2004 INFINITI QX56 4WD

4WD SOLENOID VALVE
TF-61
C
E
F
G
H
I
J
K
L
MA
B
TF
Revision: August 20072004 QX56
4. PERFORM SELF-DIAGNOSIS
After driving for a while, perform self-diagnosis.
Refer to TF-27, "
Trouble Diagnosis without CONSULT-II" or TF-31, "Trouble Diagnosis with CONSULT-II" .
OK or NG
OK >> Inspection End.
NG >> 1. Perform transfer control unit input/output signal inspection. Refer to TF-55, "
TRANSFER CON-
TROL UNIT INSPECTION TABLE" .
2. If NG, recheck transfer control unit pin terminals for damage or loose connection with harness
connector.

TF-62
2-4WD SHIFT SOLENOID VALVE AND 4WD SHIFT SWITCH
Revision: August 20072004 QX56
2-4WD SHIFT SOLENOID VALVE AND 4WD SHIFT SWITCHPFP:00000
Diagnostic ProcedureEDS00184
1. CHECK 2-4WD SHIFT SOLENOID VALVE AND 4WD SHIFT SWITCH
Refer to TF-95, "
2-4WD SHIFT SOLENOID VALVE AND TRANS-
FER FLUID TEMPERATURE SENSOR" and TF-95, "4WD SHIFT
SWITCH" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace 2-4WD shift solenoid valve or 4WD
shift switch.
2. CHECK INPUT SIGNAL
With CONSULT-II
1. Select “ECU INPUT SIGNALS” in Data Monitor.
2. Read out ON/OFF status of “2WD SW” and “LOCK SWITCH”.
OK or NG
OK >> 1. Perform transfer control unit input/output signal
inspection. Refer to TF-55, "
TRANSFER CONTROL
UNIT INSPECTION TABLE" .
2. If NG, recheck transfer control unit pin terminals for
damage or loose connection with harness connector.
NG >> GO TO 3.
SMT778D
SMT974D

2-4WD SHIFT SOLENOID VALVE AND 4WD SHIFT SWITCH
TF-63
C
E
F
G
H
I
J
K
L
MA
B
TF
Revision: August 20072004 QX56
3. CHECK 4WD SHIFT SWITCH POWER SOURCE
1. Disconnect 4WD shift switch harness connector.
2. Turn ignition switch to ON position.
3. Check voltage between 4WD shift switch harness connector ter-
minal 1 and body ground.
OK or NG
OK >> GO TO 4.
NG >> Check the following.

No. 49 fuse (10A)

Continuity between ignition switch and 4WD shift
switch
4. CHECK HARNESS CONTINUITY
1. Turn ignition switch to OFF position.
2. Disconnect transfer control unit harness connector E142.
3. Check continuity between the following terminals.
OK or NG
OK >> GO TO 5.
NG >> Repair harness or connector.
5. PERFORM SELF-DIAGNOSIS AGAIN
After driving for a while, perform self-diagnosis again.
Refer to TF-27, "
Trouble Diagnosis without CONSULT-II" .
OK or NG
OK >> Inspection End.
NG >> 1. Perform transfer control unit input/output signal inspection. Refer to TF-55, "
TRANSFER CON-
TROL UNIT INSPECTION TABLE" .
2. If NG, recheck transfer control unit pin terminals for damage or loose connection with harness
connector. Voltage : Battery voltage
SMT852D
Connec-
torTe r m i n a l
(Wire
color)Connec-
torTe r m i na l
(Wire
color)Continu-
ity
M141
(2WD)2 (G/W)
E1429 (G/W)
Yes M141
(4H)5 (O) 18 (O)
M141
(AUTO)3 (LG/R) 24 (LG/R)
M141
(4LO)6 (R) 23 (R)
M141 4 (G/R) 1 (GR)
LDIA0069E

TF-66
TRANSFER FLUID TEMPERATURE SENSOR
Revision: August 20072004 QX56
TRANSFER FLUID TEMPERATURE SENSORPFP:00000
Diagnostic ProcedureEDS00186
1. CHECK TRANSFER FLUID TEMPERATURE SENSOR
Refer to TF-95, "
2-4WD SHIFT SOLENOID VALVE AND TRANSFER FLUID TEMPERATURE SENSOR" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace fluid temperature sensor.
2. CHECK INPUT SIGNAL
Do you have CONSULT-II?
Ye s o r N o
Yes >> GO TO 3.
No >> GO TO 4.

TF-72
CLUTCH PRESSURE SWITCH
Revision: August 20072004 QX56
CLUTCH PRESSURE SWITCHPFP:00000
Diagnostic ProcedureEDS00188
1. CHECK MALFUNCTION
Is this malfunction detected only while driving in reverse?
Ye s o r N o
Yes >> Check A/T PNP switch "R" position.

Refer to AT-109, "DTC P0705 PARK/NEUTRAL POSITION SWITCH" .
No >> GO TO 2.
2. CHECK OTHER MALFUNCTION
Are other malfunctions also detected by self-diagnosis and CONSULT-II?
Refer to TF-27, "
Trouble Diagnosis without CONSULT-II" and TF-31, "Trouble Diagnosis with CONSULT-II" .
Ye s o r N o
Yes >> Check for other malfunctions.

(When other malfunctions are eliminated, clutch pressure switch malfunction display may dis-
appear.)
No >> GO TO 3.
3. CHECK 2-4WD SHIFT SOLENOID VALVE AND 4WD SHIFT SWITCH CIRCUITS
Check 2-4WD shift solenoid valve and 4WD shift switch circuits.
OK or NG
OK >> GO TO 4.
NG >> Check, repair or replace faulty parts.
4. CHECK INPUT SIGNAL
Do you have CONSULT-II?
Ye s o r N o ?
Yes >> GO TO 5.
No >> GO TO 6.

