2005 INFINITI QX4 4WD

TROUBLE DIAGNOSIS
TF-39
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Revision: October 20052005 QX56
MOTOR RELAY MON
[ON/OFF]Check signal for transfer
control unit signal output

Accelerator pedal
depressed

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
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 lamp4WD 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 condition4LO indicator lamp: OFF OFF
4LO indicator lamp: ON ON
AT P I N D [O N / O F F ]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 depressed4WD shift switch: 4LO ON
4WD shift switch: 2WD,
AUTO or 4HOFF
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 depressed4WD shift switch: 4H,
AUTO or 2WDON
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 depressed4WD 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 depressed4WD shift switch: 4H to
4LO (“Wait” function is
operating.)ON
Except the above OFF Monitored item [Unit] Content Condition Display value

TF-40
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
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 ACT2 [ON/OFF]Output condition to actu-
ator motor (Low)

Vehicle stopped

Engine running

A/T selector lever “N” posi-
tion

Brake pedal depressed4WD 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 depressed4WD 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 drivingApproximately
matches the out-
put shaft speed.
AT GEAR POSI [1/2/3/4/
5]Condition of A/T selec-
tor lever positionDisplays actual A/T gear position. 1/2/3/4/5 Monitored item [Unit] Content Condition Display value
WDIA0204E
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
depressed4WD 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
depressed4WD 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

TROUBLE DIAGNOSIS
TF-41
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Revision: October 20052005 QX56
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
10 L/W Transfer dropping resistor

Vehicle stopped

Engine running

A/T selector lever
“N” position

Brake pedal
depressed4WD 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
depressed4WD 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
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 lampATP indicator lamp: ON 0V
ATP indicator lamp: 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
depressed4WD 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 Te r m i n a lWire
colorItem Condition Data (Approx.)

TF-42
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
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
25 V Neutral-4LO switch

Vehicle stopped

Engine running

A/T selector lever
“N” position

Brake pedal
depressed4WD 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/LActuator position switch 2
(High)

Vehicle stopped

Engine running

A/T selector lever
“N” position

Brake pedal
depressed4WD 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
depressed4WD 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”
function 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”
position.

Ignition switch: ON

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

4WD shift switch: other than AUTOBattery voltage Te r m i n a lWire
colorItem Condition Data (Approx.)

TROUBLE DIAGNOSIS
TF-43
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Revision: October 20052005 QX56
CAUTION:
When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.40 L 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.)0V
Except the above Battery voltage
41 RTransfer motor relay moni-
tor

Accelerator pedal
depressed

Vehicle stopped

Engine running

Brake pedal
depressed4WD 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
42 P/GTransfer shift low relay
monitor

Vehicle stopped

Engine running

A/T selector lever
“N” position

Brake pedal
depressed4WD 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
depressed4WD 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/BActuator position switch 1
(Low)

Vehicle stopped

Engine running

A/T selector lever
“N” position

Brake pedal
depressed4WD 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.)

TF-44
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
CONSULT-II Function (ALL MODE AWD/4WD)EDS002HK
FUNCTION
CONSULT-II can display each diagnostic item using the diagnostic test modes shown following.
CONSULT-II SETTING PROCEDURE
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carry out CAN communication.
NOTE:
For details, refer to the separate “CONSULT-II Operations Manual”.
1. Turn ignition switch “OFF”.
2. Connect CONSULT-II and CONSULT-II CONVERTER to data
link connector on vehicle.
3. Turn ignition switch “ON”.
4. Touch “START (NISSAN BASED VHCL)”.
5. Touch “ALL MODE AWD/4WD”.
If “ALL MODE AWD/4WD” is not indicated, go to GI-39, "
CON-
SULT-II Data Link Connector (DLC) Circuit" .
6. Perform each diagnostic test mode according to each service
procedure.
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 con-
trol unit and received data is displayed.
CAN DIAG SUPPORT
MNTRThe results of transmit/receive diagnosis of CAN communication can be read.
ECU PART NUMBER Transfer control unit part number can be read.
BBIA0369E
BCIA0029E
BCIA0030E

TROUBLE DIAGNOSIS
TF-45
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Revision: October 20052005 QX56
SELF-DIAG RESULT MODE
Operation Procedure
1. Perform “CONSULT-II SETTING PROCEDURE”. Refer to TF-44, "CONSULT-II SETTING PROCEDURE"
.
2. With engine at idle, touch “SELF-DIAG RESULTS”.
Display shows malfunction experienced since the last erasing
operation.
NOTE:

The details for “TIME” are as follow:
–“0”: Error currently detected with transfer control unit.
–Except for “0”: Error detected in the past and memorized
with transfer control unit.
Detects frequency of driving after DTC occurs (frequency
of turning ignition switch “ON/OFF”).
Display Item List
SDIA2687E
Items (CONSULT-II screen
terms)Diagnostic item is detected when... Check item
CONTROL UNIT 1
[P1802]

Malfunction is detected in the memory (RAM) system of transfer
control unit.TF-57, "Transfer Control Unit"
CONTROL UNIT 2
[P1803]
Malfunction is detected in the memory (ROM) system of transfer
control unit.TF-57, "Transfer Control Unit"
CONTROL UNIT 3
[P1804]
Malfunction is detected in the memory (EEPROM) system of
transfer control unit.TF-57, "Transfer Control Unit"
VHCL SPEED SEN·AT
[P1807]
Malfunction is detected in output shaft revolution signal that is
output from TCM through CAN communication.

Improper signal is input while driving.TF-58, "
Output Shaft Revolution
Signal (TCM)"
VHCL SPEED SEN·ABS
[P1808]

Malfunction is detected in vehicle speed signal that is output from
ABS actuator and electric unit (control unit) through CAN commu-
nication.

