2007 INFINITI QX56 relay

TROUBLE DIAGNOSIS
TF-37
< SERVICE INFORMATION >
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VHCL/S COMP [km/h] or
[mph]Vehicle speedVehicle stopped 0 km/h (0 MPH)
Vehicle running
CAUTION:
Check air pressure of tire under standard condition.Approximately
equal to the indica-
tion on speedome-
ter (Inside of
±10%)
COMP CL TORQ [kgm]Condition of control
torque• Vehicle stopped
• Engine running
• A/T selector lever “N” posi-
tion
• Brake pedal depressed4WD shift switch: 2WD 0 kg-m
4WD shift switch: AUTO39 - 1,353 N·m
(4 - 138 kg-m, 29 -
998 ft-lb)
4WD shift switch: 4H or
4LO1,353 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 depressed4WD shift switch: 2WD 4%
4WD shift switch: AUTO 96 - 4%
4WD shift switch: 4H or
4LO4%
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 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” posi-
tion
• 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
MOTOR RELAY [ON/
OFF]Condition of transfer mo-
tor 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” po-
sition)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 (Ex-
cept for A/T selector lever
“P” position)ON Monitored item [Unit] Content Condition Display value

TF-38
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
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” po-
sition)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 (Ex-
cept 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 in-
dicator lamp (2WD indi-
cator 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 in-
dicator lamp (AUTO indi-
cator 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 in-
dicator 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
ATP IND [ON/OFF]Condition of ATP indica-
tor lamp ATP indicator lamp: ON ON
AT P i n d i c a t o r l a m p : O F F O F F
SHIFT POS SW1 [ON/
OFF]Condition of actuator po-
sition 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 po-
sition 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
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 op-
erating.)ON
Except the above OFF Monitored item [Unit] Content Condition Display value

TROUBLE DIAGNOSIS
TF-39
< SERVICE INFORMATION >
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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 >
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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.

TROUBLE DIAGNOSIS
TF-43
< SERVICE INFORMATION >
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CONSULT-II START PROCEDURE
Refer to GI-36, "CONSULT-II Start Procedure" .
SELF-DIAG RESULT MODE
Operation Procedure
1. Perform “CONSULT-II Start Procedure”. Refer to GI-36, "CONSULT-II Start 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-53, "
Transfer Control Unit"
CONTROL UNIT 2
[P1803]• Malfunction is detected in the memory (ROM) system of transfer
control unit.TF-53, "Transfer Control Unit"
CONTROL UNIT 3
[P1804]• Malfunction is detected in the memory (EEPROM) system of trans-
fer control unit.TF-53, "Transfer Control Unit"
VHCL SPEED SEN·AT
[P1807]• Malfunction is detected in output shaft revolution signal that is out-
put from TCM through CAN communication.
• Improper signal is input while driving.TF-53, "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-54, "Vehicle Speed Sensor
(ABS)"
CONTROL UNIT 4
[P1809]• AD converter system of transfer control unit is malfunctioning.TF-53, "Transfer Control Unit"
4L POSI SW TF
[P1810]• Improper signal from neutral-4LO switch is input due to open or
short circuit.TF-54, "Neutral-4LO Switch"
BATTERY VOLTAGE
[P1811]• Power supply voltage for transfer control unit is abnormally low
while driving.TF-51, "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-57, "4WD Shift Switch"
4WD DETECT SWITCH
[P1814]• Improper signal from wait detection switch is input due to open or
short circuit.TF-60, "Wait Detection Switch"
PNP SW/CIRC
[P1816]• When A/T PNP switch signal is malfunction or communication er-
ror between the vehicles.TF-63, "PNP Switch Signal
(TCM)"
SHIFT ACTUATOR
[P1817]• Motor does not operate properly due to open or short circuit in ac-
tuator 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-64, "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-69, "Actuator Position Switch"

TF-44
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
CAUTION:
• If “CAN COMM CIRCUIT [U1000]” is displayed with other DTCs, first perform the trouble diagnosis for CAN communication
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” position
on A/T PNP switch. When there is nothing wrong with the electrical system, check the hydraulic system.
How to Erase Self-diagnostic Results
1. Perform applicable inspection of malfunctioning item and then repair or replace.
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-72, "Transfer Control Device"
Malfunction is detected in transfer shut off relay.TF-51, "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-76, "Engine Speed Signal
(ECM)"
DUTY SOLENOID
[P1822]• Proper voltage is not applied to clutch pressure solenoid valve
due to open or short circuit.TF-76, "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-80, "2-4WD Solenoid"
MOTOR RELAY
[P1824]• Motor does not operate properly due to open or short circuit in
transfer motor or motor relay.TF-84, "Transfer Motor"
OIL TEMP SEN
[P1826]• Signal voltage from fluid temperature sensor is abnormally high
(Transfer fluid temperature is abnormally low) while driving.TF-90, "Transfer Fluid Tempera-
ture"
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-92, "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-94, "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 abnormal-
ly high or low.TF-97, "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 commu-
nication.TF-97, "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 commu-
nication.TF-98, "VDC Operation Signal
(ABS)"
TCS OP SIG
[P1832]• Malfunction is detected in TCS operation signal that is output from
ABS through CAN communication.TF-98, "TCS Operation Signal
(ABS)"
CAN COMM CIRCUIT
[U1000]• Malfunction has been detected from CAN communication line.TF-99, "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