relay INFINITI QX56 2006 Factory Service Manual

TROUBLE DIAGNOSISTF-41
CE F
G H
I
J
K L
M A
B
TF
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
CE F
G H
I
J
K L
M A
B
TF
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.)

TROUBLE DIAGNOSISTF-45
CE F
G H
I
J
K L
M A
B
TF
Revision: November 2009 2006 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: November 20092006 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.TF-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.
TF-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

TF-48
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
P POSI SW AT [ON/OFF]ז ד
P ” position signal of A/T PNP switch status is
displayed.
Signal input with CAN communication line.
ABS OPER SW [ON/OFF] ×– ×ABS operation signal status is displayed.
Signal input with CAN communication line.
VDC OPER SW [ON/OFF] ×– ×VDC operation signal status is displayed.
Signal input with CAN communication line.
TCS OPER SW [ON/OFF] ×– ×TCS operation signal status is displayed.
Signal input with CAN communication line.
THROTTLE POSI [0.0/8] – ×× Thottle position status is displayed.
Signal input with CAN communication line.
4WD MODE [AUTO/LOCK/2WD/4L] –×× Control status of 4WD recognized by transfer
control unit. (AUTO, 4H, 2WD or 4LO)
VHCL/S COMP [km/h] or [mph] – ×× Vehicle speed recognized by transfer control
unit.
COMP CL TORQ [kgm] – ×× Calculated torque recognized by transfer
control unit.
DUTY SOLENOID [%] – ×× Control value of clutch pressure solenoid.
2-4WD SOL [ON/OFF] –×× Output condition to 2-4WD solenoid.
2-4WD SOL MON [ON/OFF] – – ×Check signal for transfer control unit signal
output.
MOTOR RELAY [ON/OFF] – ×× Transfer motor relay signal status is dis-
played.
MOTOR RELAY MON [ON/OFF] – – ×Check signal for transfer control unit signal
output.
4WD FAIL LAMP [ON/OFF] – ×× Control status of 4WD warning lamp is dis-
played.
2WD IND [ON/OFF] ––×Control status of 4WD shift indicator lamp
(2WD indicator lamp) is displayed.
AUTO IND [ON/OFF] ––×Control status of 4WD shift indicator lamp
(2WD and AUTO indicator lamp) is displayed.
LOCK IND [ON/OFF] ––×Control status of 4WD shift indicator lamp
(2WD, AUTO and Lock indicator) is dis-
played.
4L IND [ON/OFF] ––×Control status of 4LO indicator lamp is dis-
played.
ATP IND [ON/OFF] ––×Control status of ATP warning lamp is dis-
played.
SHIFT POS SW1 [ON/OFF] ×– ×Actuator position switch 1 (Low) signal status
is displayed.
SHIFT POS SW2 [ON/OFF] ×– ×Actuator position switch 2 (high) signal status
is displayed.
SHIFT ACT1 [ON/OFF] –×× Output condition to actuator motor (clock-
wise)
SHIFT AC MON1 [ON/OFF] ×– ×Check signal for transfer control unit signal
output
SHIFT ACT2 [ON/OFF] –×× Output condition to actuator motor (counter-
clockwise)
SHIFT AC MON2 [ON/OFF] ×– ×Check signal for transfer control unit signal
output
Monitored item (Unit)
Monitor item selection
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS SELEC-
TION FROM MENU

