V
33 R/L Transfer shift high relay
monitor

Vehicle stopped

Engine running

A/T selector lever
“
N ” position

Brake pedal
depressed 4WD 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 ” position 4WD shift switch: AUTO or 4H (
“Wait ”
function is not operating.) 0V

Vehicle stopped

Engine running4WD shift switch: 2WD (
“Wait ” function is
not operating.) Battery voltage
35 BR/
W Line pressure switch

Ignition switch: ON

A/T selector lever “
D” position

4WD shift switch: AUTO 0V

After the vehicle
has been left at
room temperature
for 5 minutes and
more with ignition
switch in “
OFF”
position.

Ignition switch: ON

A/T selector lever: “P ” or "N" position

4WD shift switch: other than AUTO Battery voltage
40 L ATP switch

Vehicle stopped

Engine running

A/T selector lever
“ N ”

Brake pedal
depressed 4WD shift switch: 4H to 4LO or 4LO to 4H
(While actuator motor is operating.)
0V
Except the above Battery voltage
41 R Transfer motor relay moni-
tor

Accelerator pedal
depressed

Vehicle stopped

Engine running

Brake pedal
depressed 4WD shift switch: 2WD 0V
4WD shift switch: AUTO or 4LO (A/T
selector 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
selector lever “P ” position) Battery voltage
Te r m i n a l
Wire
color Item
ConditionData (Approx.)

TROUBLE DIAGNOSISTF-43
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Revision: November 2009 2006 QX56
CAUTION:
When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.42 P/G
Transfer shift low relay
monitor

Vehicle stopped

Engine running

A/T selector lever
“
N ” position

Brake pedal
depressed 4WD 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
depressed 4WD shift switch: 2WD, AUTO or 4H Battery voltage
4WD shift switch: 4H to 4LO (While actua-
tor motor is operating.)
Battery volt-
age
→ 0V
4WD shift switch: 4LO to 4H (While actua-
tor motor is operating.) 0V
→ Battery
voltage
4WD shift switch: 4LO 0V
44 LG/B Actuator position switch 1
(Low)

Vehicle stopped

Engine running

A/T selector lever
“
N ” position

Brake pedal
depressed 4WD shift switch: 4LO
0V
4WD shift switch: 2WD, AUTO or 4H Battery voltage
45 B Ground Always0V
47 W Power supply
(Memory back-up) Ignition switch: ON
Battery voltage
Ignition switch: OFF Battery voltage
Terminal
Wire
color Item
ConditionData (Approx.)