CLUTCH PRESSURE SWITCH
TF-73
C
E
F
G
H
I
J
K
L
MA
B
TF
Revision: August 20072004 QX56
5. CHECK INPUT SIGNAL
With CONSULT-II
1. Turn ignition switch to ON position.
2. Select “ECU INPUT SIGNALS” in Data Monitor.
3. Put A/T selecor lever in D.
4. Turn 4WD shift switch to 4H and back to 2WD while reading out
ON/OFF status of "CL PRES SW".
OK or NG
OK >> GO TO 7.
NG >> Check the following.

Continuity between transfer control unit and transfer
terminal cord assembly harness connector

Clutch pressure switch.
Refer to TF-95, "
4WD SOLENOID VALVE, CLUTCH
PRESSURE SWITCH AND LINE PRESSURE
SWITCH" .
6. CHECK INPUT SIGNAL
Without CONSULT-II
1. Turn ignition switch to ON position and set 4WD shift switch to
4H position.
2. Check voltage between transfer control unit harness connector
E143 terminal 34 (BR) and ground. Refer to TF-55, "
Transfer
Control Unit Terminals and Reference Value"
OK or NG
OK >> GO TO 7.
NG >> Check the following.

Continuity between transfer control unit and transfer
terminal cord assembly harness connector

Clutch pressure switch.
Refer to TF-95, "
4WD SOLENOID VALVE, CLUTCH PRESSURE SWITCH AND LINE PRES-
SURE SWITCH" .
7. PERFORM SELF-DIAGNOSIS AGAIN
1. Check hydraulic parts.
2. After driving for a while, perform self-diagnosis again. Refer to TF-27, "
Trouble Diagnosis without CON-
SULT-II" .
OK or NG
OK >> Inspection End.
NG >> 1. Perform transfer control unit input/output signal inspection. Refer to TF-55, "
TRANSFER CON-
TROL UNIT INSPECTION TABLE" .
2. If NG, recheck transfer control unit pin terminals for damage or loose connection with harness
connector.
SMT788D
WDIA0087E
LDIA0075E

TF-74
LINE PRESSURE SWITCH
Revision: August 20072004 QX56
LINE PRESSURE SWITCHPFP:00000
Diagnostic ProcedureEDS00189
1. CHECK MALFUNCTION
Is this malfunction detected only while driving in reverse?
Ye s o r N o
Yes >> Check A/T PNP switch “R” position.

Refer to AT-109, "DTC P0705 PARK/NEUTRAL POSITION SWITCH" .
No >> GO TO 2.
2. CHECK OTHER MALFUNCTIONS
Are other malfunctions also detected by self-diagnosis and CONSULT-II?
Refer to TF-27, "
Trouble Diagnosis without CONSULT-II" and TF-31, "Trouble Diagnosis with CONSULT-II" .
Ye s o r N o
Yes >> Check for other malfunctions.

(When other malfunctions are eliminated, line pressure switch malfunction display may disap-
pear.)
No >> GO TO 3.
3. CHECK INPUT SIGNAL
Do you have CONSULT-II?
Ye s o r N O
Yes >> GO TO 4.
No >> GO TO 5.
4. CHECK INPUT SIGNAL
With CONSULT-II
1. Select “ECU INPUT SIGNALS” in Data Monitor.
2. Put A/T selector lever in D.
3. Turn the 4WD shift switch to 4H and back to 2WD while reading
out ON/OFF status of "LINE PRES SW".
OK or NG
OK >> GO TO 6.
NG >> Check the following.

Continuity between transfer control unit and transfer
terminal cord assembly harness connector

Line pressure switch
Refer to TF-95, "
4WD SOLENOID VALVE, CLUTCH
PRESSURE SWITCH AND LINE PRESSURE
SWITCH" .
SMT790D
WDIA0087E

LINE PRESSURE SWITCH
TF-75
C
E
F
G
H
I
J
K
L
MA
B
TF
Revision: August 20072004 QX56
5. CHECK INPUT SIGNAL
Without CONSULT-II
1. Turn ignition switch to ON position.
2. Check voltage between transfer control unit harness connector E143 terminal 35 (BR/W) and ground.
OK or NG
OK >> GO TO 6.
NG >> Check the following.

Continuity between transfer control unit and transfer terminal cord assembly harness connector

Line pressure switch
Refer to TF-95, "
4WD SOLENOID VALVE, CLUTCH PRESSURE SWITCH AND LINE PRES-
SURE SWITCH" .
6. PERFORM SELF-DIAGNOSIS AGAIN
1. Check hydraulic parts.
2. After driving for a while, perform self-diagnosis again. Refer to TF-27, "
Trouble Diagnosis without CON-
SULT-II" .
OK or NG
OK >> Inspection End.
NG >> 1. Perform transfer control unit input/output signal inspection. Refer to TF-55, "
TRANSFER CON-
TROL UNIT INSPECTION TABLE" .
2. If NG, recheck transfer control unit pin terminals for damage or loose connection with harness
connector. After the vehicle has
been left for at least 5
minutes at room tem-
perature with ignition
switch OFF: Approx. 0 volts should
exist.
With ignition switch in
ON, 4WD shift switch in
AUTO or 4H and A/T
selector lever in D: Battery voltage should
exist.
LDIA0076E
LDIA0077E