TROUBLE DIAGNOSISTF-51
CE F
G H
I
J
K L
M A
B
TF
Revision: November 2009 2006 QX56
Diagnostic Procedure
1. Warm up engine.
2. Move A/T selector lever to “P” position.
3. Turn 4WD shift switch to “2WD” position.
4. Turn ignition switch “ON” and “OFF ” at least twice, and then turn ignition switch “OFF”.
5. Turn 4WD shift switch to “AUTO” position.
6. Turn ignition switch “ON”. (Do not start engine.)
7. 4WD warning lamp ON. If 4WD warning lamp does not turn ON, refer to TF-121, "
4WD Warning Lamp Does Not Turn ON" .
8. Move A/T selector lever to “R” position.
9. Turn 4WD shift switch to “2WD”, “AUTO ” and “2WD ” in order.
10. Move A/T selector lever to “D” position.
11. Turn 4WD shift switch to “4H”, “AUTO ” and “4H” in order.
12. Move A/T selector lever to “N” position.
13. Turn 4WD shift switch to “AUTO” position.
14. Move A/T selector lever to “P” position.
15. Read the flickering of 4WD warning lamp. Refer to TF-51, "
Judgement Self-diagnosis" .
Judgement Self-diagnosis
When a malfunction is detected, the malfunction route is indicated by flickering of the 4WD warning lamp.
PDIA0227E
Flickering pattern or
flickering condition Items
Malfunction Check items
2 Output shaft revolution
signal (from TCM)

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)"
3
Clutch pressure sole-
noid signal
Proper voltage is not applied to clutch pressure solenoid
valve due to open or short circuit. TF-86, "Clutch Pres-
sure Solenoid"
4
2-4WD solenoid signal
Proper voltage is not applied to 2-4WD solenoid valve
due to open or short circuit. TF-91, "2-4WD Sole-
noid"
5
Transfer motor
Motor does not operate properly due to open or short cir-
cuit in transfer motor or motor relay. TF-95, "Transfer Motor"
6
Vehicle speed signal
(from ABS)

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

Improper signal is input while driving. TF-58, "
Vehicle Speed
Sensor (ABS)"
7
CAN communication
Malfunction has been detected from CAN communica-
tion line. TF-113, "CAN Commu-
nication Line"
8
AD converter
AD converter system of transfer control unit is malfunc-
tioning. TF-54, "Power Supply
Circuit For Transfer
Control Unit"

TF-52
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
9Transfer fluid tempera-
ture

Signal voltage from fluid temperature sensor is abnor-
mally high (Transfer fluid temperature is abnormally low)
while driving. TF-102, "Transfer Fluid
Temperature"
10
Neutral-4LO switch
Improper signal from neutral-4LO switch is input due to
open or short circuit. TF-59, "Neutral-4LO
Switch"
11
Clutch pressure switch

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 Pres-
sure Switch"
12
Line pressure switch

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"
13
Engine speed signal
(from ECM)

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)"
14
Throttle position sen-
sor (from ECM)

Malfunction is detected in accelerator pedal position sig-
nal that is output from ECM through CAN communica-
tion.

Signal voltage from accelerator pedal position sensor is
abnormally high or low. TF-111, "
Throttle Posi-
tion Signal (ECM)"
15
Power supply
Power supply voltage for transfer control unit is abnor-
mally low while driving. TF-54, "Power Supply
Circuit For Transfer
Control Unit"
16
4WD shift switch
More than two switch inputs are simultaneously detected
due to short circuit of 4WD shift switch. TF-62, "4WD Shift
Switch"
17
ABS operation signal
(from ABS)

Malfunction is detected in ABS operation signal that is
output from ABS actuator and electric unit (control unit)
through CAN communication. TF-111, "ABS Operation
Signal (ABS)"
18
Wait detection switch
Improper signal from wait detection switch is input due to
open or short circuit. TF-66, "Wait Detection
Switch"
19
Actuator motor

Motor does not operate properly due to open or short cir-
cuit 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", TF-54, "Power
Supply Circuit For
Transfer Control Unit"
20
Actuator position
switch

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 Posi-
tion Switch"
21
Actuator circuit

Transfer control device actuator circuit is shorted or
open. (Malfunctions are detected when motor relay cir-
cuit is open/shorted or relay transfer shift circuit is open/
shorted.)