Improper signal is input while driving.TF-58, "
Vehicle Speed Sensor
(ABS)"
CONTROL UNIT 4
[P1809]
AD converter system of transfer control unit is malfunctioning.TF-57, "Transfer Control Unit"
4L POSI SW TF
[P1810]
Improper signal from neutral-4LO switch is input due to open or
short circuit.TF-59, "Neutral-4LO Switch"
BATTERY VOLTAGE
[P1811]
Power supply voltage for transfer control unit is abnormally low
while driving.TF-54, "Power Supply Circuit For
Transfer Control Unit"
4WD MODE SW
[P1813]
More than two switch inputs are simultaneously detected due to
short circuit of 4WD shift switch.TF-62, "4WD Shift Switch"
4WD DETECT SWITCH
[P1814]
Improper signal from wait detection switch is input due to open or
short circuit.TF-66, "Wait Detection Switch"
PNP SW/CIRC
[P1816]
When A/T PNP switch signal is malfunction or communication
error between the vehicles.TF-69, "PNP Switch Signal
(TCM)"
SHIFT ACTUATOR
[P1817]

Motor does not operate properly due to open or short circuit in
actuator motor.

Malfunction is detected in the actuator motor. (When 4WD shift
switch is operated and actuator motor is not operated)

Malfunction is detected in transfer shift high relay and transfer
shift low relay.TF-70, "
Actuator Motor"
SHIFT ACT POSI SW
[P1818]
Improper signal from actuator position switch is input due to open
or short circuit.

Malfunction is detected in the actuator position switch.TF-77, "
Actuator Position
Switch"

TF-46
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
CAUTION:

If “CAN COMM CIRCUIT [U1000]” is displayed with other DTCs, first perform the trouble diagnosis for CAN communica-
tion line.

If “VHCL SPEED SEN·AT [P1808]”, “ABS OP SIG [P1830]”, “VDC OP SIG [P1831]” or “TCS OP SIG [P1832]” is displayed,
first perform the trouble diagnosis for ABS system.

If “VHCL SPEED SEN·AT [P1808]”, is displayed, first perform the trouble diagnosis for A/T system.
NOTE:

If "SHIFT ACT POSI SW [P1818]" or “SHIFT ACT CIR [P1819]” is displayed, first erase self-diagnostic results. ("SHIFT ACT POSI
SW [P1818]" or “SHIFT ACT CIR [P1819]” may be displayed after installing transfer control unit or transfer assembly.)

If “CL PRES SW [P1827]” or “LINE PRES SW [P1828]” is displayed only while driving in reverse, check the continuity of “R” posi-
tion on A/T PNP switch. When there is nothing wrong with the electrical system, check the hydraulic system. SHIFT ACT CIR
[P1819]

Transfer control device actuator circuit is shorted or open. (Mal-
functions are detected when transfer shift relay circuit is open/
shorted or relay monitor circuit is open/shorted.)

Malfunction occurs in transfer control device drive circuit.

Malfunction is detected in transfer shut off relay.TF-81, "
Transfer Control Device"
Malfunction is detected in transfer shut off relay.TF-54, "Power Supply Circuit For
Transfer Control Unit"
ENGINE SPEED SIG
[P1820]
Malfunction is detected in engine speed signal that is output from
ECM through CAN communication.

Improper signal is input while driving.TF-85, "
Engine Speed Signal
(ECM)"
DUTY SOLENOID
[P1822]
Proper voltage is not applied to clutch pressure solenoid valve
due to open or short circuit.TF-86, "Clutch Pressure Sole-
noid"
2-4WD SOLENOID
[P1823]
Proper voltage is not applied to 2-4WD solenoid valve due to
open or short circuit.TF-91, "2-4WD Solenoid"
MOTOR RELAY
[P1824]
Motor does not operate properly due to open or short circuit in
transfer motor or motor relay.TF-95, "Transfer Motor"
OIL TEMP SEN
[P1826]
Signal voltage from fluid temperature sensor is abnormally high
(Transfer fluid temperature is abnormally low) while driving.TF-102, "Transfer Fluid Temper-
ature"
CLUTCH PRES SW
[P1827]
Improper signal from clutch pressure switch is input due to open
or short circuit.

Malfunction occurs in clutch pressure switch or hydraulic circuit.TF-105, "
Clutch Pressure
Switch"
LINE PRES SW
[P1828]
Improper signal from line pressure switch is input due to open or
short circuit.

Malfunction occurs in line pressure switch or hydraulic circuit.TF-108, "
Line Pressure Switch"
THROTTLE POSI SEN
[P1829]

Malfunction is detected in accelerator pedal position signal that is
output from ECM through CAN communication.

Signal voltage from accelerator pedal position sensor is abnor-
mally high or low.T F - 111 , "
Throttle Position Signal
(ECM)"
ABS OP SIG
[P1830]
Malfunction is detected in ABS operation signal that is output
from ABS actuator and electric unit (control unit) through CAN
communication.T F - 111 , "ABS Operation Signal
(ABS)"
VDC OP SIG
[P1831]
Malfunction is detected in VDC operation signal that is output
from ABS actuator and electric unit (control unit) through CAN
communication.TF-112, "VDC Operation Signal
(ABS)"
TCS OP SIG
[P1832]
Malfunction is detected in TCS operation signal that is output
from ABS through CAN communication.TF-112, "TCS Operation Signal
(ABS)"
CAN COMM CIRCUIT
[U1000]
Malfunction has been detected from CAN communication line.TF-113, "CAN Communication
Line"
NO DTC IS DETECTED.
FURTHER TESTING MAY
BE REQUIRED.

No NG item has been detected. — Items (CONSULT-II screen
terms)Diagnostic item is detected when... Check item