Malfunction occurs in transfer control device drive circuit. TF-81, "
Transfer Con-
trol Device"

Malfunction is detected in transfer shut off relay.
TF-54, "
Power Supply
Circuit For Transfer
Control Unit"
22
VDC operation signal
(from VDC)

Malfunction is detected in VDC operation signal that is
output from ABS actuator and electric unit (control unit)
through CAN communication. TF-112, "VDC Opera-
tion Signal (ABS)"
23
TCS operation signal
(from TCS)

Malfunction is detected in TCS operation signal that is
output from ABS actuator and electric unit (control unit)
through CAN communication. TF-112, "TCS Opera-
tion Signal (ABS)"
Flickering pattern or
flickering condition Items
Malfunction Check items

TF-54
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: November 20092006 QX56
TROUBLE DIAGNOSIS FOR SYSTEMPFP:00000
Power Supply Circuit For Transfer Control UnitEDS002I4
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.Monitored item [Unit]
Content ConditionDisplay value
BATTERY VOLT [V] Power supply voltage for
transfer control unit Ignition switch: ON
Battery voltage
Te r m i n a lWire
color Item
ConditionData (Approx.)
3 B Ground Always0V
6 B Ground Always0V
16 Y/R Power supply Ignition switch: ON
Battery voltage
Ignition switch: OFF
(5 seconds after Ignition switch is turned OFF) 0V
22 Y/R Power supply Ignition switch: ON
Battery voltage
Ignition switch: OFF
(5 seconds after Ignition switch is turned OFF) 0V
29 L/W Ignition switch monitor Ignition switch: ON
Battery voltage
Ignition switch: OFF 0V
30 SB Shut off relay Ignition switch: ON
0V
Ignition switch: OFF
(5 seconds after Ignition switch is turned OFF) Battery voltage
45 B Ground Always0V
47 W Power supply
(Memory back-up) Ignition switch: ON
Battery voltage
Ignition switch: OFF Battery voltage

TROUBLE DIAGNOSIS FOR SYSTEMTF-55
CE F
G H
I
J
K L
M A
B
TF
Revision: November 2009 2006 QX56
DIAGNOSTIC PROCEDURE
1. CHECK POWER SUPPLY
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Connect transfer control unit harness connector.
3. Check voltage between transfer control unit harness connector terminals and ground.
4. Turn ignition switch “ON”. (Do not start engine.)
5. Check voltage between transfer control unit harness connector terminals and ground.
OK or NG
OK >> GO TO 2.
NG >> Check the following. If any items are damaged, repair or replace damaged parts.

10A fuses No. 26 located in fuse and fusible link box and No. 59 located in the fuse and relay
box. Refer to PG-4, "
POWER SUPPLY ROUTING CIRCUIT" .

20A fuse No. 53 located in the IPDM E/R. Refer to PG-4, "POWER SUPPLY ROUTING CIR-
CUIT" .

Harness for short or open between battery and transfer control unit harness connector termi-
nals 47.

Harness for short or open between battery and transfer control unit harness connector terminal
29.

Harness for short or open between battery and transfer shut off relay harness connector E69
terminal 1, and 3.

Harness for short or open between transfer shut off relay harness connector E69 terminal 2
and transfer control unit harness connector terminal 30.

Harness for short or open between transfer shut off relay harness connector E69 terminal 5
and transfer control unit harness connector terminals 16 and 22.

Battery and ignition switch. Refer to PG-4, "POWER SUPPLY ROUTING CIRCUIT" .

Transfer shut off relay. Refer to TF-57, "COMPONENT INSPECTION" .
ConnectorTerminal Voltage (Approx.)
E142 16 - Ground
0V
22 - Ground
E143 29 - Ground
30 - Ground
Battery voltage
47 - Ground
WDIA0165E
Connector Terminal Voltage (Approx.)
E142 16 - Ground
Battery voltage
22 - Ground
E143 29 - Ground
30 - Ground
0V
47 - Ground Battery voltage
WDIA0166E